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Main
Date: 10 Oct 2007 10:27:09
From: Hell and High Water
Subject: Gear times cadence = speed?
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If I'm on my trainer, and I know what gear I'm in, and what my cadence
is, how would I calculate what speed I would be travelling on the road?
TIA,
-Bob
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Date: 15 Oct 2007 12:24:40
From: Scott
Subject: Re: Gear times cadence = speed?
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On Oct 15, 11:40 am, Lou Holtman <lholremovet...@planet.nl > wrote:
> Hell and High Water wrote:
>
>
>
>
>
> > In article <470fdce...@news.nb.nu>, lholremovet...@planet.nl says...
> >> Hell and High Water wrote:
> >>> In article <470fc61...@news.nb.nu>, lholremovet...@planet.nl says...
> >>>> Hell and High Water wrote:
>
> >>>>> If I'm spinning at the same RPM, in the same gear, I'll be travelli=
ng at
> >>>>> the same speed.
>
> >>>>> Again, power has nothing to do with it. It's simple math.
>
> >>>>> -Bob
>
> >>>> The keyword here is '=EDf'.
> >>>> Yes the math is so simple, you asked us how ;-)
>
> >>> Hey, the math isn't simple, just the simple fact that gears times
> >>> cadence =3D speed.
>
> >>> -Bob
>
> >> Power =3D gear at a certain cadence =3D speed.
>
> > If I'm going up a hill while spinning at 100 rpm in my 52 (front) and 28
> > (rear) I'm going a certain MPH.
>
> > If I'm going down hill while spinning at 100 rpm in my 52 (front) and 28
> > (rear), I'm going at EXACTLY the SAME MPH.
>
> > Period. Math, with no input/need for a power level.
>
> Yes, the math is simple (and taken care of in the second post), yes
> power is not in that speed equation, but me and others are trying to
> explain something that is beyond that (meaningless) equation.
> Lou
> --
> Posted by news://news.nb.nu (http://www.nb.nu)- Hide quoted text -
>
> - Show quoted text -
Lou, at least you're admitting you're trying to answer a question the
OP didn't ask. And, FWIW, if the OP wants to know the speed his rear
wheel is travelling while on his trainer, then it's not meaningless.
It may be meaningless to you, but that in and of itself is
meaningless.
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Date: 15 Oct 2007 21:45:14
From: Lou Holtman
Subject: Re: Gear times cadence = speed?
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Scott wrote:
> On Oct 15, 11:40 am, Lou Holtman <lholremovet...@planet.nl> wrote:
>> Hell and High Water wrote:
>>
>>
>>
>>
>>
>>> In article <470fdce...@news.nb.nu>, lholremovet...@planet.nl says...
>>>> Hell and High Water wrote:
>>>>> In article <470fc61...@news.nb.nu>, lholremovet...@planet.nl says...
>>>>>> Hell and High Water wrote:
>>>>>>> If I'm spinning at the same RPM, in the same gear, I'll be travelling at
>>>>>>> the same speed.
>>>>>>> Again, power has nothing to do with it. It's simple math.
>>>>>>> -Bob
>>>>>> The keyword here is 'íf'.
>>>>>> Yes the math is so simple, you asked us how ;-)
>>>>> Hey, the math isn't simple, just the simple fact that gears times
>>>>> cadence = speed.
>>>>> -Bob
>>>> Power = gear at a certain cadence = speed.
>>> If I'm going up a hill while spinning at 100 rpm in my 52 (front) and 28
>>> (rear) I'm going a certain MPH.
>>> If I'm going down hill while spinning at 100 rpm in my 52 (front) and 28
>>> (rear), I'm going at EXACTLY the SAME MPH.
>>> Period. Math, with no input/need for a power level.
>> Yes, the math is simple (and taken care of in the second post), yes
>> power is not in that speed equation, but me and others are trying to
>> explain something that is beyond that (meaningless) equation.
>
>> Lou
>> --
>> Posted by news://news.nb.nu (http://www.nb.nu)- Hide quoted text -
>>
>> - Show quoted text -
>
> Lou, at least you're admitting you're trying to answer a question the
> OP didn't ask. And, FWIW, if the OP wants to know the speed his rear
> wheel is travelling while on his trainer, then it's not meaningless.
> It may be meaningless to you, but that in and of itself is
> meaningless.
>
I can agree with that ;-)
lou
--
Posted by news://news.nb.nu (http://www.nb.nu)
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Date: 14 Oct 2007 14:59:06
From: nmp
Subject: Re: Gear times cadence = speed?
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Tom Sherman wrote:
> nmp who? wrote:
>> Hell and High Water wrote:
>>
>>> In article <470fc610$1@news.nb.nu>, lholremovethis@planet.nl says...
>>>> Hell and High Water wrote:
>>>>
>>>>> If I'm spinning at the same RPM, in the same gear, I'll be
>>>>> travelling at the same speed.
>>>>>
>>>>> Again, power has nothing to do with it. It's simple math.
>>
>>>> The keyword here is 'Ãf'.
>>>> Yes the math is so simple, you asked us how ;-)
>>
>>> Hey, the math isn't simple, just the simple fact that gears times
>>> cadence = speed.
>>
>> It's only not simple for people who think it should be difficult.
>>
>> v = velocity in m/s
>> rpm = rotations per minute of the crank axle (cadence) teeth1 = no. of
>> teeth on front sprocket teeth2 = no. of teeth on rear sprocket c =
>> circumference of rear wheel in millimeters
>>
>> Thus:
>>
>> v = ( rpm / 60 ) * ( teeth1 / teeth2 ) * c
>>
>> Simple! ;)
>
> butbutbut, what if you have an internally geared hub [1] in the mix, or
> a mid-drive step-up gear [2]? ;)
>
> [1] Have one (1).
> [2] Have three (3).
You already know the answer, I presume.
Anyway, here is a nice calculator: <http://www.soulbikes.com/gears/ >
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Date: 12 Oct 2007 23:45:34
From: nmp
Subject: Re: Gear times cadence = speed?
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Scott wrote:
> Geezus H Krist, are you the most anal-retentive knucklehead ever?
Yes, that would be me :P
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Date: 12 Oct 2007 16:39:43
From: dustoyevsky@mac.com
Subject: Re: Gear times cadence = speed?
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On Oct 10, 10:11 pm, A Muzi <a...@yellowjersey.org > wrote:
> > carlfo...@comcast.net wrote:
> > (snip) you know,
> >> all the digital details that separate us from thebeaststhatperish.
> dustoyev...@mac.com wrote:
> > Are you saying you don't believe in Dog Heaven, Carl?
> > IMS, I think you saw a hopeful snake once.
> > Too bad we don't get the answers to these questions here first
> > (assuming, of course).
>
> Eventually we'll all know. Or not.
Or only continue getting the mushroom treatment.
Why should the sadistic aliens whose science project we are reveal the
true nature of our existence, unless to cause further anguish?
http://bible.cc/psalms/49-12.htm
Well, lots of translation variation. One might be correct. Or not.
<g >.
King James (this being the Wodehouse reference I guess):
"Nevertheless man being in honour abideth not: he is like the beasts
that perish."
"Life's a bitch*, then you die"? --D-y
*the "good" meaning of bitch, of course.
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Date: 12 Oct 2007 14:27:57
From: Scott
Subject: Re: Gear times cadence = speed?
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On Oct 11, 11:53 am, nmp <addr...@is.invalid > wrote:
> Hell and High Water wrote:
>
>
>
>
>
> > In article <470d4cff$0$240$e4fe5...@news.xs4all.nl>, addr...@is.invalid
> > says...
> >> Hell and High Water wrote:
>
> >> > In article <470d1b6e$0$240$e4fe5...@news.xs4all.nl>,
> >> > addr...@is.invalid says...
> >> >> Hell and High Water wrote:
>
> >> [..]
