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Main
Date: 04 Jun 2007 08:38:09
From: VeloJon
Subject: Compact Crank Ring Differential
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According to Cyclingnews, several Giro riders were running 52/34 chain
rings for the big climbs. I thought the conventional wisdom was that
a 16-tooth differential between the 2 rings was the max for shifting
smoothness on the front der. Before I go and try a 52/34 combo,
opinions please?
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Date: 07 Jun 2007 18:45:55
From: Johnny Sunset
Subject: Re: Compact Crank Ring Differential
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On Jun 7, 12:13 pm, Bill Baka wrote:
> Dave van Tol wrote:
> > Bill Baka wrote:
> >> Russell Seaton wrote:
>
> >>> 406mm tires are about 16-18" or so in diameter. I forget if 406 tires
> >>> are closer to 16" or 18". 73x13 with 406 gets you about 100 gear
> >>> inches. 52x28 gets you about 33 gear inches. Equivalent of a
> >>> sensibly geared compact double crankset today. I think 406mm is used
> >>> by Moulton bikes and foldable bikes. Bike Friday uses 406 I think on
> >>> their touring models. 420 on their racy models.
>
> >> Got a picture? It sounds like the crank would be almost as big as the
> >> tires and you would have a ground clearance problem. I don't recall
> >> ever seeing something like that in either of my LBS's.
>
> > Now you've done it... Tom loves to post links to pictures of his
> > bikes/trikes... check the archives. I'm 99.9% sure he's talking about a
> > recumbent of some sort.
Provoking a reaction from the "upright uptights" is fun - and not to
be confused with trying to convince others to ride similar human
powered vehicles!
> I think that is likely the case, but it would still make for a good
> conversation starter, hopefully with a babe.
That bike (Wishbone) with the giant chainring provoked more freak show
reactions than anything else. My current bike is equally as odd, but
much more cute.
--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful
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Date: 07 Jun 2007 18:36:56
From: Johnny Sunset
Subject: Re: Compact Crank Ring Differential
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On Jun 7, 11:12 am, Bill Baka wrote:
> russellseat...@yahoo.com wrote:
> > On Jun 7, 12:57 am, Bill Baka wrote:
> >> Johnny Sunset wrote:
> >>> On Jun 4, 10:38 am, VeloJon wrote:
> >>>> According to Cyclingnews, several Giro riders were running 52/34 chain
> >>>> rings for the big climbs. I thought the conventional wisdom was that
> >>>> a 16-tooth differential between the 2 rings was the max for shifting
> >>>> smoothness on the front der. Before I go and try a 52/34 combo,
> >>>> opinions please?
> >>> I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
> >>> wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
> >>> and pins on the large chainring) but otherwise acceptable.
> >> If you were running a gear like that just what the hell did you have in
> >> the rear? 73/?? seems way unlikely.
> >> Bill Baka
>
> > 406mm tires are about 16-18" or so in diameter. I forget if 406 tires
> > are closer to 16" or 18". 73x13 with 406 gets you about 100 gear
> > inches. 52x28 gets you about 33 gear inches. Equivalent of a
> > sensibly geared compact double crankset today. I think 406mm is used
> > by Moulton bikes and foldable bikes. Bike Friday uses 406 I think on
> > their touring models. 420 on their racy models.
>
> Got a picture? It sounds like the crank would be almost as big as the
> tires and you would have a ground clearance problem. I don't recall ever
> seeing something like that in either of my LBS's.
See post below for picture. The big ring started life as an aluminium
alloy plate, and was custom machined into a chainring - hence the lack
of "ramps and pins" seen on modern mid to high end commercial
chainrings.
--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful
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Date: 08 Jun 2007 01:50:05
From: Bill
Subject: Re: Compact Crank Ring Differential
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Johnny Sunset wrote:
> On Jun 7, 11:12 am, Bill Baka wrote:
>> russellseat...@yahoo.com wrote:
>>> On Jun 7, 12:57 am, Bill Baka wrote:
>>>> Johnny Sunset wrote:
>>>>> On Jun 4, 10:38 am, VeloJon wrote:
>>>>>> According to Cyclingnews, several Giro riders were running 52/34 chain
>>>>>> rings for the big climbs. I thought the conventional wisdom was that
>>>>>> a 16-tooth differential between the 2 rings was the max for shifting
>>>>>> smoothness on the front der. Before I go and try a 52/34 combo,
>>>>>> opinions please?
>>>>> I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
>>>>> wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
>>>>> and pins on the large chainring) but otherwise acceptable.
>>>> If you were running a gear like that just what the hell did you have in
>>>> the rear? 73/?? seems way unlikely.
>>>> Bill Baka
>>> 406mm tires are about 16-18" or so in diameter. I forget if 406 tires
>>> are closer to 16" or 18". 73x13 with 406 gets you about 100 gear
>>> inches. 52x28 gets you about 33 gear inches. Equivalent of a
>>> sensibly geared compact double crankset today. I think 406mm is used
>>> by Moulton bikes and foldable bikes. Bike Friday uses 406 I think on
>>> their touring models. 420 on their racy models.
>> Got a picture? It sounds like the crank would be almost as big as the
>> tires and you would have a ground clearance problem. I don't recall ever
>> seeing something like that in either of my LBS's.
>
> See post below for picture. The big ring started life as an aluminium
> alloy plate, and was custom machined into a chainring - hence the lack
> of "ramps and pins" seen on modern mid to high end commercial
> chainrings.
I looked, I saw, I'm still scratching my head.
I'm not sure I would want to be seen on that thing.
The big rings would be right in the line of sight.
Bill Baka
>
> --
> Tom Sherman - Holstein-Friesland Bovinia
> The weather is here, wish you were beautiful
>
>
>
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Date: 07 Jun 2007 18:32:20
From: Johnny Sunset
Subject: Re: Compact Crank Ring Differential
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On Jun 7, 12:57 am, Bill Baka wrote:
> Johnny Sunset wrote:
> > On Jun 4, 10:38 am, VeloJon wrote:
> >> According to Cyclingnews, several Giro riders were running 52/34 chain
> >> rings for the big climbs. I thought the conventional wisdom was that
> >> a 16-tooth differential between the 2 rings was the max for shifting
> >> smoothness on the front der. Before I go and try a 52/34 combo,
> >> opinions please?
>
> > I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
> > wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
> > and pins on the large chainring) but otherwise acceptable.
>
> If you were running a gear like that just what the hell did you have in
> the rear? 73/?? seems way unlikely.
More likely than going downhill at 50 mph on a children's tricycle!
Note that I wrote ISO 406-mm drive wheel. With a Tioga Comp Pool tire,
the 73/52 chainring and 11-28 cassette results in a range of 36 to 129
gear inches.
This is the bike, at the time of purchase <http://www.ihpva.org/
incoming/2001/wbone2.jpg > and shortly after I sold it: <http://
www.liegeradinfo.de/wisbone2.jpg >.
--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful
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Date: 08 Jun 2007 01:47:01
From: Bill
Subject: Re: Compact Crank Ring Differential
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Johnny Sunset wrote:
> On Jun 7, 12:57 am, Bill Baka wrote:
>> Johnny Sunset wrote:
>>> On Jun 4, 10:38 am, VeloJon wrote:
>>>> According to Cyclingnews, several Giro riders were running 52/34 chain
>>>> rings for the big climbs. I thought the conventional wisdom was that
>>>> a 16-tooth differential between the 2 rings was the max for shifting
>>>> smoothness on the front der. Before I go and try a 52/34 combo,
>>>> opinions please?
>>> I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
>>> wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
>>> and pins on the large chainring) but otherwise acceptable.
>> If you were running a gear like that just what the hell did you have in
>> the rear? 73/?? seems way unlikely.
>
> More likely than going downhill at 50 mph on a children's tricycle!
Enough tricycle already. 23 felt like 50 at age 4 or 5 when I did it.
>
> Note that I wrote ISO 406-mm drive wheel. With a Tioga Comp Pool tire,
> the 73/52 chainring and 11-28 cassette results in a range of 36 to 129
> gear inches.
>
> This is the bike, at the time of purchase <http://www.ihpva.org/
> incoming/2001/wbone2.jpg> and shortly after I sold it: <http://
> www.liegeradinfo.de/wisbone2.jpg>.
>
> --
> Tom Sherman - Holstein-Friesland Bovinia
> The weather is here, wish you were beautiful
>
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Date: 07 Jun 2007 15:31:09
From: DirtRoadie
Subject: Re: Compact Crank Ring Differential
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VeloJon wrote:
> According to Cyclingnews, several Giro riders were running 52/34 chain
> rings for the big climbs. I thought the conventional wisdom was that
> a 16-tooth differential between the 2 rings was the max for shifting
> smoothness on the front der. Before I go and try a 52/34 combo,
> opinions please?
I have used a 53/34 for a while now (11 or 12-23 on the rear). Works
fine. However, at 34/11 the chain is verging on being slack and at
53/23 it's almost maxed out.
So I don't know how much (if any) problem there would be with a 25 or
27 on the rear, but it would require the rear deraileur to accomodate
2 or 4 more links/teeth of chain wrap.
DR
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Date: 07 Jun 2007 14:32:39
From: russellseaton1@yahoo.com
Subject: Re: Compact Crank Ring Differential
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On Jun 7, 11:12 am, Bill <b...@comcast.net > wrote:
> russellseat...@yahoo.com wrote:
> > On Jun 7, 12:57 am, Bill <b...@comcast.net> wrote:
> >> Johnny Sunset wrote:
> >>> On Jun 4, 10:38 am, VeloJon wrote:
> >>>> According to Cyclingnews, several Giro riders were running 52/34 chain
> >>>> rings for the big climbs. I thought the conventional wisdom was that
> >>>> a 16-tooth differential between the 2 rings was the max for shifting
> >>>> smoothness on the front der. Before I go and try a 52/34 combo,
> >>>> opinions please?
> >>> I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
> >>> wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
> >>> and pins on the large chainring) but otherwise acceptable.
> >> If you were running a gear like that just what the hell did you have in
> >> the rear? 73/?? seems way unlikely.
> >> Bill Baka
>
> > 406mm tires are about 16-18" or so in diameter. I forget if 406 tires
> > are closer to 16" or 18". 73x13 with 406 gets you about 100 gear
> > inches. 52x28 gets you about 33 gear inches. Equivalent of a
> > sensibly geared compact double crankset today. I think 406mm is used
> > by Moulton bikes and foldable bikes. Bike Friday uses 406 I think on
> > their touring models. 420 on their racy models.
