Deore 9spd 11-32/34 cassette with tiagra short cage rear mech?

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Date: 10 May 2007 06:16:53
From: al77
Subject: Deore 9spd 11-32/34 cassette with tiagra short cage rear mech?

Hello, Will a Deore 9spd 11-32 or even 11-34 cassette work on my road
bike with a tiagra short cage rear mech & 52/42 double chainset? If
not will it work with a deore rear mech?

I usually have a 12-27 cassette, but want to have some of that extra
range for steep climbs without having to move to a triple chainset if
that is possible..

Thanks, Alan

Date: 12 May 2007 20:30:18
From: Anthony DeLorenzo
Subject: Re: Deore 9spd 11-32/34 cassette with tiagra short cage rear mech?

On May 10, 6:16 am, al77 <alkenyo...@hotmail.com > wrote:
> Hello, Will a Deore 9spd 11-32 or even 11-34 cassette work on my road
> bike with a tiagra short cage rear mech & 52/42 double chainset? If
> not will it work with a deore rear mech?
>
> I usually have a 12-27 cassette, but want to have some of that extra
> range for steep climbs without having to move to a triple chainset if
> that is possible..
>
> Thanks, Alan

I just managed this with on an older bike with Shimano 105 short cage,
42/52 and a 7-speed 13-23 that I replaced with an 11-34. I got
everything working fine but it took a lot of time and definitely some
luck as well.

In the end, I had to replace the b-screw with a slightly longer one
and move the rear wheel all the way back in the dropouts for the
derailleur to clear the big cog. Chain length is basically at the
maximums for too short in the big-big and too long in the short-short.
Probably not recommended, but this was an old bike that the rider
wanted lower gearing without going to a lot of expense (ie a triple or
a new rear derailleur.)

In the end, I had to convert it to a modern freehub. LBS let me
scavenge in the backyard for a 7-speed freehub, so new chain and
cassette came to $40 and brought her lowest gear from 48 to 32
inches.

I doubt this would be possible on every bike, and definitely not
optimal, but it is definitely possible and functional. It shifts fine
to all gears, but being a 7-speed probably helps a lot there.

Regards,
Anthony

Date: 11 May 2007 01:54:45
From: al77
Subject: Re: Deore 9spd 11-32/34 cassette with tiagra short cage rear mech?

On 11 May, 16:07, al77 <alkenyo...@hotmail.com > wrote:
> On 11 May, 14:49, "Mike Jacoubowsky" <mik...@ix.netcom.com> wrote:
>
>
>
>
>
> > > Hello, Will a Deore 9spd 11-32 or even 11-34 cassette work on my road
> > > bike with a tiagra short cage rear mech & 52/42 double chainset? If
> > > not will it work with a deore rear mech?
>
> > There are reasons why long-cage rear derailleurs exist, and trying to use a
> > cassette with a very large cog is one. You can fake it a bit by tightening
> > the "B" tension screw, which moves the derailleur away from the cogs, but
> > doing so adversely affects shifting in the smaller cogs, because it reduces
> > chain wrap. It can also make skipping more likely as well.
>
> > Whether even that might work depends upon the length of the derailleur
> > hanger. If you have one that's longer than most, it's more likely the
> > derailleur will clear the larger cogs when shifting up into them. Otherwise,
> > it might instead just push up against the next-larger cog, instead of moving
> > the chain further up.
>
> > And finally, without the ability to hold enough chain, you might have
> > problems getting the bike to shift into all possible gears without damaging
> > the derailleur and possibly the frame. Even though you might think you'll
> > never shift into the large/large combo, it happens anyway. And here's how-
> > you're heading up a hill, you're tired, it's hot, and you're not exactly at
> > your best. All you know is that you need a lower gear, so you reach for that
> > rear shift lever and click it one step lower and BLAMMO, you didn't realize
> > you were still in the large front chainring and you've now ripped your rear
> > derailleur out of the hanger, and possibly damaged the frame as well.
>
> > > I usually have a 12-27 cassette, but want to have some of that extra
> > > range for steep climbs without having to move to a triple chainset if
> > > that is possible..
>
> > Reasonable from a standpoint of saving the expense, but otherwise, modern
> > triples work extremely well, and allow for much smaller spacing between
> > gears. You're not as likely to wish you had something just a bit smaller or
> > larger.
>
> > > Thanks, Alan
>
> > --Mike-- Chain Reaction Bicycleswww.ChainReactionBicycles.com
>
> Maybe I could just change my smaller front chainring to something
> lower than 42T, 39T maybe? How can i work out which combination will
> give the easiest gear?
>
> i.e. 12-27 cass with 52/42 chainrings
> vs. 12-27 cass with 52/39 chainrings
> vs. 11-32 cass with 52/42 chainrings
> vs. 11-32 cass with 52/39 chainrings etc?
>
> & if i go for the 11-32 cass will the deore mech be more appropriate
> than a long cage tiagra mech? I don't want to risk the rear mech
> eating the frame as mentioned above. This setup will be for a soma
> smoothie frame where the mech hanger is part of the frame.
>
> Thanks for all the help, Alan- Hide quoted text -
>
> - Show quoted text -

I found Sheldons Gear Ration calculator so i'll work out the
differences with that. I have a triple on my tourer which has 12-27 &
53+42+32? Not sure on the smallest ring, i'll check that out & maybe
do some research in the hills with no panniers..

http://www.sheldonbrown.com/gears/

Date: 11 May 2007 01:07:48
From: al77
Subject: Re: Deore 9spd 11-32/34 cassette with tiagra short cage rear mech?

