My thoughts on seat position, crank length, and cleat position

Jim Martin wrote:
wrote:
But what about duration of sustainable maximum power?

I'm not sure what you mean by this. something like time trial power? If
so, that gets to be a difficult thing to measure. So far we have stayed
away from performance trials.

I suppose that is what I mean, but in a much shorter time frame. What
do the curves look like for trying to generate maximum power with 100%
effort until exhaustion. How much power? How long? I don't know if this
would be interesting from a neuromuscular angle, but for cyclists it
would be very interesting.

In the submaximal article the weights of the 9 riders is mentioned, but
nothing about their heights. Is it possible that these findings do not
scale upward?

I suppose that's possible but I really doubt it. Also, for the max power
studies, I specifically recruited the tallest and shortest cyclists I
could find. The means may not be impressive but the range was pretty large.

What was the height range of subjects?

What do you think would happen were you to do these experiments with
more fine-grained crankarm lengths?

If there's no difference in an inch there will not likely be any
difference in 2.5mm

The incremental differences may be insignificant, but maybe between
175mm and 195mm there is room for a significant improvement and
degradation again. Particularly for semi-normal sized folks. Since 195
is regarded as huge, and 170 is normal, pehaps a more intermediate step
would be a worthwhile addition.


Any chance of you doing more research of this type any time soon?

Possibly. We have some indication that the ability to excite and relax
the muscle (pedaling rate) may be more subject to fatigue than muscle
force-velocity characteristits (pedal speed) and we'd like to take a
look at that. Keep in mind that my students and I do not study cycling.
We use cycing as a model to get at more basic questions of neuromuscular
function.

That sounds interesting. I am glad you and your students find cycling a
good vehicle for your studies, as your findings are very informative. I
know nothing of what sort of facilities you have, but here are some
nice adjustable cranks that may help with these type of experiments:
http://www.hscycle.com/Pages/adjustablecrankset.html

Thanks!

Joseph

wrote:
I suppose that is what I mean, but in a much shorter time frame. What
do the curves look like for trying to generate maximum power with 100%
effort until exhaustion. How much power? How long? I don't know if this
would be interesting from a neuromuscular angle, but for cyclists it
would be very interesting.

Okay I see what you mean. Yes, that is interesting to me and we may get
to that study sometime in the next year or two. It is what I tried to
describe earlier about fatigue mechanisms.

What was the height range of subjects?

5'4" to 6'6"

The incremental differences may be insignificant, but maybe between
175mm and 195mm there is room for a significant improvement and
degradation again. Particularly for semi-normal sized folks. Since 195
is regarded as huge, and 170 is normal, pehaps a more intermediate step
would be a worthwhile addition.

I don't think so. Your statement implies that the effect of crank
length, if there were one, would have local maxima/minima in between the
lengths we tested. I can't see that happening.

Cyclists really have trouble with our findings that crank length is not
important. I think one reason for that trouble is that cyclists can
detect differences of 2.5 mm and because they can detect such a small
difference they believe it must be important. Its not.

BTW, I am not just a science geek who ONLY uses cycling as a model. I
was a cat 1 track rider and cat 2 road rider, 3 time Texas State
champion and National masters champion on the track.

Cheers,

Jim

Jim Martin wrote:
I don't think so. Your statement implies that the effect of crank
length, if there were one, would have local maxima/minima in between the
lengths we tested. I can't see that happening.

But it is possible, and not _entirely_ unlikely.

Cyclists really have trouble with our findings that crank length is not
important. I think one reason for that trouble is that cyclists can
detect differences of 2.5 mm and because they can detect such a small
difference they believe it must be important. Its not.

So in your opinion, my improved performance after switching to 195 from
175 is due to placebo, and/or other factors such as my condition,
weather, etc. What was the range of possible positive effect from
different crank lengths? 2% improvement? 0.02%?


BTW, I am not just a science geek who ONLY uses cycling as a model. I
was a cat 1 track rider and cat 2 road rider, 3 time Texas State
champion and National masters champion on the track.

That's it! You're too strong! Frame-flex, heat disipation from
wheel-spin and other inefficiencies mask just how important crank
length is when you hit the track! ;-)

If any of your students want to ever do some sort of experiment, but
rounding up folks is a problem, they can feel free to contact me. I am
in a team of 30 riders who focus on long distance rides. Our main event
is a 540km race which we intend to do in 13:59 this year. The age range
is 18 to 59. We have acccess to VOmax, AT, and power, as well as the
other things measurable with a Polar at our local health club. Maybe
not ideal conditions with communications, etc, but maybe it would be
interesting for a student interested in a proof-of-concept type
experiment, and anything that has a side effect of helping individual
riders fine-tune their riding would help us reach our sub 14 hour goal.

Joseph