>
> Got a picture? It sounds like the crank would be almost as big as the
> tires and you would have a ground clearance problem. I don't recall ever
> seeing something like that in either of my LBS's.
Well now, if seeing something in my local bike shop was a prerequisite
for it existing, then Shimano and factory bikes would be the only non
department store bikes on earth. Maybe you have bike shops that carry
something besides Shimano and factory bikes. Around here its Shimano
and factory bikes. Shimano and factory bikes. Shimano and factory
bikes. Thankfully there is mail order.
> Bill Baka
>
>
>
>
>
> >>> --
> >>> Tom Sherman - Holstein-Friesland Bovinia
> >>> The weather is here, wish you were beautiful- Hide quoted text -
> >> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
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Date: 08 Jun 2007 01:23:07
From: Bill
Subject: Re: Compact Crank Ring Differential
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russellseaton1@yahoo.com wrote:
> On Jun 7, 11:12 am, Bill <b...@comcast.net> wrote:
>> Got a picture? It sounds like the crank would be almost as big as the
>> tires and you would have a ground clearance problem. I don't recall ever
>> seeing something like that in either of my LBS's.
>
> Well now, if seeing something in my local bike shop was a prerequisite
> for it existing, then Shimano and factory bikes would be the only non
> department store bikes on earth. Maybe you have bike shops that carry
> something besides Shimano and factory bikes. Around here its Shimano
> and factory bikes. Shimano and factory bikes. Shimano and factory
> bikes. Thankfully there is mail order.
>
>
>
>> Bill Baka
>>
>>
Maybe my Little Bike Shops are too little. There's always Ebay.
Bill Baka
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Date: 07 Jun 2007 08:51:04
From: russellseaton1@yahoo.com
Subject: Re: Compact Crank Ring Differential
|
On Jun 7, 12:57 am, Bill <b...@comcast.net > wrote:
> Johnny Sunset wrote:
> > On Jun 4, 10:38 am, VeloJon wrote:
> >> According to Cyclingnews, several Giro riders were running 52/34 chain
> >> rings for the big climbs. I thought the conventional wisdom was that
> >> a 16-tooth differential between the 2 rings was the max for shifting
> >> smoothness on the front der. Before I go and try a 52/34 combo,
> >> opinions please?
>
> > I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
> > wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
> > and pins on the large chainring) but otherwise acceptable.
>
> If you were running a gear like that just what the hell did you have in
> the rear? 73/?? seems way unlikely.
> Bill Baka
406mm tires are about 16-18" or so in diameter. I forget if 406 tires
are closer to 16" or 18". 73x13 with 406 gets you about 100 gear
inches. 52x28 gets you about 33 gear inches. Equivalent of a
sensibly geared compact double crankset today. I think 406mm is used
by Moulton bikes and foldable bikes. Bike Friday uses 406 I think on
their touring models. 420 on their racy models.
>
>
>
>
>
> > --
> > Tom Sherman - Holstein-Friesland Bovinia
> > The weather is here, wish you were beautiful- Hide quoted text -
>
> - Show quoted text -
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Date: 07 Jun 2007 09:12:58
From: Bill
Subject: Re: Compact Crank Ring Differential
|
russellseaton1@yahoo.com wrote:
> On Jun 7, 12:57 am, Bill <b...@comcast.net> wrote:
>> Johnny Sunset wrote:
>>> On Jun 4, 10:38 am, VeloJon wrote:
>>>> According to Cyclingnews, several Giro riders were running 52/34 chain
>>>> rings for the big climbs. I thought the conventional wisdom was that
>>>> a 16-tooth differential between the 2 rings was the max for shifting
>>>> smoothness on the front der. Before I go and try a 52/34 combo,
>>>> opinions please?
>>> I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
>>> wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
>>> and pins on the large chainring) but otherwise acceptable.
>> If you were running a gear like that just what the hell did you have in
>> the rear? 73/?? seems way unlikely.
>> Bill Baka
>
> 406mm tires are about 16-18" or so in diameter. I forget if 406 tires
> are closer to 16" or 18". 73x13 with 406 gets you about 100 gear
> inches. 52x28 gets you about 33 gear inches. Equivalent of a
> sensibly geared compact double crankset today. I think 406mm is used
> by Moulton bikes and foldable bikes. Bike Friday uses 406 I think on
> their touring models. 420 on their racy models.
>
>
Got a picture? It sounds like the crank would be almost as big as the
tires and you would have a ground clearance problem. I don't recall ever
seeing something like that in either of my LBS's.
Bill Baka
>
>>
>>
>>
>>
>>> --
>>> Tom Sherman - Holstein-Friesland Bovinia
>>> The weather is here, wish you were beautiful- Hide quoted text -
>> - Show quoted text -
>
>
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Date: 07 Jun 2007 12:54:44
From: dvt
Subject: Re: Compact Crank Ring Differential
|
Bill wrote:
> russellseaton1@yahoo.com wrote:
>> On Jun 7, 12:57 am, Bill <b...@comcast.net> wrote:
>>> Johnny Sunset wrote:
>>>> I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
>>>> wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
>>>> and pins on the large chainring) but otherwise acceptable.
>>> If you were running a gear like that just what the hell did you have in
>>> the rear? 73/?? seems way unlikely.
>>> Bill Baka
>> 406mm tires are about 16-18" or so in diameter. I forget if 406 tires
>> are closer to 16" or 18". 73x13 with 406 gets you about 100 gear
>> inches. 52x28 gets you about 33 gear inches. Equivalent of a
>> sensibly geared compact double crankset today. I think 406mm is used
>> by Moulton bikes and foldable bikes. Bike Friday uses 406 I think on
>> their touring models. 420 on their racy models.
> Got a picture? It sounds like the crank would be almost as big as the
> tires and you would have a ground clearance problem. I don't recall ever
> seeing something like that in either of my LBS's.
Now you've done it... Tom loves to post links to pictures of his
bikes/trikes... check the archives. I'm 99.9% sure he's talking about a
recumbent of some sort.
--
Dave
dvt at psu dot edu
Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)
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Date: 07 Jun 2007 17:13:51
From: Bill
Subject: Re: Compact Crank Ring Differential
|
dvt wrote:
> Bill wrote:
>> russellseaton1@yahoo.com wrote:
>
>>> 406mm tires are about 16-18" or so in diameter. I forget if 406 tires
>>> are closer to 16" or 18". 73x13 with 406 gets you about 100 gear
>>> inches. 52x28 gets you about 33 gear inches. Equivalent of a
>>> sensibly geared compact double crankset today. I think 406mm is used
>>> by Moulton bikes and foldable bikes. Bike Friday uses 406 I think on
>>> their touring models. 420 on their racy models.
>
>> Got a picture? It sounds like the crank would be almost as big as the
>> tires and you would have a ground clearance problem. I don't recall
>> ever seeing something like that in either of my LBS's.
>
> Now you've done it... Tom loves to post links to pictures of his
> bikes/trikes... check the archives. I'm 99.9% sure he's talking about a
> recumbent of some sort.
>
I think that is likely the case, but it would still make for a good
conversation starter, hopefully with a babe.
Bill Baka
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Date: 07 Jun 2007 08:45:54
From: russellseaton1@yahoo.com
Subject: Re: Compact Crank Ring Differential
|
On Jun 6, 9:44 pm, A Muzi <a...@yellowjersey.org > wrote:
> > A Muzi <a...@yellowjersey.org> wrote:
> >> Ask any bike mechanic and you'll find the greater bulk of bicycles with
> >> multiple gearing are ridden in high gear until the small cog wears out.
> >> For every new bike changed to lower gearing we are asked a dozen times
> >> for higher ratios. I doubt we are unique in that and it is not at all a
> >> recent trend.
> Doug Taylor wrote:
> > What is a recent trend, however, is the popularity and marketing of
> > 110mm BCD compact cranks, and wide cassettes starting with an 11 and
> > ending with between 25 - 28 teeth.
>
> > When manufacturers such as FSA and IRD started heavily marketing
> > "neo-compact" a few years back, virtually all cassettes sold which
> > started an 11 ended with a 21 or 23. If a compact crank user wanted
> > their cake and eat it - to regain their high gear ( lost when
> > swapping a 50 tooth ring for the 53, but keeping a cassette which
> > started with 12) and at the same time having a low gear with a cog of
> > 25-28 (which is WHY they switched to compact in the first place) -
> > they had the choice of buying individual cogs and cobbing together
> > their own cassette (which Harris Cyclery does with their Shimano 9
> > speed cassette called "High and Wide") or, as I actually did, buying
> > both an Ultegra 11-23 AND a 12-27 on e-bay, and swapping cogs.
>
> > IRD started was early on the bandwagon, selling 11-25 and 11-28
> > "compact friendly" cassettes for 9 and 10 speed 3 years ago (not to
> > mention being the first to come out with a compact specific front
> > derailleur). SRAM came out with an 11-26 10 speed last year with
> > their new groupo, and this year Campy sells an 11-25 10 speed. But
> > you STILL can't find a wide Shimano cassette 9 or 10 speed (except the
> > Harris Cyclery "High and Wide").
>
> > When will Shimano jump on this marketing bandwagon?
>
> > Here is how I see it: millions of aging baby boomers, way too image
> > (and weight weenie) conscious to switch to triples, frothing at the
> > mouth and ready to blow mega cash on compact (that would be me, for
> > example). Not to mention female and junior racers who really can't
> > push the same gears as their male counterparts. Or male pros racing
> > up huge inclines.
>
> I believe the Shimano IG-7 (11~28, now others) has been around since
> 1994 or so. This is not a new concept, I can't explain or defend other
> trends mentioned.
Isn't the mid 1990s when the micro compact mountain bike crankset was
developed? 94/58 mm bcd instead of the standard compact 110/74 mm bcd
crankset. I think the 94/58 cranks came with 44-32-22 rings. 110/74
came with 48-36-24 rings. So the 11-28 cassette paired with the
44-32-22 gave the exact same highs and about the same lows as the
48-36-24 paired with a 12-28. Have to keep that high gear the same.
I guess the advantages of the smaller bcd and smaller cassette were a
couple grams weight savings and the ability to ride over bigger logs
without hitting the chainrings on the wood.