>
> >> >> > Power has nothing to do with that mathematical calculation.
>
> >> >> But what you propose is an incomplete mathemetical calculation.
>
> >> > Nope.
>
> >> > Check out:
>
> >> >http://www.sheldonbrown.com/gears/
>
> >> > It's as simple as wheelsize/chainring/cog/rpm
>
> >> > Power is not an element.
>
> >> But it is when you factor in real world variables like rolling
> >> resistance, aerodynamics, gravity (when going uphill), etc.
>
> > Nope.
>
> > If I'm spinning at a set RPM, the cogs/chain/wheels are spinning at a
> > set speed.
>
> > Period.
>
> This is true. I did not deny that.
>
> > If I'm spinning at that RPM *UP* a steep hill, or if I'm spinning at
> > that RPM *DOWN* a hill. Doesn't matter.
>
> > The math stays the same.
>
> But you seem to be thinking that you can turn the same amount of RPMs in
> any condition, regardless of the other variables that I've mentioned.
>
> Good luck with that.
>
> In more realistic terms: whatever you do on your stationary bike has
> little to do with what you would actually achieve on the road. You could
> perhaps be spinning very fast on your training bike, making lots of
> virtual miles (while always staying in the same place), and you'd be
> surprised how little miles that same amount of effort would get you in
> the real world. Or even vice versa, depending on the configuration of
> your training material.
>
> Riding on rollers DOES NOT EQUAL riding on road.
>
> If you are really fanatical & serious about performance, you would
> measure your performance on the stationary bike not in distance travelled
> (you are not travelling) but in power generated. This is what several
> people have already tried to explain to you.- Hide quoted text -
>
> - Show quoted text -
Geezus H Krist, are you the most anal-retentive knucklehead ever?
Read the initial post and understand what the OP was asking. Forget
about the fact that he mentioned both his trainer and the road in the
same sentence. ALL he wants to know is how to calculate wheel speed
if he knows gear ratio and cadence.
Yes, it IS a simple mathematical equation and the speed achieved in a
given gear ratio at a give cadence will not change whether indoors or
out. Yes, the power required to achieve that speed will vary, BUT
that's not what he asked.
If you weren't so busy looking to argue about something or to prove
how smart you are, you'd have seen it really is just that simple.
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Date: 15 Oct 2007 07:58:27
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
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In article <1192224477.225163.67810@v29g2000prd.googlegroups.com >,
hendricks_scott@hotmail.com says...
> Geezus H Krist, are you the most anal-retentive knucklehead ever?
> Read the initial post and understand what the OP was asking. Forget
> about the fact that he mentioned both his trainer and the road in the
> same sentence. ALL he wants to know is how to calculate wheel speed
> if he knows gear ratio and cadence.
>
> Yes, it IS a simple mathematical equation and the speed achieved in a
> given gear ratio at a give cadence will not change whether indoors or
> out. Yes, the power required to achieve that speed will vary, BUT
> that's not what he asked.
>
> If you weren't so busy looking to argue about something or to prove
> how smart you are, you'd have seen it really is just that simple.
Thanks Scott.
Seems like you and I are the only ones who understand what I was asking!
-Bob
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Date: 13 Oct 2007 20:03:45
From: Tom Sherman
Subject: Re: Gear times cadence = speed?
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Scott Hendricks wrote:
> On Oct 11, 11:53 am, nmp <addr...@is.invalid> wrote:
>> Hell and High Water wrote:
>>
>>
>>
>>
>>
>>> In article <470d4cff$0$240$e4fe5...@news.xs4all.nl>, addr...@is.invalid
>>> says...
>>>> Hell and High Water wrote:
>>>>> In article <470d1b6e$0$240$e4fe5...@news.xs4all.nl>,
>>>>> addr...@is.invalid says...
>>>>>> Hell and High Water wrote:
>>>> [..]
>>>>>>> Power has nothing to do with that mathematical calculation.
>>>>>> But what you propose is an incomplete mathemetical calculation.
>>>>> Nope.
>>>>> Check out:
>>>>> http://www.sheldonbrown.com/gears/
>>>>> It's as simple as wheelsize/chainring/cog/rpm
>>>>> Power is not an element.
>>>> But it is when you factor in real world variables like rolling
>>>> resistance, aerodynamics, gravity (when going uphill), etc.
>>> Nope.
>>> If I'm spinning at a set RPM, the cogs/chain/wheels are spinning at a
>>> set speed.
>>> Period.
>> This is true. I did not deny that.
>>
>>> If I'm spinning at that RPM *UP* a steep hill, or if I'm spinning at
>>> that RPM *DOWN* a hill. Doesn't matter.
>>> The math stays the same.
>> But you seem to be thinking that you can turn the same amount of RPMs in
>> any condition, regardless of the other variables that I've mentioned.
>>
>> Good luck with that.
>>
>> In more realistic terms: whatever you do on your stationary bike has
>> little to do with what you would actually achieve on the road. You could
>> perhaps be spinning very fast on your training bike, making lots of
>> virtual miles (while always staying in the same place), and you'd be
>> surprised how little miles that same amount of effort would get you in
>> the real world. Or even vice versa, depending on the configuration of
>> your training material.
>>
>> Riding on rollers DOES NOT EQUAL riding on road.
>>
>> If you are really fanatical & serious about performance, you would
>> measure your performance on the stationary bike not in distance travelled
>> (you are not travelling) but in power generated. This is what several
>> people have already tried to explain to you.- Hide quoted text -
>>
>> - Show quoted text -
>
> Geezus H Krist, are you the most anal-retentive knucklehead ever?
> Read the initial post and understand what the OP was asking. Forget
> about the fact that he mentioned both his trainer and the road in the
> same sentence. ALL he wants to know is how to calculate wheel speed
> if he knows gear ratio and cadence.
>
> Yes, it IS a simple mathematical equation and the speed achieved in a
> given gear ratio at a give cadence will not change whether indoors or
> out. Yes, the power required to achieve that speed will vary, BUT
> that's not what he asked.
>
> If you weren't so busy looking to argue about something or to prove
> how smart you are, you'd have seen it really is just that simple.
butbutbut, this is rec.bicycles.tech, where we like to have tetchy
discussions about such matters. :)
--
Tom Sherman - Holstein-Friesland Bovinia
Beer - It's not just for breakfast anymore!
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Date: 12 Oct 2007 21:15:12
From: nmp
Subject: Re: Gear times cadence = speed?
|
nmp wrote:
> v = velocity in m/s
> rpm = rotations per minute of the crank axle (cadence)
> teeth1 = no. of teeth on front sprocket
> teeth2 = no. of teeth on rear sprocket
> c = circumference of rear wheel in millimeters
Not millimeters but meters, of course...
> Thus:
>
> v = ( rpm / 60 ) * ( teeth1 / teeth2 ) * c
>
> Simple! ;)
>
> Use your own math to convert m/s to km/h or mph... Should be simple too.
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Date: 12 Oct 2007 21:09:13
From: nmp
Subject: Re: Gear times cadence = speed?
|
Hell and High Water wrote:
> In article <470fc610$1@news.nb.nu>, lholremovethis@planet.nl says...
>> Hell and High Water wrote:
>>
>> > If I'm spinning at the same RPM, in the same gear, I'll be travelling
>> > at the same speed.
>> >
>> > Again, power has nothing to do with it. It's simple math.
>> The keyword here is 'Ãf'.
>> Yes the math is so simple, you asked us how ;-)
> Hey, the math isn't simple, just the simple fact that gears times
> cadence = speed.
It's only not simple for people who think it should be difficult.
v = velocity in m/s
rpm = rotations per minute of the crank axle (cadence)
teeth1 = no. of teeth on front sprocket
teeth2 = no. of teeth on rear sprocket
c = circumference of rear wheel in millimeters
Thus:
v = ( rpm / 60 ) * ( teeth1 / teeth2 ) * c
Simple! ;)
Use your own math to convert m/s to km/h or mph... Should be simple too.
