In article <
[email protected]>,
"Jay Beattie" <
[email protected]> wrote:
> "Sheldon Brown" <
[email protected]> wrote in message
>
news:[email protected]...
> > A shy person askked:
> >
> > > What is the significance to my training/general riding of pedaling two different bikes one
> > > with 175 and the other with
> > > 172.5 length crank arms?
> >
> > Precious little. The bike with longer cranks will provide a 1.4% lower gain ratio in a given
> > sprocket combination, so for the same gear it would climb a wee bit better, but not top out as
> > fast. Since you presumably have the option of changing gears, this difference, small as it is,
> > becomes utterly insignificant in practice.
>
> > The longer cranks will require you to bend your knee a bit farther for each stroke, possibly
> > leading to knee problems that a shorter crank might not cause, but, again, this difference is so
> > small it really doesn't matter.
>
> I know we always trade the same links (with the same equivocal studies) when this issue comes up,
> but is there really no good science on crank length? It would seem to me that the range-of-motion
> problem you raise would at least get some attention if it really does have the potential for
> causing injury. -- Jay Beattie.
IIRC the length cranks need to be before causing such an acute bend as to risk knee problems (in an
otherwise healthy knee) is really big. Where did I read that... maybe in the Hinault book? The size
mentioned- wherever I read it- was like 210 mm; and I would imagine that this would be proportional
to the leg length. With my 91 cm inseam, I should be able to ride 180s with no problem. I have a set
in the basement that I need to mount on a bike and see how they are.