>
> --
> Andrew Muziwww.yellowjersey.org
> Open every day since 1 April, 1971- Hide quoted text -
>
> - Show quoted text -
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Date: 06 Jun 2007 22:23:04
From: Johnny Sunset
Subject: Re: Compact Crank Ring Differential
|
On Jun 4, 10:38 am, VeloJon wrote:
> According to Cyclingnews, several Giro riders were running 52/34 chain
> rings for the big climbs. I thought the conventional wisdom was that
> a 16-tooth differential between the 2 rings was the max for shifting
> smoothness on the front der. Before I go and try a 52/34 combo,
> opinions please?
I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
and pins on the large chainring) but otherwise acceptable.
--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful
|
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Date: 07 Jun 2007 05:57:51
From: Bill
Subject: Re: Compact Crank Ring Differential
|
Johnny Sunset wrote:
> On Jun 4, 10:38 am, VeloJon wrote:
>> According to Cyclingnews, several Giro riders were running 52/34 chain
>> rings for the big climbs. I thought the conventional wisdom was that
>> a 16-tooth differential between the 2 rings was the max for shifting
>> smoothness on the front der. Before I go and try a 52/34 combo,
>> opinions please?
>
> I used to run a 73/52 double on a bicycle with an ISO 406-mm drive
> wheel. Shifting with a Shimano RSX road derailleur was slow (no ramps
> and pins on the large chainring) but otherwise acceptable.
If you were running a gear like that just what the hell did you have in
the rear? 73/?? seems way unlikely.
Bill Baka
>
> --
> Tom Sherman - Holstein-Friesland Bovinia
> The weather is here, wish you were beautiful
>
>
>
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Date: 06 Jun 2007 22:16:51
From: Johnny Sunset
Subject: Re: Compact Crank Ring Differential
|
On Jun 4, 11:09 pm, A Muzi of Yellow Jersey wrote:
> > VeloJon wrote:
> >> According to Cyclingnews, several Giro riders were running 52/34 chain
> >> rings for the big climbs. I thought the conventional wisdom was that
> >> a 16-tooth differential between the 2 rings was the max for shifting
> >> smoothness on the front der. Before I go and try a 52/34 combo,
> >> opinions please?
> russellseat...@yahoo.com wrote:
> > I've used a 48-30 ring combination with a standard double front
> > derailleur. It shifted badly. But I did not shift it too often. A
> > 46-30 with a compact front derailleur works OK. Again, I don't really
> > shift it too often. I've never figured out why people/companies seem
> > to love the 50-34 combination. And now you want to go with a 52-34?
> > Shimano makes a 12-25 and 12-27 cassette in 9 and 10 speed.
> > Campagnolo makes a 12-25 cassette in 10 speed. One would think you
> > could get a more than high enough gear with a 50x12 and a low enough
> > with a 34x27 or 34x25. But you need a high of 52x12 AND a low of
> > 34x25 or 34x27? How is it that you have the strength to spin out a
> > 52x12 but don't have the power to climb in anything harder than a
> > 34x25 or 34x27?
>
> Just because.
>
> I remember Nishiki Internationals with a then-new 34t low gear
> freewheel. Our friend Peter Davis in Champaign IL...
Bought an ATB from Peter's shop some years back (but actually dealt
with Fritz for the purchase).
> sold a ton of them -
> on the prairie, where the Interstate overpass is the highest point.
The hilliest ride in Champaign County is south out of Philo (Center of
the Universe) on 1700E, then on to Block on 600E, since it crosses
Yankee Ridge.
> No rider can be wrong about his own opinion. Doesn't have to be logical.
Champaign County may be flat, but it is windy, especially in the
spring before the corn is tall enough to provide a windbreak. On a
Saturday morning ride in April, we went from Meadowbrook to Tolono at
7-8 mph into the southerly wind, and then returned at near 30 mph. Low
gears are very helpful in these situations.
--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful
|
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Date: 06 Jun 2007 15:51:46
From: russellseaton1@yahoo.com
Subject: Re: Compact Crank Ring Differential
|
On Jun 6, 1:57 pm, Michael Press <rub...@pacbell.net > wrote:
> In article <f46bvc$15v...@f04n12.cac.psu.edu>,
>
>
>
>
>
> dvt <dvt+use...@psu.edu> wrote:
> > Doug Taylor wrote:
> > > What is a recent trend, however, is the popularity and marketing of
> > > 110mm BCD compact cranks, and wide cassettes starting with an 11 and
> > > ending with between 25 - 28 teeth.
>
> > Maybe I'm missing your point, but... I've had difficulty finding a wide
> > range cassette that *doesn't* start at 11 (i.e. 12-28, 12-32, etc). IRD
> > recently (2006?) released 12-28 cassettes in 9-speed, but I don't know
> > where you can get a 12-30, 12-32, or 12-34 cassette. Sheldon sells a
> > custom 13-30 cassette, but it's really expensive.
>
> > On the other hand, MTB cassettes in 7/8/9 speed have been available in
> > 11-28, 11-30, 11-32, 11-34 combinations for quite some time. I have an
> > 11-34 cassette that I sometimes run with a 34-48 crank for a really wide
> > range of gears at the expense of narrow gaps between gears. If a 12-32
> > or 12-34 had been available, I would have chosen narrower gaps at the
> > expense of a really high gear.
>
> Shimano still makes a 14-32 seven speed. I run it with
> a half-step gearing double chain-ring on a utility
> bicycle. Not a lot of range, but it has close steps.
> Fourteen different gears.
> .
>
> --
> Michael Press- Hide quoted text -
>
> - Show quoted text -
I use either a 14-32 or 12-28 7 speed Shimano cassette on my loaded
touring bike. 45-42-20 chainrings. Great half step gearing and super
low granny. Used to have a 34 cog I put on instead of the 32, but the
new frame's rear derailleur hanger won't allow the derailleur to clear
the 34. So I had to go back to the 32 cog. The 12-28 cassette is for
when I take the loaded touring bike on week long rides and ride
unloaded in a pack and might need a high gear of 45x12 (101") instead
of 45x14 (87").
|
| |
Date: 06 Jun 2007 13:05:15
From: Sheldon Brown
Subject: Re: Compact Crank Ring Differential
|
Someone wrote:
> According to Cyclingnews, several Giro riders were running 52/34 chain
> rings for the big climbs. I thought the conventional wisdom was that
> a 16-tooth differential between the 2 rings was the max for shifting
> smoothness on the front der. Before I go and try a 52/34 combo,
> opinions please?
I've been very happy withthe 50-28 double on my Hetchins. Running
with a 12-28 9-speed cassette in back.
Shifting the front takes a bit more care and skill than a stock setup,
but it's not that difficult to master.
The idea of this setup is that 99% of riding is done on the 50 tooth
ring, which is lined up so that it works with all 9 sprockets in
back. Makes for a super-simple shifting pattern.
The 28 chainring is reserved for the worst hills, I generally only
used it with the 2 or 3 biggest rear sprockets. When the hill would
get steep enough that I needed the little chainring, I didn't mind the
gap in the gearing.
Sheldon "Wide Range Double" Brown
+----------------------------------------------+
|
| |
Date: 06 Jun 2007 06:20:15
From:
Subject: Re: Compact Crank Ring Differential
|
On Jun 6, 8:28 am, Doug Taylor <dtay...@dreamscape.com > wrote:
> derailleur). SRAM came out with an 11-26 10 speed last year with
> their new groupo, and this year Campy sells an 11-25 10 speed. But
> you STILL can't find a wide Shimano cassette 9 or 10 speed (except the
> Harris Cyclery "High and Wide").
>
> When will Shimano jump on this marketing bandwagon?
You *can* buy an 11-25 from Shimano in the new 105 10 speed group, at
least. I know because I have one (which came in the clearly labled
Shimano box). That isn't to say that here in Pittsburgh I might not
like an 11-27 from time to time, but 25 is certainly better than 23.
Having the 11 is nice with the 50-34 compact.
|
| | |
Date: 06 Jun 2007 11:33:09
From: Doug Taylor
Subject: Re: Compact Crank Ring Differential
|
On Wed, 06 Jun 2007 06:20:15 -0700, pghfoodnospam@yahoo.com wrote:
>You *can* buy an 11-25 from Shimano in the new 105 10 speed group, at
>least. I know because I have one (which came in the clearly labled
>Shimano box).
Good for Shimano: they jumped on as well.
A year ago they didn't exist:
http://www.velonews.com/tech/report/articles/9882.0.html
Now we'll see if they upgrade to Ultegra and Dura Ace
|
| |
Date: 06 Jun 2007 03:27:31
From: Michael Press
Subject: Re: Compact Crank Ring Differential
|
In article
<1180971489.611858.308730@m36g2000hse.googlegroups.com >
,
VeloJon <jprestley@comcast.net > wrote:
> According to Cyclingnews, several Giro riders were running 52/34 chain
> rings for the big climbs. I thought the conventional wisdom was that
> a 16-tooth differential between the 2 rings was the max for shifting
> smoothness on the front der. Before I go and try a 52/34 combo,
> opinions please?
Put on a triple.
26/19 ~= 34/25
26/21 ~= 34/27
Then you can go 39-53 with a 13 tooth jump to the
granny gear, and run an 11-21 cassette with impunity.
Heck, use a 26-38-48 and the shifts between the middle
and big ring are like buttah; you will not hesitate to
shift between the middle and large rings. There is room
at the bottom for even lower gears with no penalty in
shifting or jumps in the cassette.
If you cannot turn a 39/23, get a third chain wheel.
39/23 is plenty low except for very steep extended
pitches. It is not worth the effort trying to squeeze
the last bit of utility out of a double chain ring. You
end up with a marginal system that only barely, if at
all, meets the goals.
I am kind to my knees and not strong yet run 38/21 up
long 6% grades.
--
Michael Press
|
| |
Date: 06 Jun 2007 02:58:36
From: Ozark Bicycle
Subject: Re: Compact Crank Ring Differential
|
On Jun 5, 9:47 pm, bdbafh <bdb...@gmail.com > wrote:
> On Jun 5, 3:10 pm, Wayne <waynesu...@yahoo.com> wrote:
>
>
>
>
>
> > On Jun 5, 11:32 am, Drew Saunders <d...@nospamme-stanford.edu> wrote:
>
> > > On Jun 4, 10:38 am, VeloJon <jprest...@comcast.net> wrote:
>
> > > > > According to Cyclingnews, several Giro riders were running 52/34 chain
> > > > > rings for the big climbs. I thought the conventional wisdom was that
> > > > > a 16-tooth differential between the 2 rings was the max for shifting
> > > > > smoothness on the front der. Before I go and try a 52/34 combo,
> > > > > opinions please?