Just don't fool yourself into thinking that the amount of effort (power)
you put into "riding" any "distance" on your stationary training bike
will get you as far in the real world.
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Date: 13 Oct 2007 20:01:31
From: Tom Sherman
Subject: Re: Gear times cadence = speed?
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nmp who? wrote:
> Hell and High Water wrote:
>
>> In article <470fc610$1@news.nb.nu>, lholremovethis@planet.nl says...
>>> Hell and High Water wrote:
>>>
>>>> If I'm spinning at the same RPM, in the same gear, I'll be travelling
>>>> at the same speed.
>>>>
>>>> Again, power has nothing to do with it. It's simple math.
>
>>> The keyword here is 'Ãf'.
>>> Yes the math is so simple, you asked us how ;-)
>
>> Hey, the math isn't simple, just the simple fact that gears times
>> cadence = speed.
>
> It's only not simple for people who think it should be difficult.
>
> v = velocity in m/s
> rpm = rotations per minute of the crank axle (cadence)
> teeth1 = no. of teeth on front sprocket
> teeth2 = no. of teeth on rear sprocket
> c = circumference of rear wheel in millimeters
>
> Thus:
>
> v = ( rpm / 60 ) * ( teeth1 / teeth2 ) * c
>
> Simple! ;)
butbutbut, what if you have an internally geared hub [1] in the mix, or
a mid-drive step-up gear [2]? ;)
[1] Have one (1).
[2] Have three (3).
--
Tom Sherman - Holstein-Friesland Bovinia
Beer - It's not just for breakfast anymore!
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Date: 12 Oct 2007 17:40:40
From: nmp
Subject: Re: Gear times cadence = speed?
|
Hell and High Water wrote:
> In article <470f425f$0$240$e4fe514c@news.xs4all.nl>, address@is.invalid
> says...
>> Hell and High Water wrote:
>>
>> > In article <470e631c$0$226$e4fe514c@news.xs4all.nl>,
>> > address@is.invalid says...
>> >
>> >
>> >> If you are really fanatical & serious about performance, you would
>> >> measure your performance on the stationary bike not in distance
>> >> travelled (you are not travelling) but in power generated. This is
>> >> what several people have already tried to explain to you.
>> >
>> >
>> > LOL! I guess you missed my initial post.
>>
>> No. Your original post:
>>
>> "If I'm on my trainer, and I know what gear I'm in, and what my cadence
>> is, how would I calculate what speed I would be travelling on the
>> road?"
>>
>> Point is, if you were travelling on the road you probably would not be
>> in the same gear turning the same cadence. See?
>
>
> What, like it's physically impossible to be in the same gear at the same
> RPM if you're inside or outside?
>
>
> Seems like that's actually VERY possible.
What if you have a headwind? Sure, you could be cranking the same cadence
in the same gear. If you add POWER. But you did not believe that.
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Date: 12 Oct 2007 13:10:29
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
|
In article <470fb198$0$240$e4fe514c@news.xs4all.nl >, address@is.invalid
says...
> Hell and High Water wrote:
>
> > In article <470f425f$0$240$e4fe514c@news.xs4all.nl>, address@is.invalid
> > says...
> >> Hell and High Water wrote:
> >>
> >> > In article <470e631c$0$226$e4fe514c@news.xs4all.nl>,
> >> > address@is.invalid says...
> >> >
> >> >
> >> >> If you are really fanatical & serious about performance, you would
> >> >> measure your performance on the stationary bike not in distance
> >> >> travelled (you are not travelling) but in power generated. This is
> >> >> what several people have already tried to explain to you.
> >> >
> >> >
> >> > LOL! I guess you missed my initial post.
> >>
> >> No. Your original post:
> >>
> >> "If I'm on my trainer, and I know what gear I'm in, and what my cadence
> >> is, how would I calculate what speed I would be travelling on the
> >> road?"
> >>
> >> Point is, if you were travelling on the road you probably would not be
> >> in the same gear turning the same cadence. See?
> >
> >
> > What, like it's physically impossible to be in the same gear at the same
> > RPM if you're inside or outside?
> >
> >
> > Seems like that's actually VERY possible.
>
> What if you have a headwind? Sure, you could be cranking the same cadence
> in the same gear. If you add POWER. But you did not believe that.
If I'm spinning at the same RPM, in the same gear, I'll be travelling at
the same speed.
Again, power has nothing to do with it. It's simple math.
-Bob
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Date: 12 Oct 2007 21:07:57
From: Lou Holtman
Subject: Re: Gear times cadence = speed?
|
Hell and High Water wrote:
> If I'm spinning at the same RPM, in the same gear, I'll be travelling at
> the same speed.
>
> Again, power has nothing to do with it. It's simple math.
>
>
> -Bob
>
The keyword here is 'íf'.
Yes the math is so simple, you asked us how ;-)
Lou, sorry couldn't resist
--
Posted by news://news.nb.nu (http://www.nb.nu)
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| | | | |
Date: 12 Oct 2007 15:20:41
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
|
In article <470fc610$1@news.nb.nu >, lholremovethis@planet.nl says...
> Hell and High Water wrote:
>=20
> > If I'm spinning at the same RPM, in the same gear, I'll be travelling a=
t=20
> > the same speed.
> >=20
> > Again, power has nothing to do with it. It's simple math.
> >=20
> >=20
> > -Bob
> >=20
>=20
>=20
> The keyword here is '=EDf'.
> Yes the math is so simple, you asked us how ;-)
Hey, the math isn't simple, just the simple fact that gears times=20
cadence =3D speed.
-Bob
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Date: 12 Oct 2007 22:45:23
From: Lou Holtman
Subject: Re: Gear times cadence = speed?
|
Hell and High Water wrote:
> In article <470fc610$1@news.nb.nu>, lholremovethis@planet.nl says...
>> Hell and High Water wrote:
>>
>>> If I'm spinning at the same RPM, in the same gear, I'll be travelling at
>>> the same speed.
>>>
>>> Again, power has nothing to do with it. It's simple math.
>>>
>>>
>>> -Bob
>>>
>>
>> The keyword here is 'íf'.
>> Yes the math is so simple, you asked us how ;-)
>
>
>
> Hey, the math isn't simple, just the simple fact that gears times
> cadence = speed.
>
> -Bob
>
Power = gear at a certain cadence = speed.
Lou
--
Posted by news://news.nb.nu (http://www.nb.nu)
|
| | | | | | |
Date: 15 Oct 2007 07:57:27
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
|
In article <470fdce6$1@news.nb.nu >, lholremovethis@planet.nl says...
> Hell and High Water wrote:
> > In article <470fc610$1@news.nb.nu>, lholremovethis@planet.nl says...
> >> Hell and High Water wrote:
> >>
> >>> If I'm spinning at the same RPM, in the same gear, I'll be travelling=
at=20
> >>> the same speed.
> >>>
> >>> Again, power has nothing to do with it. It's simple math.
> >>>
> >>>
> >>> -Bob
> >>>
> >>
> >> The keyword here is '=EDf'.
> >> Yes the math is so simple, you asked us how ;-)
> >=20
> >=20
> >=20
> > Hey, the math isn't simple, just the simple fact that gears times=20
> > cadence =3D speed.
> >=20
> > -Bob
> >=20
>=20
>=20
> Power =3D gear at a certain cadence =3D speed.
If I'm going up a hill while spinning at 100 rpm in my 52 (front) and 28=20
(rear) I'm going a certain MPH.
If I'm going down hill while spinning at 100 rpm in my 52 (front) and 28=20
(rear), I'm going at EXACTLY the SAME MPH.
Period. Math, with no input/need for a power level.