On 11 May, 14:49, "Mike Jacoubowsky" <mik...@ix.netcom.com > wrote:
> > Hello, Will a Deore 9spd 11-32 or even 11-34 cassette work on my road
> > bike with a tiagra short cage rear mech & 52/42 double chainset? If
> > not will it work with a deore rear mech?
>
> There are reasons why long-cage rear derailleurs exist, and trying to use a
> cassette with a very large cog is one. You can fake it a bit by tightening
> the "B" tension screw, which moves the derailleur away from the cogs, but
> doing so adversely affects shifting in the smaller cogs, because it reduces
> chain wrap. It can also make skipping more likely as well.
>
> Whether even that might work depends upon the length of the derailleur
> hanger. If you have one that's longer than most, it's more likely the
> derailleur will clear the larger cogs when shifting up into them. Otherwise,
> it might instead just push up against the next-larger cog, instead of moving
> the chain further up.
>
> And finally, without the ability to hold enough chain, you might have
> problems getting the bike to shift into all possible gears without damaging
> the derailleur and possibly the frame. Even though you might think you'll
> never shift into the large/large combo, it happens anyway. And here's how-
> you're heading up a hill, you're tired, it's hot, and you're not exactly at
> your best. All you know is that you need a lower gear, so you reach for that
> rear shift lever and click it one step lower and BLAMMO, you didn't realize
> you were still in the large front chainring and you've now ripped your rear
> derailleur out of the hanger, and possibly damaged the frame as well.
>
> > I usually have a 12-27 cassette, but want to have some of that extra
> > range for steep climbs without having to move to a triple chainset if
> > that is possible..
>
> Reasonable from a standpoint of saving the expense, but otherwise, modern
> triples work extremely well, and allow for much smaller spacing between
> gears. You're not as likely to wish you had something just a bit smaller or
> larger.
>
> > Thanks, Alan
>
> --Mike-- Chain Reaction Bicycleswww.ChainReactionBicycles.com

Maybe I could just change my smaller front chainring to something
lower than 42T, 39T maybe? How can i work out which combination will
give the easiest gear?

i.e. 12-27 cass with 52/42 chainrings
vs. 12-27 cass with 52/39 chainrings
vs. 11-32 cass with 52/42 chainrings
vs. 11-32 cass with 52/39 chainrings etc?

& if i go for the 11-32 cass will the deore mech be more appropriate
than a long cage tiagra mech? I don't want to risk the rear mech
eating the frame as mentioned above. This setup will be for a soma
smoothie frame where the mech hanger is part of the frame.

Thanks for all the help, Alan

Date: 11 May 2007 06:49:52
From: Mike Jacoubowsky
Subject: Re: Deore 9spd 11-32/34 cassette with tiagra short cage rear mech?

> Hello, Will a Deore 9spd 11-32 or even 11-34 cassette work on my road
> bike with a tiagra short cage rear mech & 52/42 double chainset? If
> not will it work with a deore rear mech?

There are reasons why long-cage rear derailleurs exist, and trying to use a
cassette with a very large cog is one. You can fake it a bit by tightening
the "B" tension screw, which moves the derailleur away from the cogs, but
doing so adversely affects shifting in the smaller cogs, because it reduces
chain wrap. It can also make skipping more likely as well.

Whether even that might work depends upon the length of the derailleur
hanger. If you have one that's longer than most, it's more likely the
derailleur will clear the larger cogs when shifting up into them. Otherwise,
it might instead just push up against the next-larger cog, instead of moving
the chain further up.

And finally, without the ability to hold enough chain, you might have
problems getting the bike to shift into all possible gears without damaging
the derailleur and possibly the frame. Even though you might think you'll
never shift into the large/large combo, it happens anyway. And here's how-
you're heading up a hill, you're tired, it's hot, and you're not exactly at
your best. All you know is that you need a lower gear, so you reach for that
rear shift lever and click it one step lower and BLAMMO, you didn't realize
you were still in the large front chainring and you've now ripped your rear
derailleur out of the hanger, and possibly damaged the frame as well.

> I usually have a 12-27 cassette, but want to have some of that extra
> range for steep climbs without having to move to a triple chainset if
> that is possible..

Reasonable from a standpoint of saving the expense, but otherwise, modern
triples work extremely well, and allow for much smaller spacing between
gears. You're not as likely to wish you had something just a bit smaller or
larger.

> Thanks, Alan

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

Date: 10 May 2007 20:55:17
From: JeffWills
Subject: Re: Deore 9spd 11-32/34 cassette with tiagra short cage rear mech?

On May 10, 5:16 am, al77 <alkenyo...@hotmail.com > wrote:
> Hello, Will a Deore 9spd 11-32 or even 11-34 cassette work on my road
> bike with a tiagra short cage rear mech & 52/42 double chainset? If
> not will it work with a deore rear mech?
>
> I usually have a 12-27 cassette, but want to have some of that extra
> range for steep climbs without having to move to a triple chainset if
> that is possible..
>
> Thanks, Alan

Given my druthers, I'd install the Deore rear derailleur and be done
with it. I've tried short-cage derailleurs with big cassettes and the
shifting is too compromised on the small cogs for my tastes.

Jeff

Date: 10 May 2007 10:47:00
From: Hank Wirtz
Subject: Re: Deore 9spd 11-32/34 cassette with tiagra short cage rear mech?