>
> > > I know many folks don't like the "T" word, but you're entering the realm
> > > where a triple makes a whole lot more sense. I don't know what rear
> > > cassette you want to use, but most of the folks on this thread have been
> > > discussing a 12-25 or 12-27. With a 26-38-48 and and 11-21, you get
> > > about the same top gear as a 52/12, a lower bottom gear than a 34/27,
> > > and really really small jumps in the cassette, with easier shifting up
> > > front too. A 28-38-48 with an 11-23 gives even easier shifting up front
> > > and an even lower bottom gear (close to the 34-29 that some of the folks
> > > reportedly used in the Giro). Both setups are easily done with any
> > > 74/110 crank, and even possible with a 74/130 "Racing Triple" crank.
>
> > > Sorry, I'm suggesting practical gearing, I should know better...
>
> > > Drew
>
> > > --
> > > Drew W. Saunders
>
> > > dru (at) stanford (dot) eee dee you
>
> > Amen - or 30/40/50 with 12-25 or so rear
>
> Or even a 30/39/53 (Shimano Dura Ace 7703 Triple Crank)
> What could be more simple than having your standard 53/39 and a 30T
> bailout ring up front?
>
> Yes, a cloaking device to make it appear to be a double would be nice
> but pricey.
>
I suspect there is a market for a "clear plastic" inner ring. However
short it's service life, some people would line up to buy 'em.
"Image is everything."
|
| | |
Date: 06 Jun 2007 03:13:30
From: Bill
Subject: Re: Compact Crank Ring Differential
|
Ozark Bicycle wrote:
> On Jun 5, 9:47 pm, bdbafh <bdb...@gmail.com> wrote:
>> On Jun 5, 3:10 pm, Wayne <waynesu...@yahoo.com> wrote:
>>
Snipped somebody.
>> Or even a 30/39/53 (Shimano Dura Ace 7703 Triple Crank)
>> What could be more simple than having your standard 53/39 and a 30T
>> bailout ring up front?
>>
>> Yes, a cloaking device to make it appear to be a double would be nice
>> but pricey.
What's the problem with a third ring? Sometimes (well, most times) I get
lazy and just want to spin a granny gear up a hill. Why not?
>>
>
> I suspect there is a market for a "clear plastic" inner ring. However
> short it's service life, some people would line up to buy 'em.
>
> "Image is everything."
>
Another Lance imitator?
Bill Baka
|
| |
Date: 06 Jun 2007 02:47:36
From: bdbafh
Subject: Re: Compact Crank Ring Differential
|
On Jun 5, 3:10 pm, Wayne <waynesu...@yahoo.com > wrote:
> On Jun 5, 11:32 am, Drew Saunders <d...@nospamme-stanford.edu> wrote:
>
>
>
> > On Jun 4, 10:38 am, VeloJon <jprest...@comcast.net> wrote:
>
> > > > According to Cyclingnews, several Giro riders were running 52/34 chain
> > > > rings for the big climbs. I thought the conventional wisdom was that
> > > > a 16-tooth differential between the 2 rings was the max for shifting
> > > > smoothness on the front der. Before I go and try a 52/34 combo,
> > > > opinions please?
>
> > I know many folks don't like the "T" word, but you're entering the realm
> > where a triple makes a whole lot more sense. I don't know what rear
> > cassette you want to use, but most of the folks on this thread have been
> > discussing a 12-25 or 12-27. With a 26-38-48 and and 11-21, you get
> > about the same top gear as a 52/12, a lower bottom gear than a 34/27,
> > and really really small jumps in the cassette, with easier shifting up
> > front too. A 28-38-48 with an 11-23 gives even easier shifting up front
> > and an even lower bottom gear (close to the 34-29 that some of the folks
> > reportedly used in the Giro). Both setups are easily done with any
> > 74/110 crank, and even possible with a 74/130 "Racing Triple" crank.
>
> > Sorry, I'm suggesting practical gearing, I should know better...
>
> > Drew
>
> > --
> > Drew W. Saunders
>
> > dru (at) stanford (dot) eee dee you
>
> Amen - or 30/40/50 with 12-25 or so rear
Or even a 30/39/53 (Shimano Dura Ace 7703 Triple Crank)
What could be more simple than having your standard 53/39 and a 30T
bailout ring up front?
Yes, a cloaking device to make it appear to be a double would be nice
but pricey.
-bdbafh
|
| |
Date: 05 Jun 2007 12:10:52
From: Wayne
Subject: Re: Compact Crank Ring Differential
|
On Jun 5, 11:32 am, Drew Saunders <d...@nospamme-stanford.edu > wrote:
> On Jun 4, 10:38 am, VeloJon <jprest...@comcast.net> wrote:
>
> > > According to Cyclingnews, several Giro riders were running 52/34 chain
> > > rings for the big climbs. I thought the conventional wisdom was that
> > > a 16-tooth differential between the 2 rings was the max for shifting
> > > smoothness on the front der. Before I go and try a 52/34 combo,
> > > opinions please?
>
> I know many folks don't like the "T" word, but you're entering the realm
> where a triple makes a whole lot more sense. I don't know what rear
> cassette you want to use, but most of the folks on this thread have been
> discussing a 12-25 or 12-27. With a 26-38-48 and and 11-21, you get
> about the same top gear as a 52/12, a lower bottom gear than a 34/27,
> and really really small jumps in the cassette, with easier shifting up
> front too. A 28-38-48 with an 11-23 gives even easier shifting up front
> and an even lower bottom gear (close to the 34-29 that some of the folks
> reportedly used in the Giro). Both setups are easily done with any
> 74/110 crank, and even possible with a 74/130 "Racing Triple" crank.
>
> Sorry, I'm suggesting practical gearing, I should know better...
>
> Drew
>
> --
> Drew W. Saunders
>
> dru (at) stanford (dot) eee dee you
Amen - or 30/40/50 with 12-25 or so rear
|
| |
Date: 05 Jun 2007 05:26:50
From: Qui si parla Campagnolo
Subject: Re: Compact Crank Ring Differential
|
On Jun 4, 9:38 am, VeloJon <jprest...@comcast.net > wrote:
> According to Cyclingnews, several Giro riders were running 52/34 chain
> rings for the big climbs. I thought the conventional wisdom was that
> a 16-tooth differential between the 2 rings was the max for shifting
> smoothness on the front der. Before I go and try a 52/34 combo,
> opinions please?
It works fine and if ya must, get a 'compact' or triple FD..but I have
installed many 52(3)/34 systems and they work fine. Probably will need
a third eye type chainwatcher..steep angle from the 52(3) to the
34..but otherwise it works fine, particularly with Campagnolo. Still
OK with shimano altho not as clean.
|
| |
Date: 04 Jun 2007 20:28:26
From: Ron Ruff
Subject: Re: Compact Crank Ring Differential
|
On Jun 4, 9:38 am, VeloJon <jprest...@comcast.net > wrote:
> Before I go and try a 52/34 combo,
> opinions please?
I don't know what you are used to, but I don't even like the 34/50 for
other reasons... too much rear shifting when the front is shifted, and
too little overlap. I run a 34/48 with a 9spd 12-26 and don't miss the
high gears when I'm tucked and coasting at 55mph. If you are running a
very wide range cassette the overlap is less of an issue, though.
|
| |
Date: 04 Jun 2007 18:18:49
From: russellseaton1@yahoo.com
Subject: Re: Compact Crank Ring Differential
|
On Jun 4, 10:38 am, VeloJon <jprest...@comcast.net > wrote:
> According to Cyclingnews, several Giro riders were running 52/34 chain
> rings for the big climbs. I thought the conventional wisdom was that
> a 16-tooth differential between the 2 rings was the max for shifting
> smoothness on the front der. Before I go and try a 52/34 combo,
> opinions please?
I've used a 48-30 ring combination with a standard double front
derailleur. It shifted badly. But I did not shift it too often. A
46-30 with a compact front derailleur works OK. Again, I don't really
shift it too often. I've never figured out why people/companies seem
to love the 50-34 combination. And now you want to go with a 52-34?
Shimano makes a 12-25 and 12-27 cassette in 9 and 10 speed.
Campagnolo makes a 12-25 cassette in 10 speed. One would think you
could get a more than high enough gear with a 50x12 and a low enough
with a 34x27 or 34x25. But you need a high of 52x12 AND a low of
34x25 or 34x27? How is it that you have the strength to spin out a
52x12 but don't have the power to climb in anything harder than a
34x25 or 34x27?
|
| | |
Date: 05 Jun 2007 09:32:46
From: Drew Saunders
Subject: Re: Compact Crank Ring Differential
|
On Jun 4, 10:38 am, VeloJon <jprest...@comcast.net > wrote:
> > According to Cyclingnews, several Giro riders were running 52/34 chain
> > rings for the big climbs. I thought the conventional wisdom was that
> > a 16-tooth differential between the 2 rings was the max for shifting
> > smoothness on the front der. Before I go and try a 52/34 combo,
> > opinions please?
I know many folks don't like the "T" word, but you're entering the realm
where a triple makes a whole lot more sense. I don't know what rear
cassette you want to use, but most of the folks on this thread have been
discussing a 12-25 or 12-27. With a 26-38-48 and and 11-21, you get
about the same top gear as a 52/12, a lower bottom gear than a 34/27,
and really really small jumps in the cassette, with easier shifting up
front too. A 28-38-48 with an 11-23 gives even easier shifting up front
and an even lower bottom gear (close to the 34-29 that some of the folks
reportedly used in the Giro). Both setups are easily done with any
74/110 crank, and even possible with a 74/130 "Racing Triple" crank.
Sorry, I'm suggesting practical gearing, I should know better...