-Bob
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| | | | | | | |
Date: 15 Oct 2007 19:40:40
From: Lou Holtman
Subject: Re: Gear times cadence = speed?
|
Hell and High Water wrote:
> In article <470fdce6$1@news.nb.nu>, lholremovethis@planet.nl says...
>> Hell and High Water wrote:
>>> In article <470fc610$1@news.nb.nu>, lholremovethis@planet.nl says...
>>>> Hell and High Water wrote:
>>>>
>>>>> If I'm spinning at the same RPM, in the same gear, I'll be travelling at
>>>>> the same speed.
>>>>>
>>>>> Again, power has nothing to do with it. It's simple math.
>>>>>
>>>>>
>>>>> -Bob
>>>>>
>>>> The keyword here is 'íf'.
>>>> Yes the math is so simple, you asked us how ;-)
>>>
>>>
>>> Hey, the math isn't simple, just the simple fact that gears times
>>> cadence = speed.
>>>
>>> -Bob
>>>
>>
>> Power = gear at a certain cadence = speed.
>
>
> If I'm going up a hill while spinning at 100 rpm in my 52 (front) and 28
> (rear) I'm going a certain MPH.
>
> If I'm going down hill while spinning at 100 rpm in my 52 (front) and 28
> (rear), I'm going at EXACTLY the SAME MPH.
>
> Period. Math, with no input/need for a power level.
Yes, the math is simple (and taken care of in the second post), yes
power is not in that speed equation, but me and others are trying to
explain something that is beyond that (meaningless) equation.
In the first place power determines in what gear you can spin 100 rpm in
real world conditions. So power is in the speed equation in real world
conditions.
People have a certain power level that they can sustain for a longer
period. You can train that on a trainer. People are happy with a certain
cadence. You can train that on a trainer (gear is irrelevant), but speed
calculated from a certain cadence and gear means nothing on a trainer
without knowing the power.
But if you are only interested in speed go ahead and use that equation
or buy a speedometer with a rear wheel sensor. They are cheap and you
don't have to count your RPM's as a bonus.
Lou
--
Posted by news://news.nb.nu (http://www.nb.nu)
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Date: 15 Oct 2007 15:10:50
From: Clive George
Subject: Re: Gear times cadence = speed?
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"Hell and High Water" <tifosoREM@OVEcomcast.net > wrote in message
news:MPG.217d1fb16fcc672b989b45@news.giganews.com...
>If I'm going up a hill while spinning at 100 rpm in my 52 (front) and 28
>(rear) I'm going a certain MPH.
Bet you can't do that up the alpe d'huez. Which is where the point about it
being a completely useless number comes from : you know the tyre speed on
the trainer, but given an actual real road, you won't be going at that speed
because you're not strong enough.
(and if you were strong enough, you're not trying hard enough on the
trainer. I suppose the trainer could have a realistic resistance, in which
case change the gradient of the road, and suddenly that trainer resistance
is wrong again).
clive
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Date: 12 Oct 2007 07:59:41
From: sergio
Subject: Re: Gear times cadence = speed?
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On Oct 12, 4:53 pm, Hell and High Water
> What, like it's physically impossible to be in the same gear at the same
> RPM if you're inside or outside?
> Seems like that's actually VERY possible.
Oh, yea!
Easier than excercising while in the water, to be sure.
Sergio
Pisa
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Date: 12 Oct 2007 09:46:07
From: nmp
Subject: Re: Gear times cadence = speed?
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Hell and High Water wrote:
> In article <470e631c$0$226$e4fe514c@news.xs4all.nl>, address@is.invalid
> says...
>
>
>> If you are really fanatical & serious about performance, you would
>> measure your performance on the stationary bike not in distance
>> travelled (you are not travelling) but in power generated. This is what
>> several people have already tried to explain to you.
>
>
> LOL! I guess you missed my initial post.
No. Your original post:
"If I'm on my trainer, and I know what gear I'm in, and what my cadence
is, how would I calculate what speed I would be travelling on the road?"
Point is, if you were travelling on the road you probably would not be in
the same gear turning the same cadence. See?
> I'm *NOT* fanatical nor am I *serious* about performance.
>
> I just want to figure out the friggin MATH. FOR THE HELL OF IT!!
If all you want to know is distance as a result of cadence and gear (and
wheel size), I think you already have the math. Right?
> I ride outside as much as I can, but if/when I'm stuck inside on the
> trainer, these things creep into my bored mind.
>
>
> '...hmmmm...if I was outside, doing this same rpm in this same
> gear....hmmmm...'
Yes, but you would be fooling yourself. The question is of no use beyond
entertaining your bored mind. You could as well be solving crossword
puzzles or something.
> or
>
> '....hmmmmm....if I can keep up a 120 cadence until the clock flips
> over, I'll reward myself with a mini-donut....mmmm....'
>
>
> WHATEVER! I'm certainly not going to spring $800 to measure my POWER.
OK, didn't say you had to :)
> I'm just trying to put some time in on the trainer until the friggin SUN
> comes up dude.
It does every day, or are you living in arctic territory?
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Date: 12 Oct 2007 09:53:20
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
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In article <470f425f$0$240$e4fe514c@news.xs4all.nl >, address@is.invalid
says...
> Hell and High Water wrote:
>
> > In article <470e631c$0$226$e4fe514c@news.xs4all.nl>, address@is.invalid
> > says...
> >
> >
> >> If you are really fanatical & serious about performance, you would
> >> measure your performance on the stationary bike not in distance
> >> travelled (you are not travelling) but in power generated. This is what
> >> several people have already tried to explain to you.
> >
> >
> > LOL! I guess you missed my initial post.
>
> No. Your original post:
>
> "If I'm on my trainer, and I know what gear I'm in, and what my cadence
> is, how would I calculate what speed I would be travelling on the road?"
>
> Point is, if you were travelling on the road you probably would not be in
> the same gear turning the same cadence. See?
What, like it's physically impossible to be in the same gear at the same
RPM if you're inside or outside?
Seems like that's actually VERY possible.
-Bob
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Date: 11 Oct 2007 17:53:32
From: nmp
Subject: Re: Gear times cadence = speed?
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Hell and High Water wrote:
> In article <470d4cff$0$240$e4fe514c@news.xs4all.nl>, address@is.invalid
> says...
>> Hell and High Water wrote:
>>
>> > In article <470d1b6e$0$240$e4fe514c@news.xs4all.nl>,
>> > address@is.invalid says...
>> >> Hell and High Water wrote:
>>
>> [..]
>>
>> >> > Power has nothing to do with that mathematical calculation.
>> >>
>> >> But what you propose is an incomplete mathemetical calculation.
>> >
>> > Nope.
>> >
>> > Check out:
>> >
>> > http://www.sheldonbrown.com/gears/
>> >
>> > It's as simple as wheelsize/chainring/cog/rpm
>> >
>> > Power is not an element.
>>
>> But it is when you factor in real world variables like rolling
>> resistance, aerodynamics, gravity (when going uphill), etc.
>
> Nope.
>
> If I'm spinning at a set RPM, the cogs/chain/wheels are spinning at a
> set speed.
>
> Period.
This is true. I did not deny that.
> If I'm spinning at that RPM *UP* a steep hill, or if I'm spinning at
> that RPM *DOWN* a hill. Doesn't matter.
>
> The math stays the same.
But you seem to be thinking that you can turn the same amount of RPMs in
any condition, regardless of the other variables that I've mentioned.
Good luck with that.
In more realistic terms: whatever you do on your stationary bike has
little to do with what you would actually achieve on the road. You could
perhaps be spinning very fast on your training bike, making lots of
virtual miles (while always staying in the same place), and you'd be
surprised how little miles that same amount of effort would get you in
the real world. Or even vice versa, depending on the configuration of
your training material.
Riding on rollers DOES NOT EQUAL riding on road.
If you are really fanatical & serious about performance, you would
measure your performance on the stationary bike not in distance travelled
(you are not travelling) but in power generated. This is what several
people have already tried to explain to you.
