pedaling questions

Terrence Brannon said:

1 - from 0% (maximum dorsiflexion) to 100% (maximum plantarflexion),
what percent shoot the foot be at full extension when pedaling?

2 - from 0% (completely bent) to 100% (stiff and locked), how should
the leg be at full extension when pedaling

3 - do these answers vary between upright and recumbent bikes?

I suspect the answers vary from individual to individual on any cycle
and also with the exact setup of the cycle.

Aside from gross physiological differences between people, individuals
often have differences between feet and legs on left and right (for
example, my left ankle doesn't flex as much as the right due to
historical spraining injuries).

If you test setups empirically I think you're more likley to get a good
answer than following some Magic Formula worked out on someone else,
though that might give a good rule of thumb for a starting point.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

Terrence Brannon said:

1 - from 0% (maximum dorsiflexion) to 100% (maximum plantarflexion),
what percent shoot the foot be at full extension when pedaling?

2 - from 0% (completely bent) to 100% (stiff and locked), how should
the leg be at full extension when pedaling

3 - do these answers vary between upright and recumbent bikes?

I suspect the answers vary from individual to individual on any cycle
and also with the exact setup of the cycle.

Aside from gross physiological differences between people, individuals
often have differences between feet and legs on left and right (for
example, my left ankle doesn't flex as much as the right due to
historical spraining injuries).

I'll ditto Peter's remarks- but to answer your last question first,
I've set up recumbents with the same amount of extension on my leg as
my favorite upright, and found the extension to be too short. I guess
my feet point more in the recumbent position.

I also have trouble finding the perfect extension- but that' sbecause
my left leg is 1/2" longer than my right. When I'm tired, my right leg
has a smooth spin, but my left leg has a hitch in its stroke. People
who have watched my legs call it "hincky".

Start with enough extension to straighten your leg with your heel on
the pedal. That's a good starting point- but you'll need to fine-tune
from there.

Jeff

Very timely subject; I've been wondering the same thing.

With the heel/pedal straight-leg setup, I've been thinking of
increasing the leg extension. At rpm's above 70, it seems the legs are
pushing into me at the top of the stroke, making for a slight bouncing
effect.

Will probably try 1/2" or so.

On a DF, it was pretty easy to spot incorrect saddle height by
excessive hip movement up or down.

Dana

Additional extension did the trick with very little bouncing up to 90
rpm. There seems to be more power on the upstroke, too.

No new aches or pains the following day, either. Good news!

Dana