Drew
--
Drew W. Saunders
dru (at) stanford (dot) eee dee you
|
| | | |
Date: 06 Jun 2007 03:39:16
From: Michael Press
Subject: Re: Compact Crank Ring Differential
|
In article
<dru-8F9A60.09324605062007@news.stanford.edu >,
Drew Saunders <dru@nospamme-stanford.edu > wrote:
> On Jun 4, 10:38 am, VeloJon <jprest...@comcast.net> wrote:
> > > According to Cyclingnews, several Giro riders were running 52/34 chain
> > > rings for the big climbs. I thought the conventional wisdom was that
> > > a 16-tooth differential between the 2 rings was the max for shifting
> > > smoothness on the front der. Before I go and try a 52/34 combo,
> > > opinions please?
>
> I know many folks don't like the "T" word, but you're entering the realm
> where a triple makes a whole lot more sense. I don't know what rear
> cassette you want to use, but most of the folks on this thread have been
> discussing a 12-25 or 12-27. With a 26-38-48 and and 11-21, you get
> about the same top gear as a 52/12, a lower bottom gear than a 34/27,
> and really really small jumps in the cassette, with easier shifting up
> front too. A 28-38-48 with an 11-23 gives even easier shifting up front
> and an even lower bottom gear (close to the 34-29 that some of the folks
> reportedly used in the Giro). Both setups are easily done with any
> 74/110 crank, and even possible with a 74/130 "Racing Triple" crank.
>
> Sorry, I'm suggesting practical gearing, I should know better...
I recently composed an article with the same notions,
and I should know better too. The saving grace is that
when I post nonsense, I can depend on a response.
--
Michael Press
|
| | |
Date: 05 Jun 2007 12:09:53
From: Doug Taylor
Subject: Re: Compact Crank Ring Differential
|
On Mon, 04 Jun 2007 18:18:49 -0700, "russellseaton1@yahoo.com"
<russellseaton1@yahoo.com > wrote:
> I've never figured out why people/companies seem
>to love the 50-34 combination.
Because it is versatile?
> How is it that you have the strength to spin out a
>52x12 but don't have the power to climb in anything harder than a
>34x25 or 34x27?
Old age and ego.
If you ride in a pack of riders who all have 53:12 as a high, you WILL
find numerous situations, downhill, where a 50:12 just doesn't cut it
(you might not spin OUT, per se, but you might well spin too MUCH).
And you don't have to be Godzilla for this to be the case.
Meanwhile, going up, you will NEED the low-low gears (I have a 34:28,
thank you very much) in order not blow up 56 year old knees and quads.
I live in a hilly area where 34:28 is not even all that wimpy. Being
able to climb even the most arduous pitches seated is a great quad
saver for a Master Fatty. You can stand and grind if you want - but
you don't HAVE to.
|
| | |
Date: 04 Jun 2007 23:09:20
From: A Muzi
Subject: Re: Compact Crank Ring Differential
|
> VeloJon <jprest...@comcast.net> wrote:
>> According to Cyclingnews, several Giro riders were running 52/34 chain
>> rings for the big climbs. I thought the conventional wisdom was that
>> a 16-tooth differential between the 2 rings was the max for shifting
>> smoothness on the front der. Before I go and try a 52/34 combo,
>> opinions please?
russellseaton1@yahoo.com wrote:
> I've used a 48-30 ring combination with a standard double front
> derailleur. It shifted badly. But I did not shift it too often. A
> 46-30 with a compact front derailleur works OK. Again, I don't really
> shift it too often. I've never figured out why people/companies seem
> to love the 50-34 combination. And now you want to go with a 52-34?
> Shimano makes a 12-25 and 12-27 cassette in 9 and 10 speed.
> Campagnolo makes a 12-25 cassette in 10 speed. One would think you
> could get a more than high enough gear with a 50x12 and a low enough
> with a 34x27 or 34x25. But you need a high of 52x12 AND a low of
> 34x25 or 34x27? How is it that you have the strength to spin out a
> 52x12 but don't have the power to climb in anything harder than a
> 34x25 or 34x27?
Just because.
I remember Nishiki Internationals with a then-new 34t low gear
freewheel. Our friend Peter Davis in Champaign IL sold a ton of them -
on the prairie, where the Interstate overpass is the highest point.
No rider can be wrong about his own opinion. Doesn't have to be logical.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
|
| | | |
Date: 05 Jun 2007 09:30:47
From: RS
Subject: Re: Compact Crank Ring Differential
|
In article <1369ofmpf6uuv1b@corp.supernews.com >,
am@yellowjersey.org says...
>
>
>> VeloJon <jprest...@comcast.net> wrote:
>>> According to Cyclingnews, several Giro riders were running 52/34
chain
>>> rings for the big climbs. I thought the conventional wisdom was
that
>>> a 16-tooth differential between the 2 rings was the max for shifting
>>> smoothness on the front der. Before I go and try a 52/34 combo,
>>> opinions please?
>
>russellseaton1@yahoo.com wrote:
>> I've used a 48-30 ring combination with a standard double front
>> derailleur. It shifted badly. But I did not shift it too often. A
>> 46-30 with a compact front derailleur works OK. Again, I don't really
>> shift it too often. I've never figured out why people/companies
seem
>> to love the 50-34 combination. And now you want to go with a 52-
34?
>> Shimano makes a 12-25 and 12-27 cassette in 9 and 10 speed.
>> Campagnolo makes a 12-25 cassette in 10 speed. One would think
you
>> could get a more than high enough gear with a 50x12 and a low
enough
>> with a 34x27 or 34x25. But you need a high of 52x12 AND a low of
>> 34x25 or 34x27? How is it that you have the strength to spin out a
>> 52x12 but don't have the power to climb in anything harder than a
>> 34x25 or 34x27?
>
>Just because.
>
>I remember Nishiki Internationals with a then-new 34t low gear
>freewheel. Our friend Peter Davis in Champaign IL sold a ton of them -
>on the prairie, where the Interstate overpass is the highest point.
>
>No rider can be wrong about his own opinion. Doesn't have to be
logical.
>--
>Andrew Muzi
>www.yellowjersey.org
>Open every day since 1 April, 1971
It would be very helpful for Shimano to make 11-27 cassettes in Ultegra
quality for reasonable price and weight, and in 9 and 10 speed. 50-11 is
higher then 53-12 and sometimes needed. 34-27 is nice if you live
where there are steep hills and/or or just dog tired going up your own
hill. Where're not all 23 both in age and BMI. ;)
|
| | | | |
Date: 05 Jun 2007 10:05:29
From: Dane Buson
Subject: Re: Compact Crank Ring Differential
|
RS <r_schiller@comcast.net > wrote:
>
> It would be very helpful for Shimano to make 11-27 cassettes in Ultegra
> quality for reasonable price and weight, and in 9 and 10 speed.
That would certainly be nice. I've been using the 11-26 cassettes from
SRAM. I can't find any LX 12-32 cassettes to make 11-28's anymore. Are
they not being produced anymore?
--
Dane Buson - sigdane@unixbigots.org
All I know is what the words know, and dead things, and that
makes a handsome little sum, with a beginning and a middle and
an end, as in the well-built phrase and the long sonata of the dead.
-- Samuel Beckett
|
| | | | | |
Date: 05 Jun 2007 12:51:22
From: RS
Subject: Re: Compact Crank Ring Differential
|
In article <pnhgj4-0f8.ln1@curare.zuvembi.homelinux.org >,
dane@unseen.edu says...
>
>
>RS <r_schiller@comcast.net> wrote:
>>
>> It would be very helpful for Shimano to make 11-27 cassettes in
Ultegra
>> quality for reasonable price and weight, and in 9 and 10 speed.
>
>That would certainly be nice. I've been using the 11-26 cassettes from
>SRAM. I can't find any LX 12-32 cassettes to make 11-28's anymore.
Are
>they not being produced anymore?
>
>--
>Dane Buson - sigdane@unixbigots.org
>All I know is what the words know, and dead things, and that
>makes a handsome little sum, with a beginning and a middle and
>an end, as in the well-built phrase and the long sonata of the dead.
> -- Samuel Beckett
My commuter has a 50x34 and a sram 11-28 on the back, though older
8speed setup. Works fine and is a nice wide range. I use road derailleurs
on the back, currently a mid-cage Ultegra 6500 and it works fine though
suspect it would also work with a short-cage derailleur though beyond the
published specifications.
|
| | |
Date: 05 Jun 2007 03:46:52
From: Steve Gravrock
Subject: Re: Compact Crank Ring Differential
|
On 2007-06-05, russellseaton1@yahoo.com <russellseaton1@yahoo.com > wrote:
> How is it that you have the strength to spin out a
> 52x12 but don't have the power to climb in anything harder than a
> 34x25 or 34x27?
On the contrary, folks who need a low bottom gear very often have more
use for a high top gear as well. The 52x12 is for going down the hills
that you need the 34x25 for. Or in my case, the hills that I need the
30x30 for. I suppose you could always coast down the steeper hills, but
pedaling down them is sometimes useful and often fun.
My morning commute involves a left turn off of a 5 lane street in
downhill 35 MPH traffic. The hill isn't steep enough for me to reach
that speed on gravity alone, and being able to help things along without
spinning like a madman is very nice.
|
| | | |
Date: 05 Jun 2007 20:41:44
From: David L. Johnson
Subject: Re: Compact Crank Ring Differential
|
Steve Gravrock wrote:
> On 2007-06-05, russellseaton1@yahoo.com <russellseaton1@yahoo.com> wrote:
>
>> How is it that you have the strength to spin out a
>> 52x12 but don't have the power to climb in anything harder than a
>> 34x25 or 34x27?
>
> On the contrary, folks who need a low bottom gear very often have more
> use for a high top gear as well. The 52x12 is for going down the hills
> that you need the 34x25 for. Or in my case, the hills that I need the
> 30x30 for. I suppose you could always coast down the steeper hills, but
> pedaling down them is sometimes useful and often fun.
If that pulls your chain, fine, but frankly "need" and huge gears don't
make much sense to me, unless you need to win that downhill sprint to
become a stage winner on the Tour.
No one, and that means no one, can "spin" a 52/12 on the flats. Build
up to a good rpm in a sprint, maybe, if you are very strong, but spin
along the road? No. On downhills, I can usually beat most anyone I
ride with, and my top gear is a 46/12. I do that by knowing better how
to corner, and by having a better mass/frontal area ratio.
--
David L. Johnson
If all economists were laid end to end, they would not reach a
conclusion.