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Date: 11 Oct 2007 13:28:34
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
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In article <470e631c$0$226$e4fe514c@news.xs4all.nl >, address@is.invalid
says...
> If you are really fanatical & serious about performance, you would
> measure your performance on the stationary bike not in distance travelled
> (you are not travelling) but in power generated. This is what several
> people have already tried to explain to you.
LOL! I guess you missed my initial post.
I'm *NOT* fanatical nor am I *serious* about performance.
I just want to figure out the friggin MATH. FOR THE HELL OF IT!!
I ride outside as much as I can, but if/when I'm stuck inside on the
trainer, these things creep into my bored mind.
'...hmmmm...if I was outside, doing this same rpm in this same
gear....hmmmm...'
or
'....hmmmmm....if I can keep up a 120 cadence until the clock flips
over, I'll reward myself with a mini-donut....mmmm....'
WHATEVER! I'm certainly not going to spring $800 to measure my POWER.
I'm just trying to put some time in on the trainer until the friggin SUN
comes up dude.
-Bob
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Date: 11 Oct 2007 09:22:45
From: sergio
Subject: Re: Gear times cadence = speed?
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On Oct 11, 6:08 pm, A Muzi <a...@yellowjersey.org > wrote:
> > Wouldn't that be an improvement?
> As much improvement as perfume on a plastic girl doll.
Still, it would sell!
Sergio
Pisa
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Date: 11 Oct 2007 08:29:48
From: sergio
Subject: Re: Gear times cadence = speed?
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On Oct 10, 5:27 pm, Hell and High Water <tifoso...@OVEcomcast.net >
wrote:
> If I'm on my trainer, and I know what gear I'm in, and what my cadence
> is, how would I calculate what speed I would be travelling on the road?
I always feel sorry for people forced to excercise indoors.As
sympathetic as I am, let me fancy a way out of boredom for them
A computer assisted movie, showing a real cyclist, that would be run
at a speed matching your own.
Wouldn't that be an improvement?
Sergio
Pisa
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Date: 11 Oct 2007 11:08:27
From: A Muzi
Subject: Re: Gear times cadence = speed?
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> Hell and High Water <tifoso...@OVEcomcast.net> wrote:
>> If I'm on my trainer, and I know what gear I'm in, and what my cadence
>> is, how would I calculate what speed I would be travelling on the road?
sergio wrote:
> I always feel sorry for people forced to excercise indoors.As
> sympathetic as I am, let me fancy a way out of boredom for them
>
> A computer assisted movie, showing a real cyclist, that would be run
> at a speed matching your own.
> Wouldn't that be an improvement?
As much improvement as perfume on a plastic girl doll.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
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Date: 11 Oct 2007 07:26:56
From: Qui si parla Campagnolo-www.vecchios.com
Subject: Re: Gear times cadence = speed?
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On Oct 10, 9:27 am, Hell and High Water <tifoso...@OVEcomcast.net >
wrote:
> If I'm on my trainer, and I know what gear I'm in, and what my cadence
> is, how would I calculate what speed I would be travelling on the road?
>
> TIA,
>
> -Bob
get a rear wheel mount computer??
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Date: 10 Oct 2007 19:54:30
From:
Subject: Re: Gear times cadence = speed?
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On Oct 10, 4:54 pm, carlfo...@comcast.net wrote:
>
> Dear Bob,
>
> A roller spins the front tire at close enough to the same rate to the
> rear that it would work.
>
> But if you _really_ care about measuring your roller performance, you
> won't settle for anything less than the models shown here:
>
> http://www.bikecult.com/works/rollers.html
Regarding "Show-Offs, Skilled Stunts, and Striptease?" from that
page: http://www.bikecult.com/works/rollers/1948SchwLoretteBurke.jpg
Captain Dan Henry, whom I mentioned yesterday, used to put on a show
at League of American Wheelmen rallies, in which he'd ride the rollers
non-stop while gradually stripping down from a sweatsuit, through
several layers, to only a pair of Hawaiian swim trunks. When I saw
it, in the early 1980s, the finale was to hoist a banner held up by
two poles, one in each hand, as he rode the rollers no-hands.
As I said in a different thread, riding no-hands can be handly! (Of
course, Dan Henry did this on an upright bike, not on his recumbent.)
BTW, a further quirk (of which he had many): He never used toe clips
or other foot-to-pedal attachments. (Clipless were not yet in common
use.) He simply sawed a shallow groove in the leather soles of the
dress shoes he used for riding.
But with no toe clips, he couldn't crank with only one foot. So how
did he get his sweat pants off without falling off the rollers?
He spun the cranks up to about 200 rpm (that's by my watch), then as
the roller speed quickly coasted down, he'd work the pants partway
off. Repeating several times got his pants down below his knees, and
set him up for a final, furious speedup, which allowed him to slip one
leg out of the pants legs. He'd then repeat with the other.
A quirky but amazing thing to watch. Especially when done by a guy
who was (IIRC) about 70 years old.
Dan Henry was also the guy credited with inventing the idea of marking
century routes using arrows on the pavement.
- Frank Krygowski
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Date: 10 Oct 2007 19:28:32
From: Scott
Subject: Re: Gear times cadence = speed?
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On Oct 10, 12:35 pm, nmp <addr...@is.invalid > wrote:
> Hell and High Water wrote:
>
> > In article <470d0dc...@news.nb.nu>, lholremovet...@planet.nl says...
>
> >> Or forget about, it because the speed is 0 on a trainer and is in no
> >> way comparable with your speed outside on the road. People measuring
> >> speed and distance on a trainer don't get it IMO. Power and/or time
> >> that's what counts.
>
> > No, but if I'm inside, spinning at 100 RPM, I'd like to know what speed
> > I'd be going when I'm outside.
>
> If you were outside, would you be spinning at 100 RPM? And in the same
> gear? The circumstances would be so much different.
>
> > Power has nothing to do with that mathematical calculation.
>
> But what you propose is an incomplete mathemetical calculation.
gear inches x .2973 = mph @ 100 rpm (roughly)
I figured it out once when I wanted to be able to determine cadence
without a cadence-equipped cyclocomputer on my fixie. It's pretty
easy to remember the value for a given gear combo, then adjust for a
particular speed. For example, if I'm out tooling around in a 42x16
(or 70.8 GI) I know that at 21 mph I'm doing approx 100 rpm. Given
that, I know that 10 rpm = 2.1 mph. So, even in a fixie-induced haze
I can quickly tell that 18.9 mph = 90 rpm, 23.1 mph = 110 rpm, etc...
That way I don't need huge chart. I only need to know the mph @ 100
rpm speed for the given gear I'm using.
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Date: 11 Oct 2007 05:04:17
From: Michael Press
Subject: Re: Gear times cadence = speed?
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In article
<1192069712.654602.65420@y42g2000hsy.googlegroups.com >,
Scott <hendricks_scott@hotmail.com > wrote:
> On Oct 10, 12:35 pm, nmp <addr...@is.invalid> wrote:
> > Hell and High Water wrote:
> >
> > > In article <470d0dc...@news.nb.nu>, lholremovet...@planet.nl says...
> >
> > >> Or forget about, it because the speed is 0 on a trainer and is in no
> > >> way comparable with your speed outside on the road. People measuring
> > >> speed and distance on a trainer don't get it IMO. Power and/or time
> > >> that's what counts.
> >
> > > No, but if I'm inside, spinning at 100 RPM, I'd like to know what speed
> > > I'd be going when I'm outside.
> >
> > If you were outside, would you be spinning at 100 RPM? And in the same
> > gear? The circumstances would be so much different.
> >
> > > Power has nothing to do with that mathematical calculation.
> >
> > But what you propose is an incomplete mathemetical calculation.
>
> gear inches x .2973 = mph @ 100 rpm (roughly)
>
> I figured it out once when I wanted to be able to determine cadence
> without a cadence-equipped cyclocomputer on my fixie. It's pretty
> easy to remember the value for a given gear combo, then adjust for a
> particular speed. For example, if I'm out tooling around in a 42x16
> (or 70.8 GI) I know that at 21 mph I'm doing approx 100 rpm. Given
> that, I know that 10 rpm = 2.1 mph. So, even in a fixie-induced haze
> I can quickly tell that 18.9 mph = 90 rpm, 23.1 mph = 110 rpm, etc...
> That way I don't need huge chart. I only need to know the mph @ 100
> rpm speed for the given gear I'm using.
I tape that chart to the stem. For each gear
the speed in km / hour @ 90 cadence.
--
Michael Press
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Date: 10 Oct 2007 19:11:54
From: dustoyevsky@mac.com
Subject: Re: Gear times cadence = speed?
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On Oct 10, 3:03 pm, carlfo...@comcast.net wrote:
(snip) you know,
> all the digital details that separate us from the beasts that perish.
Are you saying you don't believe in Dog Heaven, Carl?
IMS, I think you saw a hopeful snake once.
Too bad we don't get the answers to these questions here first
(assuming, of course).
--D-y
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Date: 10 Oct 2007 22:11:32
From: A Muzi
Subject: Re: Gear times cadence = speed?
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> carlfo...@comcast.net wrote:
> (snip) you know,
>> all the digital details that separate us from the beasts that perish.
dustoyevsky@mac.com wrote:
> Are you saying you don't believe in Dog Heaven, Carl?
> IMS, I think you saw a hopeful snake once.
> Too bad we don't get the answers to these questions here first
> (assuming, of course).
Eventually we'll all know. Or not.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
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Date: 10 Oct 2007 20:27:01
From:
Subject: Re: Gear times cadence = speed?
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On Wed, 10 Oct 2007 19:11:54 -0700, "dustoyevsky@mac.com"
<dustoyevsky@mac.com > wrote:
>On Oct 10, 3:03 pm, carlfo...@comcast.net wrote:
>(snip) you know,
>> all the digital details that separate us from the beasts that perish.
>
>Are you saying you don't believe in Dog Heaven, Carl?
>
>IMS, I think you saw a hopeful snake once.
>
>Too bad we don't get the answers to these questions here first
>(assuming, of course).
>
>--D-y
Dear D,
Of course there's a Dog Heaven--it's for dogs, who will be allowed to
visit.
Cats are another matter. Let us simply say that they prefer a warmer
climate and leave it at that.
For those whose scriptural knowledge is deficient:
http://www.google.com/search?as_q=%22beasts+that+perish%22+wodehouse&hl=en&num=10&btnG=Google+Search&as_epq=&as_oq=&as_eq=&lr=&as_ft=i&as_filetype=&as_qdr=all&as_nlo=&as_nhi=&as_occt=any&as_dt=i&as_sitesearch=&as_rights=&safe=images
It appears in other books of the canon not yet available on the net.
Cheers,
Carl Fogel
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Date: 10 Oct 2007 22:06:55
From: nmp
Subject: Re: Gear times cadence = speed?
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Hell and High Water wrote:
> In article <470d1b6e$0$240$e4fe514c@news.xs4all.nl>, address@is.invalid
> says...
>> Hell and High Water wrote:
[..]
>> > Power has nothing to do with that mathematical calculation.
>>
>> But what you propose is an incomplete mathemetical calculation.
>
> Nope.
>
> Check out:
>
> http://www.sheldonbrown.com/gears/
>
> It's as simple as wheelsize/chainring/cog/rpm
>
> Power is not an element.
But it is when you factor in real world variables like rolling
resistance, aerodynamics, gravity (when going uphill), etc.
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Date: 11 Oct 2007 09:30:53
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
|
In article <470d4cff$0$240$e4fe514c@news.xs4all.nl >, address@is.invalid
says...
> Hell and High Water wrote:
>
> > In article <470d1b6e$0$240$e4fe514c@news.xs4all.nl>, address@is.invalid
> > says...
> >> Hell and High Water wrote:
>
> [..]
>
> >> > Power has nothing to do with that mathematical calculation.
> >>
> >> But what you propose is an incomplete mathemetical calculation.
> >
> > Nope.
> >
> > Check out:
> >
> > http://www.sheldonbrown.com/gears/
> >
> > It's as simple as wheelsize/chainring/cog/rpm
> >
> > Power is not an element.
>
> But it is when you factor in real world variables like rolling
> resistance, aerodynamics, gravity (when going uphill), etc.
Nope.
If I'm spinning at a set RPM, the cogs/chain/wheels are spinning at a
set speed.
Period.
If I'm spinning at that RPM *UP* a steep hill, or if I'm spinning at
that RPM *DOWN* a hill. Doesn't matter.
The math stays the same.
-Bob
>
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Date: 10 Oct 2007 20:53:24
From: Chalo
Subject: Re: Gear times cadence = speed?
|
Hell and High Water wrote:
>
> Lou Holtman says...
>
> > Or forget about, it because the speed is 0 on a trainer and is in no way
> > comparable with your speed outside on the road.
> > People measuring speed and distance on a trainer don't get it IMO. Power
> > and/or time that's what counts.
>
> No, but if I'm inside, spinning at 100 RPM, I'd like to know what speed
> I'd be going when I'm outside.
>
> Power has nothing to do with that mathematical calculation.
But power has everything to do with how fast you go on the road. If
you set up a roller and have tall enough gears on your bike, you can
get surface speeds on the rollers that are impossible when moving over
the ground. By decoupling the wheel's speed from ground speed and
airspeed, the wheel speed becomes irrelevant to how fast you'd
actually travel.
It's power to the wheel that decides your speed in the real world,
always. So use a power measuring device if you really have to know
that.
Chalo
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Date: 10 Oct 2007 14:03:13
From:
Subject: Re: Gear times cadence = speed?
|
On Wed, 10 Oct 2007 10:27:09 -0500, Hell and High Water
<tifosoREM@OVEcomcast.net > wrote:
>If I'm on my trainer, and I know what gear I'm in, and what my cadence
>is, how would I calculate what speed I would be travelling on the road?
>
>
>TIA,
>
>-Bob
Dear Bob,
You can set up a spreadsheet and plug in the data, using rpm, front to
rear gear ratio, and tire circumference, print a card for quick
reference, and tape it to your handlebar.
100 revs / minute
x
53 / 12 rear tire spins / revolution
x
2120 mm / tire-spin
----
936,333 mm / minute (speed!)
x
60 minutes / hour
x
1/1,609,344 miles / mm ( 1 / (25.4 x 12 x 5280)
----
34.9 miles / hour (useful speed!)
Or you can buy a $10 Schwinn cyclocomputer at WalMart, rig a set of
quick-release mounts for the rear tire and top tube, put the magnet on
the rear spoke, and obtain the real-time accuracy that's crucial to
really enjoying going nowhere.
The cyclocomputer would also let you know how far you'd spun the rear
tire, how long, the average speed, and the maximum speed--you know,
all the digital details that separate us from the beasts that perish.
Cheers,
Carl Fogel
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Date: 10 Oct 2007 15:12:30
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
|
In article <tqaqg3lamih4g6d5l6dlqkvqu2pi3lkuu0@4ax.com >,
carlfogel@comcast.net says...
> On Wed, 10 Oct 2007 10:27:09 -0500, Hell and High Water
> <tifosoREM@OVEcomcast.net> wrote:
>
> >If I'm on my trainer, and I know what gear I'm in, and what my cadence
> >is, how would I calculate what speed I would be travelling on the road?
> >
> >
> >TIA,
> >
> >-Bob
>
> Dear Bob,
>
> You can set up a spreadsheet and plug in the data, using rpm, front to
> rear gear ratio, and tire circumference, print a card for quick
> reference, and tape it to your handlebar.