-- George Bernard Shaw
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| | | | |
Date: 06 Jun 2007 03:45:14
From: Steve Gravrock
Subject: Re: Compact Crank Ring Differential
|
On 2007-06-06, David L. Johnson <david.johnson@lehigh.edu > wrote:
> Steve Gravrock wrote:
>> On 2007-06-05, russellseaton1@yahoo.com <russellseaton1@yahoo.com> wrote:
>>
>>> How is it that you have the strength to spin out a
>>> 52x12 but don't have the power to climb in anything harder than a
>>> 34x25 or 34x27?
>>
>> On the contrary, folks who need a low bottom gear very often have more
>> use for a high top gear as well. The 52x12 is for going down the hills
>> that you need the 34x25 for. Or in my case, the hills that I need the
>> 30x30 for. I suppose you could always coast down the steeper hills, but
>> pedaling down them is sometimes useful and often fun.
>
> If that pulls your chain, fine, but frankly "need" and huge gears don't
> make much sense to me, unless you need to win that downhill sprint to
> become a stage winner on the Tour.
In the situation I described, which you snipped, I'd need to spin at
close to 120 RPM with your top gear in order to keep up with traffic. I
can do that, but not comfortably and not for very long. While not being
able to keep up with traffic isn't the end of the world, it sometimes
means missing a lane change and thus the left turn. That's not a huge
deal -- I can always go around the block or turn into a pedestrian at
the intersection -- but it's nice to be able to avoid it. That happened
often enough when my top gear was a 44/12 that having a 52 tooth ring
was a refreshing change.
Necessary? No. I got by without it in the past and could do so again.
Makes sense for me? Absolutely. The fact that it doesn't make sense for
you in the sort of riding you do doesn't change that.
|
| | | | | |
Date: 06 Jun 2007 03:46:53
From: Steve Gravrock
Subject: Re: Compact Crank Ring Differential
|
On 2007-06-06, Steve Gravrock <usenet@sdg.users.panix.com > wrote:
> That happened
> often enough when my top gear was a 44/12 that having a 52 tooth ring
> was a refreshing change.
By 44/12 I mean 44/14, for what difference it makes.
|
| | | | |
Date: 05 Jun 2007 21:53:58
From: A Muzi
Subject: Re: Compact Crank Ring Differential
|
>> russellseaton1@yahoo.com <russellseaton1@yahoo.com> wrote:
>>> How is it that you have the strength to spin out a
>>> 52x12 but don't have the power to climb in anything harder than a
>>> 34x25 or 34x27?
> Steve Gravrock wrote:
>> On the contrary, folks who need a low bottom gear very often have more
>> use for a high top gear as well. The 52x12 is for going down the hills
>> that you need the 34x25 for. Or in my case, the hills that I need the
>> 30x30 for. I suppose you could always coast down the steeper hills, but
>> pedaling down them is sometimes useful and often fun.
David L. Johnson wrote:
> If that pulls your chain, fine, but frankly "need" and huge gears don't
> make much sense to me, unless you need to win that downhill sprint to
> become a stage winner on the Tour.
>
> No one, and that means no one, can "spin" a 52/12 on the flats. Build
> up to a good rpm in a sprint, maybe, if you are very strong, but spin
> along the road? No. On downhills, I can usually beat most anyone I
> ride with, and my top gear is a 46/12. I do that by knowing better how
> to corner, and by having a better mass/frontal area ratio.
Maybe change Steve's 'need' to 'prefer' or 'desire'?
No rider is wrong about his opinion. Despite my own opinion, which seems
similar to yours on gearing, others can and do differ. Greatly. Note
Carl happily rides at a cadence which may seem odd to us but he happily
rides every day. 'YMMV' has never been more apt.
Ask any bike mechanic and you'll find the greater bulk of bicycles with
multiple gearing are ridden in high gear until the small cog wears out.
For every new bike changed to lower gearing we are asked a dozen times
for higher ratios. I doubt we are unique in that and it is not at all a
recent trend.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
|
| | | | | |
Date: 07 Jun 2007 20:10:14
From: John Thompson
Subject: Re: Compact Crank Ring Differential
|
On 2007-06-06, A Muzi <am@yellowjersey.org > wrote:
> Ask any bike mechanic and you'll find the greater bulk of bicycles with
> multiple gearing are ridden in high gear until the small cog wears out.
> For every new bike changed to lower gearing we are asked a dozen times
> for higher ratios. I doubt we are unique in that and it is not at all a
> recent trend.
I'm sure you're right, but speaking for myself I have been converting
all my bikes to smaller chainrings and lower high gears. The biggest
ring I now run is 50T, on my tandem, with a 14-30 freewheel in the back.
The large rings on my other bikes range from 43T to 48T.
FWIW, I don't get dropped on group rides.
--
John (john@os2.dhs.org)
|
| | | | | |
Date: 06 Jun 2007 08:28:14
From: Doug Taylor
Subject: Re: Compact Crank Ring Differential
|
On Tue, 05 Jun 2007 21:53:58 -0500, A Muzi <am@yellowjersey.org >
wrote:
>Ask any bike mechanic and you'll find the greater bulk of bicycles with
>multiple gearing are ridden in high gear until the small cog wears out.
>For every new bike changed to lower gearing we are asked a dozen times
>for higher ratios. I doubt we are unique in that and it is not at all a
>recent trend.
What is a recent trend, however, is the popularity and marketing of
110mm BCD compact cranks, and wide cassettes starting with an 11 and
ending with between 25 - 28 teeth.
When manufacturers such as FSA and IRD started heavily marketing
"neo-compact" a few years back, virtually all cassettes sold which
started an 11 ended with a 21 or 23. If a compact crank user wanted
their cake and eat it - to regain their high gear ( lost when
swapping a 50 tooth ring for the 53, but keeping a cassette which
started with 12) and at the same time having a low gear with a cog of
25-28 (which is WHY they switched to compact in the first place) -
they had the choice of buying individual cogs and cobbing together
their own cassette (which Harris Cyclery does with their Shimano 9
speed cassette called "High and Wide") or, as I actually did, buying
both an Ultegra 11-23 AND a 12-27 on e-bay, and swapping cogs.
IRD started was early on the bandwagon, selling 11-25 and 11-28
"compact friendly" cassettes for 9 and 10 speed 3 years ago (not to
mention being the first to come out with a compact specific front
derailleur). SRAM came out with an 11-26 10 speed last year with
their new groupo, and this year Campy sells an 11-25 10 speed. But
you STILL can't find a wide Shimano cassette 9 or 10 speed (except the
Harris Cyclery "High and Wide").
When will Shimano jump on this marketing bandwagon?
Here is how I see it: millions of aging baby boomers, way too image
(and weight weenie) conscious to switch to triples, frothing at the
mouth and ready to blow mega cash on compact (that would be me, for
example). Not to mention female and junior racers who really can't
push the same gears as their male counterparts. Or male pros racing
up huge inclines.
|
| | | | | | |
Date: 06 Jun 2007 21:44:51
From: A Muzi
Subject: Re: Compact Crank Ring Differential
|
> A Muzi <am@yellowjersey.org> wrote:
>> Ask any bike mechanic and you'll find the greater bulk of bicycles with
>> multiple gearing are ridden in high gear until the small cog wears out.
>> For every new bike changed to lower gearing we are asked a dozen times
>> for higher ratios. I doubt we are unique in that and it is not at all a
>> recent trend.
Doug Taylor wrote:
> What is a recent trend, however, is the popularity and marketing of
> 110mm BCD compact cranks, and wide cassettes starting with an 11 and
> ending with between 25 - 28 teeth.
>
> When manufacturers such as FSA and IRD started heavily marketing
> "neo-compact" a few years back, virtually all cassettes sold which
> started an 11 ended with a 21 or 23. If a compact crank user wanted
> their cake and eat it - to regain their high gear ( lost when
> swapping a 50 tooth ring for the 53, but keeping a cassette which
> started with 12) and at the same time having a low gear with a cog of
> 25-28 (which is WHY they switched to compact in the first place) -
> they had the choice of buying individual cogs and cobbing together
> their own cassette (which Harris Cyclery does with their Shimano 9
> speed cassette called "High and Wide") or, as I actually did, buying
> both an Ultegra 11-23 AND a 12-27 on e-bay, and swapping cogs.
>
> IRD started was early on the bandwagon, selling 11-25 and 11-28
> "compact friendly" cassettes for 9 and 10 speed 3 years ago (not to
> mention being the first to come out with a compact specific front
> derailleur). SRAM came out with an 11-26 10 speed last year with
> their new groupo, and this year Campy sells an 11-25 10 speed. But
> you STILL can't find a wide Shimano cassette 9 or 10 speed (except the
> Harris Cyclery "High and Wide").
>
> When will Shimano jump on this marketing bandwagon?
>
> Here is how I see it: millions of aging baby boomers, way too image
> (and weight weenie) conscious to switch to triples, frothing at the
> mouth and ready to blow mega cash on compact (that would be me, for
> example). Not to mention female and junior racers who really can't
> push the same gears as their male counterparts. Or male pros racing
> up huge inclines.
I believe the Shimano IG-7 (11~28, now others) has been around since
1994 or so. This is not a new concept, I can't explain or defend other
trends mentioned.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
|
| | | | | | | |
Date: 07 Jun 2007 09:21:28
From: Doug Taylor
Subject: Re: Compact Crank Ring Differential
|
On Wed, 06 Jun 2007 21:44:51 -0500, A Muzi <am@yellowjersey.org >
wrote:
>I believe the Shimano IG-7 (11~28, now others) has been around since
>1994 or so. This is not a new concept, I can't explain or defend other
>trends mentioned.
One more time:
What is new is the heavy MARKETING of 110 bcd compact front cranks and
chainrings, commencing with FSA and IRD around 2002 or 2003, IIRC.
Before that, the normal usual spec. on most new bikes was 53/39.
As far as cassettes, I'm specifically addressing 9 and 10 speed, not
7, 8 or anything else.
IRD was the first manufacturer to sell 11-25 and 11-28 cassettes for 9
and 10 speed (except for Sheldon Brown's High and Wide) - which were
specifically marketed for people using compact rings.
In 2006, SRAM started selling an 11-26 cassette, marketed for compact.
Until 2007, Shimano and Campy did not sell cassettes for 9 and 10
speed which started with 11 and ended with 25, 26,27, or 28 (except
for Sheldon Brown's High and Wide), as confirmed by Lennard Zinn
http://www.velonews.com/tech/report/articles/9882.0.html
As an example of this marketing ( 2007 Campy):
"11-25 Sprocket sets. The 11-25 combination springs from a demand from
users for compact cranksets with a broader range of ratios, just as
suitable for the steepest climbs as for fast pedalable descents."
http://www.ppolnews.com/?id=82140&keys=campagnolo-differentiated-brakes
Does this make sense to anyone except me?
Guess not.
|
| | | | | | | | |
Date: 07 Jun 2007 11:27:58
From: dvt
Subject: Re: Compact Crank Ring Differential
|
Doug Taylor wrote:
> What is new is the heavy MARKETING of 110 bcd compact front cranks and
> chainrings, commencing with FSA and IRD around 2002 or 2003, IIRC.
>
> Before that, the normal usual spec. on most new bikes was 53/39.
>
> As far as cassettes, I'm specifically addressing 9 and 10 speed, not
> 7, 8 or anything else.
[snip]
> Does this make sense to anyone except me?
I got it now. Your earlier post said something different.
--
Dave
dvt at psu dot edu
Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)
|
| | | | | | |
Date: 06 Jun 2007 09:14:23
From: dvt
Subject: Re: Compact Crank Ring Differential
|
Doug Taylor wrote:
> What is a recent trend, however, is the popularity and marketing of
> 110mm BCD compact cranks, and wide cassettes starting with an 11 and
> ending with between 25 - 28 teeth.
Maybe I'm missing your point, but... I've had difficulty finding a wide
range cassette that *doesn't* start at 11 (i.e. 12-28, 12-32, etc). IRD
recently (2006?) released 12-28 cassettes in 9-speed, but I don't know
where you can get a 12-30, 12-32, or 12-34 cassette. Sheldon sells a
custom 13-30 cassette, but it's really expensive.
On the other hand, MTB cassettes in 7/8/9 speed have been available in
11-28, 11-30, 11-32, 11-34 combinations for quite some time. I have an
11-34 cassette that I sometimes run with a 34-48 crank for a really wide
range of gears at the expense of narrow gaps between gears. If a 12-32
or 12-34 had been available, I would have chosen narrower gaps at the
expense of a really high gear.
--
Dave
dvt at psu dot edu
Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)
|
| | | | | | | |
Date: 06 Jun 2007 18:57:35
From: Michael Press
Subject: Re: Compact Crank Ring Differential
|
In article <f46bvc$15vs$1@f04n12.cac.psu.edu >,
dvt <dvt+usenet@psu.edu > wrote:
> Doug Taylor wrote:
> > What is a recent trend, however, is the popularity and marketing of
> > 110mm BCD compact cranks, and wide cassettes starting with an 11 and
> > ending with between 25 - 28 teeth.
>
> Maybe I'm missing your point, but... I've had difficulty finding a wide
> range cassette that *doesn't* start at 11 (i.e. 12-28, 12-32, etc). IRD
> recently (2006?) released 12-28 cassettes in 9-speed, but I don't know
> where you can get a 12-30, 12-32, or 12-34 cassette. Sheldon sells a
> custom 13-30 cassette, but it's really expensive.
>
> On the other hand, MTB cassettes in 7/8/9 speed have been available in
> 11-28, 11-30, 11-32, 11-34 combinations for quite some time. I have an
> 11-34 cassette that I sometimes run with a 34-48 crank for a really wide
> range of gears at the expense of narrow gaps between gears. If a 12-32
> or 12-34 had been available, I would have chosen narrower gaps at the
> expense of a really high gear.
Shimano still makes a 14-32 seven speed. I run it with
a half-step gearing double chain-ring on a utility
bicycle. Not a lot of range, but it has close steps.
Fourteen different gears.
.
--
Michael Press
|
| | | | | | | |
Date: 06 Jun 2007 11:33:54
From: Doug Taylor
Subject: Re: Compact Crank Ring Differential
|
On Wed, 06 Jun 2007 09:14:23 -0400, dvt <dvt+usenet@psu.edu > wrote:
>Maybe I'm missing your point,
You did. Re-read the post.
|
| | | | | | | | |
Date: 06 Jun 2007 11:47:37
From: dvt
Subject: Re: Compact Crank Ring Differential
|
Doug Taylor wrote:
> On Wed, 06 Jun 2007 09:14:23 -0400, dvt <dvt+usenet@psu.edu> wrote:
>
>> Maybe I'm missing your point,
>
> You did. Re-read the post.
Sorry, I still don't get it. I've used 11-28 Shimano and aftermarket
cassettes in 8 and 9-speed configurations for several years. It's the
12-28 that was missing from the lineup, IMO.
Maybe you were talking about 7-speed? 8-speed bits have been available
for around 15 years, and I know that 8 spd 11-28 cassettes were
available for the past several years.
I've never seen an 11-25, so I'm with you on that one.
--
Dave
dvt at psu dot edu
Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)
|
| | | | | | | | | |
Date: 06 Jun 2007 15:30:39
From: Doug Taylor
Subject: Re: Compact Crank Ring Differential
|
On Wed, 06 Jun 2007 11:47:37 -0400, dvt <dvt+usenet@psu.edu > wrote:
>Doug Taylor wrote:
>> On Wed, 06 Jun 2007 09:14:23 -0400, dvt <dvt+usenet@psu.edu> wrote:
>>
>>> Maybe I'm missing your point,
>>
>> You did. Re-read the post.
>
>Sorry, I still don't get it.
Then either I can't write or you can't read.
|
| | | | | | | | | | |
Date: 06 Jun 2007 16:43:09
From: dvt
Subject: Re: Compact Crank Ring Differential
|
Doug Taylor wrote:
> On Wed, 06 Jun 2007 11:47:37 -0400, dvt <dvt+usenet@psu.edu> wrote:
>> Doug Taylor wrote:
>>> On Wed, 06 Jun 2007 09:14:23 -0400, dvt <dvt+usenet@psu.edu> wrote:
>> Sorry, I still don't get it.
> Then either I can't write or you can't read.
One more try... you said:
> ...a few years back, virtually all cassettes sold which
> started an 11 ended with a 21 or 23.
Shimano has offered 11-28 cassettes available in 7/8/9 speed for many
years. That seems to contradict what you said. Did I misread?
--
Dave
dvt at psu dot edu
|
| | | | | | | | | | | |
Date: 06 Jun 2007 20:53:07
From: Bill
Subject: Re: Compact Crank Ring Differential
|
dvt wrote:
> Doug Taylor wrote:
>> On Wed, 06 Jun 2007 11:47:37 -0400, dvt <dvt+usenet@psu.edu> wrote:
>>> Doug Taylor wrote:
>>>> On Wed, 06 Jun 2007 09:14:23 -0400, dvt <dvt+usenet@psu.edu> wrote:
>
>>> Sorry, I still don't get it.
>
>> Then either I can't write or you can't read.
>
> One more try... you said:
>
>> ...a few years back, virtually all cassettes sold which
>> started an 11 ended with a 21 or 23.
>
> Shimano has offered 11-28 cassettes available in 7/8/9 speed for many
> years. That seems to contradict what you said. Did I misread?
>
2 cents worth.
I have a 7 speed 11,13,15,18,21,24,28 that works for me. It is also the
one that has the silent clutch mechanism. I don't know who made it
though unless I want to take the wheel off and look.
2 cents off.
Bill Baka
|
| | | | |
Date: 05 Jun 2007 21:19:23
From: Barry
Subject: Re: Compact Crank Ring Differential
|
> No one, and that means no one, can "spin" a 52/12 on the flats. Build up to
> a good rpm in a sprint, maybe, if you are very strong, but spin along the
> road? No.
For what it's worth, a 52/12 with a cadence of 90 rpm is about 30.5 mph. A
cadence of 100 would be about 34 mph.
|
| | | | | |
Date: 06 Jun 2007 02:10:47
From: Bill
Subject: Re: Compact Crank Ring Differential
|
Barry wrote:
>> No one, and that means no one, can "spin" a 52/12 on the flats. Build up to
>> a good rpm in a sprint, maybe, if you are very strong, but spin along the
>> road? No.
>
> For what it's worth, a 52/12 with a cadence of 90 rpm is about 30.5 mph. A
> cadence of 100 would be about 34 mph.
>
>
Another for what it's worth is going downhill at 50 MPH on a mountain
bike with a 46/11 and trying to pedal, which just does not work. I
couldn't spin fast enough to even get the freewheel to engage. Maybe if
I put on my 58 front ring it would work but then the chain hangs up half
the time, so the 58 ring is just a decoration now.
Sometimes it makes sense to coast and enjoy the free speed.
Bill Baka
|
| | | | |
Date: 05 Jun 2007 20:53:08
From: John Forrest Tomlinson
Subject: Re: Compact Crank Ring Differential
|
On Tue, 05 Jun 2007 20:41:44 -0400, "David L. Johnson"
<david.johnson@lehigh.edu > wrote:
>If that pulls your chain, fine, but frankly "need" and huge gears don't
>make much sense to me, unless you need to win that downhill sprint to
>become a stage winner on the Tour.
So if a gear like 52x12 would help someone win a low level bike race,
that's not "need" since their livelihood or something doesn't depend
on it?
I've been in in two local/regional cycling events this year where not
having a 12 would be a significant disadvantage.
But we don't need it? How do you define need if not by failing at the
task at hand w/o something?
>No one, and that means no one, can "spin" a 52/12 on the flats. Build
>up to a good rpm in a sprint,
I'm not sure what you mean by spin, but in the early 1990s I did a
three or four mile time trial with a ripping tail wind and was
turning a 12 cog with 50 or 51 uncomfortably fast the whole time and
finished in the back quarter of the field. Tyler Hamilton and Kirk
Willett were first and second and I'm pretty sure they would have been
spinning 52x12. Willet at least had a much bigger gear that he used
the whole time apart from the first few seconds of the event. The even
was flat.
And I've been in races with very shallow grades like a percent or two
where we were spinning 12 frantically downhill. Not flat I guess.
--
JT
****************************
Remove "remove" to reply
Visit http://www.jt10000.com
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|
| | |
Date: 04 Jun 2007 21:33:56
From: John Forrest Tomlinson
Subject: Re: Compact Crank Ring Differential
|
On Mon, 04 Jun 2007 18:18:49 -0700, "russellseaton1@yahoo.com"
<russellseaton1@yahoo.com > wrote:
>How is it that you have the strength to spin out a
>52x12 but don't have the power to climb in anything harder than a
>34x25 or 34x27?