>
> 100 revs / minute
> x
> 53 / 12 rear tire spins / revolution
> x
> 2120 mm / tire-spin
> ----
> 936,333 mm / minute (speed!)
> x
> 60 minutes / hour
> x
> 1/1,609,344 miles / mm ( 1 / (25.4 x 12 x 5280)
> ----
> 34.9 miles / hour (useful speed!)
>
> Or you can buy a $10 Schwinn cyclocomputer at WalMart, rig a set of
> quick-release mounts for the rear tire and top tube, put the magnet on
> the rear spoke, and obtain the real-time accuracy that's crucial to
> really enjoying going nowhere.
>
> The cyclocomputer would also let you know how far you'd spun the rear
> tire, how long, the average speed, and the maximum speed--you know,
> all the digital details that separate us from the beasts that perish.
>
> Cheers,
>
> Carl Fogel
Thanks so much Carl!
I'm also thinking about going to a roller. That would allow me to use
the cyclocomputer I've already GOT, right???
Any suggestions? (Other than to videotape it for YouTube!)
-Bob
>
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Date: 10 Oct 2007 14:54:25
From:
Subject: Re: Gear times cadence = speed?
|
On Wed, 10 Oct 2007 15:12:30 -0500, Hell and High Water
<tifosoREM@OVEcomcast.net > wrote:
>In article <tqaqg3lamih4g6d5l6dlqkvqu2pi3lkuu0@4ax.com>,
>carlfogel@comcast.net says...
>> On Wed, 10 Oct 2007 10:27:09 -0500, Hell and High Water
>> <tifosoREM@OVEcomcast.net> wrote:
>>
>> >If I'm on my trainer, and I know what gear I'm in, and what my cadence
>> >is, how would I calculate what speed I would be travelling on the road?
>> >
>> >
>> >TIA,
>> >
>> >-Bob
>>
>> Dear Bob,
>>
>> You can set up a spreadsheet and plug in the data, using rpm, front to
>> rear gear ratio, and tire circumference, print a card for quick
>> reference, and tape it to your handlebar.
>>
>> 100 revs / minute
>> x
>> 53 / 12 rear tire spins / revolution
>> x
>> 2120 mm / tire-spin
>> ----
>> 936,333 mm / minute (speed!)
>> x
>> 60 minutes / hour
>> x
>> 1/1,609,344 miles / mm ( 1 / (25.4 x 12 x 5280)
>> ----
>> 34.9 miles / hour (useful speed!)
>>
>> Or you can buy a $10 Schwinn cyclocomputer at WalMart, rig a set of
>> quick-release mounts for the rear tire and top tube, put the magnet on
>> the rear spoke, and obtain the real-time accuracy that's crucial to
>> really enjoying going nowhere.
>>
>> The cyclocomputer would also let you know how far you'd spun the rear
>> tire, how long, the average speed, and the maximum speed--you know,
>> all the digital details that separate us from the beasts that perish.
>>
>> Cheers,
>>
>> Carl Fogel
>
>Thanks so much Carl!
>
>I'm also thinking about going to a roller. That would allow me to use
>the cyclocomputer I've already GOT, right???
>
>
>Any suggestions? (Other than to videotape it for YouTube!)
>
>
>-Bob
Dear Bob,
A roller spins the front tire at close enough to the same rate to the
rear that it would work.
But if you _really_ care about measuring your roller performance, you
won't settle for anything less than the models shown here:
http://www.bikecult.com/works/rollers.html
Shipping charges for this model may be a tad high:
http://www.bikecult.com/works/rollers/1900rollers.jpg
Cheers,
Carl Fogel
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Date: 10 Oct 2007 23:04:57
From: Kinky Cowboy
Subject: Re: Gear times cadence = speed?
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On Wed, 10 Oct 2007 14:54:25 -0600, carlfogel@comcast.net wrote:
>On Wed, 10 Oct 2007 15:12:30 -0500, Hell and High Water
><tifosoREM@OVEcomcast.net> wrote:
>
>>
>>I'm also thinking about going to a roller. That would allow me to use
>>the cyclocomputer I've already GOT, right???
>>
>>
>>Any suggestions? (Other than to videotape it for YouTube!)
>>
>
>A roller spins the front tire at close enough to the same rate to the
>rear that it would work.
>
>But if you _really_ care about measuring your roller performance, you
>won't settle for anything less than the models shown here:
>
The only roller which makes a serious attempt to synthesise road
riding (i.e. using both inertial and fluid dynamic brakes, in
dynamometer terminology) is the TruTrainer
http://www.trutrainer.com/products_rollers.shtml
After you've lashed out the best part of $1000 on rollers, getting a
PowerTap or SRM to really tell you what you're doing won't seem so
expensive :-)
By the way, for quick and dirty calculations you can do in your head
remember that 100rpm on 100" gear is within 1% of 30mph
Kinky Cowboy*
*Batteries not included
May contain traces of nuts
Your milage may vary
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Date: 10 Oct 2007 18:35:26
From: nmp
Subject: Re: Gear times cadence = speed?
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Hell and High Water wrote:
> In article <470d0dcf$1@news.nb.nu>, lholremovethis@planet.nl says...
>
>> Or forget about, it because the speed is 0 on a trainer and is in no
>> way comparable with your speed outside on the road. People measuring
>> speed and distance on a trainer don't get it IMO. Power and/or time
>> that's what counts.
>
> No, but if I'm inside, spinning at 100 RPM, I'd like to know what speed
> I'd be going when I'm outside.
If you were outside, would you be spinning at 100 RPM? And in the same
gear? The circumstances would be so much different.
> Power has nothing to do with that mathematical calculation.
But what you propose is an incomplete mathemetical calculation.
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Date: 10 Oct 2007 14:14:15
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
|
In article <470d1b6e$0$240$e4fe514c@news.xs4all.nl >, address@is.invalid
says...
> Hell and High Water wrote:
>
> > In article <470d0dcf$1@news.nb.nu>, lholremovethis@planet.nl says...
> >
> >> Or forget about, it because the speed is 0 on a trainer and is in no
> >> way comparable with your speed outside on the road. People measuring
> >> speed and distance on a trainer don't get it IMO. Power and/or time
> >> that's what counts.
> >
> > No, but if I'm inside, spinning at 100 RPM, I'd like to know what speed
> > I'd be going when I'm outside.
>
> If you were outside, would you be spinning at 100 RPM?
Quite possibly. I'm trying to keep my cadence around 100 lately.
> And in the same
> gear?
I've only got seven. The odds are pretty good I'll hit a few of the
same ones, be it inside or outside...
> The circumstances would be so much different.
No kidding.
>
> > Power has nothing to do with that mathematical calculation.
>
> But what you propose is an incomplete mathemetical calculation.
Nope.
Check out:
http://www.sheldonbrown.com/gears/
It's as simple as wheelsize/chainring/cog/rpm
Power is not an element.
-Bob
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Date: 10 Oct 2007 10:42:34
From: Art Harris
Subject: Re: Gear times cadence = speed?
|
Hell and High Water wrote:
> If I'm on my trainer, and I know what gear I'm in, and what my cadence
> is, how would I calculate what speed I would be travelling on the road?
Try:
Speed (mph) = 0.0027 * Cadence * gear
But "riding" 20 mph on the trainer may be a lot easier (or harder)
than on the road.
Art Harris
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Date: 10 Oct 2007 09:26:36
From: russellseaton1@yahoo.com
Subject: Re: Gear times cadence = speed?
|
On Oct 10, 10:27 am, Hell and High Water <tifoso...@OVEcomcast.net >
wrote:
> If I'm on my trainer, and I know what gear I'm in, and what my cadence
> is, how would I calculate what speed I would be travelling on the road?
>
> TIA,
>
> -Bob
MPH = (Gear Inches * RPM) / 336.14 after dong the math.