Big hills.
--
JT
****************************
Remove "remove" to reply
Visit http://www.jt10000.com
****************************
|
| |
Date: 04 Jun 2007 16:07:04
From: andresmuro@aol.com
Subject: Re: Compact Crank Ring Differential
|
On Jun 4, 9:38 am, VeloJon <jprest...@comcast.net > wrote:
> According to Cyclingnews, several Giro riders were running 52/34 chain
> rings for the big climbs. I thought the conventional wisdom was that
> a 16-tooth differential between the 2 rings was the max for shifting
> smoothness on the front der. Before I go and try a 52/34 combo,
> opinions please?
I have a 110 mm crank with a 52-34 chainring. I have not poblems
shifting. I have to shift slowly no to drop the chain. But if I drop
the chain, I just shift in the opposite direction while pedaling until
the chain re-engages.
|
| |
Date: 04 Jun 2007 13:50:18
From: Chris M
Subject: Re: Compact Crank Ring Differential
|
On Jun 4, 8:38 am, VeloJon <jprest...@comcast.net > wrote:
> According to Cyclingnews, several Giro riders were running 52/34 chain
> rings for the big climbs. I thought the conventional wisdom was that
> a 16-tooth differential between the 2 rings was the max for shifting
> smoothness on the front der. Before I go and try a 52/34 combo,
> opinions please?
I saw that too, and I assume they solved it with a custom / pre-
production front derailleur or a front derailleur intended for triple
ring cranksets. The derailleurs are the most important components that
limit these setups. It is also possible that the limit of 16 teeth
difference is merely a best case max rather than a hard limit. IOW,
you may be able to use this setup with some loss of shifting
performance. Even in the worst case, keep in mind that with a
difference of more than 16 teeth (say, 18) you are not going to be
shifting back and forth as much anyway so I would say that the
performance gain you get from this "beyond standard" setup may still
be worth the gain you get from these gears even factoring in the
slower, noisier, oe whatever that you have to put up with. Given that
the 16 teeth 50/34 cranksets can be used with typical derailleurs not
specific to the compact cranks, maybe you will get roughly the same
performance from a 52/34 with a compact designed front derailleur as
those that run 50/34 with a standard derailleur designed for 130-135
double ring cranks.
I would for for it and if you have to buy another pair of rings, how
bad can that be? You may find that the 50 tooth ring has less
influence than you think. Looking at gear charts, you will only need
to spin 6% faster. A 50*12 is slightly closer to a 53*13 than a 53*12,
but it is still bigger than a 53*13 and you may even find the 50*12 a
better gear for you than you had guessed. I would absolutely recommend
trying the gears first before you change the cassette. My hope for the
compact cranks (when I finally get around to changing) is closer gear
ratios. I can run a 12/21 or 12/23 in place of a 12/25< and even put
my existing cassettes back on for really mountainous terrain and leave
the 18 at home. I am convinced that a 50*12 is enough for me since I
have already spent enough time with a 50/39 (on a 135 bcd) to know
this. I guess that is one more option, to buy a budget 50T chainring
for an existing crank to see how much you really want or need to
change. There are so many options, you only need to decide what to try
first, so think it through comparing options side by side. You may not
really need the 18 tooth difference, or that you can get along with a
52/35, and that (only 1 tooth over the implied max.) I am sure will
not cause any problems. Some times these min. and max. specifications
come from variables that do not apply to your intended setup. As I
said, given that the standard double front derailleurs really work ok
with the 16 tooth differential, I can't imagine that a dedicated
(compact) design won't be just fine with 17 if not 18 teeth
differential to deal with. And... don't forget to make sure your rear
derailleur is up to the task with your intended cassette(s). I believe
this is precisely why Campagnolo brought out the medium length rear
derailleurs, which needs to be able to handle the larger rear cogs and
the chain wrap differential.
Don't forget to post your findings so that others can be more
confident in their choices (please).
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Date: 04 Jun 2007 18:10:36
From: Doug Taylor
Subject: Re: Compact Crank Ring Differential
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On Mon, 04 Jun 2007 13:50:18 -0700, Chris M
<chrismcreynolds1963@gmail.com > wrote:
>On Jun 4, 8:38 am, VeloJon <jprest...@comcast.net> wrote:
>> According to Cyclingnews, several Giro riders were running 52/34 chain
>> rings for the big climbs. I thought the conventional wisdom was that
>> a 16-tooth differential between the 2 rings was the max for shifting
>> smoothness on the front der. Before I go and try a 52/34 combo,
>> opinions please?
>
>I saw that too, and I assume they solved it with a custom / pre-
>production front derailleur or a front derailleur intended for triple
>ring cranksets. The derailleurs are the most important components that
>limit these setups. It is also possible that the limit of 16 teeth
>difference is merely a best case max rather than a hard limit. IOW,
>you may be able to use this setup with some loss of shifting
>performance. Even in the worst case, keep in mind that with a
>difference of more than 16 teeth (say, 18) you are not going to be
>shifting back and forth as much anyway so I would say that the
>performance gain you get from this "beyond standard" setup may still
>be worth the gain you get from these gears even factoring in the
>slower, noisier, oe whatever that you have to put up with. Given that
>the 16 teeth 50/34 cranksets can be used with typical derailleurs not
>specific to the compact cranks, maybe you will get roughly the same
>performance from a 52/34 with a compact designed front derailleur as
>those that run 50/34 with a standard derailleur designed for 130-135
>double ring cranks.
>
>I would for for it and if you have to buy another pair of rings, how
>bad can that be? You may find that the 50 tooth ring has less
>influence than you think. Looking at gear charts, you will only need
>to spin 6% faster. A 50*12 is slightly closer to a 53*13 than a 53*12,
>but it is still bigger than a 53*13 and you may even find the 50*12 a
>better gear for you than you had guessed. I would absolutely recommend
>trying the gears first before you change the cassette. My hope for the
>compact cranks (when I finally get around to changing) is closer gear
>ratios. I can run a 12/21 or 12/23 in place of a 12/25< and even put
>my existing cassettes back on for really mountainous terrain and leave
>the 18 at home. I am convinced that a 50*12 is enough for me since I
>have already spent enough time with a 50/39 (on a 135 bcd) to know
>this. I guess that is one more option, to buy a budget 50T chainring
>for an existing crank to see how much you really want or need to
>change. There are so many options, you only need to decide what to try
>first, so think it through comparing options side by side. You may not
>really need the 18 tooth difference, or that you can get along with a
>52/35, and that (only 1 tooth over the implied max.) I am sure will
>not cause any problems. Some times these min. and max. specifications
>come from variables that do not apply to your intended setup. As I
>said, given that the standard double front derailleurs really work ok
>with the 16 tooth differential, I can't imagine that a dedicated
>(compact) design won't be just fine with 17 if not 18 teeth
>differential to deal with. And... don't forget to make sure your rear
>derailleur is up to the task with your intended cassette(s). I believe
>this is precisely why Campagnolo brought out the medium length rear
>derailleurs, which needs to be able to handle the larger rear cogs and
>the chain wrap differential.
I've posted more than a few times my personal experience with front
derailleur shifting efficiency with the 16 tooth gap in the "typical"
50-34 compact ring set up.
My experience is that a standard derailleur works, but that anything
less than top of the line standard components (I run Shimano, so Dura
Ace front der. and shifter) works slowly and sluggishly shifting up
from 34 to 50. Actually, the best combo I have found for crisp and
quick upshifts is Dura Ace Shifter and FSA C-16 compact specific front
der.
So it would be my guess that standard front ders. would have a tough
time shifting 17 or 18 teeth up with any precision. They are, after
all, designed for 14 teeth.
Cassettes are another animal. If you want the benefit of lower gears
without sacrificing your highest gear, you necessarily are going to
end up with a wide block with more than a few 2 and even 3 tooth
jumps, even if you run a 10 speed.
In order to keep your high gear close to what it was with the standard
53:12, you need to run a 50:11. In order to get the benefit of a
lower low that 39:25 or even 39:27, you need to run at least a 26 with
your compact.
SRAM sells a 10 speed cassette with these cogs:
11/12/13/14/15/17/19/21/23/26
Your second lowest gear @ 34:23 is slightly lower than your lowest @
39:25 (and only slightly higher than 39:27); and you have one mega low
gear. That's what compact is all about. But you have three 2 tooth
jumps and one 3 tooth in your block as a trade off.
IRD sells 10 speed cassettes with these cogs:
11/12/13/14/15/17/19/21/23/25
and
11/12/13/15/17/19/21/23/25/28
While the former is pretty close to the SRAM, the latter would be a
nightmare for a straight block purist. But it yields 2 lower gears
than 39:27, so is a compromise that fools such as I are willing to
accept in order to hang on to the back of the pack uphill as well as
down.
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Date: 04 Jun 2007 18:17:48
From: Sandy
Subject: Re: Compact Crank Ring Differential
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Dans le message de
news:1180971489.611858.308730@m36g2000hse.googlegroups.com,
VeloJon <jprestley@comcast.net > a réfléchi, et puis a déclaré :
> According to Cyclingnews, several Giro riders were running 52/34 chain
> rings for the big climbs. I thought the conventional wisdom was that
> a 16-tooth differential between the 2 rings was the max for shifting
> smoothness on the front der. Before I go and try a 52/34 combo,
> opinions please?
They weren't swapping back and forth. One change for up - one change for
down. They could run the K7's almost full range in either ring.
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Date: 04 Jun 2007 08:58:15
From: RS
Subject: Re: Compact Crank Ring Differential
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In article
<1180971489.611858.308730@m36g2000hse.googlegroups.com >,
jprestley@comcast.net says...
>
>
>According to Cyclingnews, several Giro riders were running 52/34
chain
>rings for the big climbs. I thought the conventional wisdom was that
>a 16-tooth differential between the 2 rings was the max for shifting
>smoothness on the front der. Before I go and try a 52/34 combo,
>opinions please?
>
My recolletion from cyclingnews was a 52x36 with a 29 in back,
specifically for Diluca.
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Date: 05 Jun 2007 09:26:19
From: Helmut Springer
Subject: Re: Compact Crank Ring Differential
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RS <r_schiller@comcast.net > wrote:
> My recolletion from cyclingnews was a 52x36 with a 29 in back,
That does work flawlessly here, with an old DuraAce front and bar
end shifters.
--
MfG/Best regards
helmut springer
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