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Date: 10 Oct 2007 09:09:09
From: Colin Campbell
Subject: Re: Gear times cadence = speed?
|
Hell and High Water wrote:
> If I'm on my trainer, and I know what gear I'm in, and what my cadence
> is, how would I calculate what speed I would be travelling on the road?
>
>
> TIA,
>
> -Bob
One way would be to check speed while you are riding on the road at a
certain gear and cadence. For example, I have been forcing myself to
ride in smaller gears for the past ten days, and I know that if I'm in
my 53 x 19, going 28 kph, I'm pedaling just over 80 rpm. At 31 kph, I'm
right around 90 rpm. I admit I haven't tried really hard to get totally
accurate numbers.
So, on the trainer, you could take the cadence and gear combo, and
"solve" for speed, based on what you learned on the road.
You could also work it out with pencil and paper.
Get your wheel diameter (you usually set your bike computer to the
diameter in millimeters, something on the order of 2093 if you ride on
23 mm tires - check it for accuracy!),
get your gear ratio (39 x 19 is 2.05 revs of the wheel for every rev of
the pedals),
multiply these two numbers to get the distance traveled in one pedal
revolution at that gear ratio (2093 mm x 2.05 = 4290.65 mm),
multiply that by your rpm (4290.65 x 80 = 343252 mm / minute),
multiply that by 60 minutes (20595120 mm), and
divide by 1,000,000 to convert to kilometers / hour (20.6 kph, or about
13 mph).
You can make a spreadsheet that covers the ratios for all of your gear
combinations and several cadence values, and paste it on the wall next
to your trainer.
Or, you could move to California, where you don't need no stinkin' trainer!
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Date: 10 Oct 2007 19:37:15
From: Lou Holtman
Subject: Re: Gear times cadence = speed?
|
Colin Campbell wrote:
> Hell and High Water wrote:
>> If I'm on my trainer, and I know what gear I'm in, and what my cadence
>> is, how would I calculate what speed I would be travelling on the road?
>>
>>
>> TIA,
>>
>> -Bob
>
> One way would be to check speed while you are riding on the road at a
> certain gear and cadence. For example, I have been forcing myself to
> ride in smaller gears for the past ten days, and I know that if I'm in
> my 53 x 19, going 28 kph, I'm pedaling just over 80 rpm. At 31 kph, I'm
> right around 90 rpm. I admit I haven't tried really hard to get totally
> accurate numbers.
>
> So, on the trainer, you could take the cadence and gear combo, and
> "solve" for speed, based on what you learned on the road.
>
> You could also work it out with pencil and paper.
> Get your wheel diameter (you usually set your bike computer to the
> diameter in millimeters, something on the order of 2093 if you ride on
> 23 mm tires - check it for accuracy!),
>
> get your gear ratio (39 x 19 is 2.05 revs of the wheel for every rev of
> the pedals),
>
> multiply these two numbers to get the distance traveled in one pedal
> revolution at that gear ratio (2093 mm x 2.05 = 4290.65 mm),
>
> multiply that by your rpm (4290.65 x 80 = 343252 mm / minute),
>
> multiply that by 60 minutes (20595120 mm), and
>
> divide by 1,000,000 to convert to kilometers / hour (20.6 kph, or about
> 13 mph).
>
> You can make a spreadsheet that covers the ratios for all of your gear
> combinations and several cadence values, and paste it on the wall next
> to your trainer.
>
> Or, you could move to California, where you don't need no stinkin' trainer!
Or forget about, it because the speed is 0 on a trainer and is in no way
comparable with your speed outside on the road.
People measuring speed and distance on a trainer don't get it IMO. Power
and/or time that's what counts.
Lou
--
Posted by news://news.nb.nu (http://www.nb.nu)
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Date: 10 Oct 2007 13:15:00
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
|
In article <470d0dcf$1@news.nb.nu >, lholremovethis@planet.nl says...
> Or forget about, it because the speed is 0 on a trainer and is in no way
> comparable with your speed outside on the road.
> People measuring speed and distance on a trainer don't get it IMO. Power
> and/or time that's what counts.
No, but if I'm inside, spinning at 100 RPM, I'd like to know what speed
I'd be going when I'm outside.
Power has nothing to do with that mathematical calculation.
-Bob
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Date: 10 Oct 2007 20:34:32
From: Lou Holtman
Subject: Re: Gear times cadence = speed?
|
Hell and High Water wrote:
> In article <470d0dcf$1@news.nb.nu>, lholremovethis@planet.nl says...
>
>> Or forget about, it because the speed is 0 on a trainer and is in no way
>> comparable with your speed outside on the road.
>> People measuring speed and distance on a trainer don't get it IMO. Power
>> and/or time that's what counts.
>
> No, but if I'm inside, spinning at 100 RPM, I'd like to know what speed
> I'd be going when I'm outside.
>
May I asked why?
> Power has nothing to do with that mathematical calculation.
True and it is not that difficult.
Lou
--
Posted by news://news.nb.nu (http://www.nb.nu)
|
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Date: 10 Oct 2007 14:11:35
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
|
In article <470d1b3b$1@news.nb.nu >, lholremovethis@planet.nl says...
> Hell and High Water wrote:
> > In article <470d0dcf$1@news.nb.nu>, lholremovethis@planet.nl says...
> >
> >> Or forget about, it because the speed is 0 on a trainer and is in no way
> >> comparable with your speed outside on the road.
> >> People measuring speed and distance on a trainer don't get it IMO. Power
> >> and/or time that's what counts.
> >
> > No, but if I'm inside, spinning at 100 RPM, I'd like to know what speed
> > I'd be going when I'm outside.
> >
>
> May I asked why?
I'm messing around with cadence lately, trying to keep my cadence around
100.
So as I change gears while spinning, it's interesting to me to think
about riding out on the road, and the corresponding speed I would be
travelling...
That's not hurting anyone, is it?
;-)
-Bob
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Date: 10 Oct 2007 11:19:41
From: Hell and High Water
Subject: Re: Gear times cadence = speed?
|
In article <470cf919$0$20558$4c368faf@roadrunner.com >,
cmcampb@adelphia.net says...
> Hell and High Water wrote:
> > If I'm on my trainer, and I know what gear I'm in, and what my cadence
> > is, how would I calculate what speed I would be travelling on the road?
> >
> >
> > TIA,
> >
> > -Bob
>
> One way would be to check speed while you are riding on the road at a
> certain gear and cadence. For example, I have been forcing myself to
> ride in smaller gears for the past ten days, and I know that if I'm in
> my 53 x 19, going 28 kph, I'm pedaling just over 80 rpm. At 31 kph, I'm
> right around 90 rpm. I admit I haven't tried really hard to get totally
> accurate numbers.
>
> So, on the trainer, you could take the cadence and gear combo, and
> "solve" for speed, based on what you learned on the road.
>
> You could also work it out with pencil and paper.
> Get your wheel diameter (you usually set your bike computer to the
> diameter in millimeters, something on the order of 2093 if you ride on
> 23 mm tires - check it for accuracy!),
>
> get your gear ratio (39 x 19 is 2.05 revs of the wheel for every rev of
> the pedals),
>
> multiply these two numbers to get the distance traveled in one pedal
> revolution at that gear ratio (2093 mm x 2.05 = 4290.65 mm),
>
> multiply that by your rpm (4290.65 x 80 = 343252 mm / minute),
>
> multiply that by 60 minutes (20595120 mm), and
>
> divide by 1,000,000 to convert to kilometers / hour (20.6 kph, or about
> 13 mph).
>
> You can make a spreadsheet that covers the ratios for all of your gear
> combinations and several cadence values, and paste it on the wall next
> to your trainer.
>
> Or, you could move to California, where you don't need no stinkin' trainer!
OUTSTANDING!!!
La Jolla? or Orinda?
Thanks so much!
-Bob
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