From: marcs@slc.com (Marc San Soucie)
Subject: Re: pedaling efficency
Organization: Servio Corp, Beaverton Oregon, US
Date: Tue, 14 Apr 1992 02:27:29 GMT

Jobst Brandt (hp1900_01@hplomg.hpl.hp.com) writes:

> Frank Williams writes:

> > ... I remain unconvinced.  My personal experience is that, regardless of
> > cadence, when I catch myself simply stomping down, I can always speed up
> > by pedaling "round".

> ... we are talking here of more then 90% of the work being
> done by the downstroke and whether including other muscles to augment this
> main muscle group improves energy conversion.  I believe it does not and
> I readily believe researchers who have not found any substantial work done
> by other muscles at peak output.

What other research has been done?


> ... The reasons for slower cadence when climbing
> were detailed at great length.  Because there is less kinetic energy and
> slower ground speed against a constant retarding force, the power stroke
> must be longer.  It gets longer by pushing over the top and all the way
> down to the bottom and even some backward pull.  Depending on the rider,
> this encompasses at least 180 degrees.  To recover from this long stroke,
> a longer rest period is needed and this can only be achieved by a slower
> cadence.

> Therefore, if one were to round pedal in the flats as riders must on
> steeper long grades, the cadence would drop to that used on such hills.
> In a TT, power is delivered at a fairly high cadence and it is limited
> to a main thrust between 1:30 and 4:00 o'clock.  The rest of the stroke
> is mostly follow through with relatively little power.  To experiment
> with the validity of the pulsed output let me suggest a method that
> makes this strikingly clear.  While cruising on the flats at 20+ mph,
> count mentally 1-2-3-1-2-3-1-2-3 pedaling only once every third pedal
> stroke so that you alternate between the legs.  I think you will notice
> that you can maintain practically the same speed with no additional
> effort with a strong pulse interspersed with a long recovery time.
> It is not smooth and it is not natural but it demonstrates recovery
> and an obviously short power pulse that is certainly less than 1/3 of
> the time.

Okay, now we're talking about some distinctions I can believe. I'll be
happier when I can read the research, but I'm willing to suspend my initial
disbelief about not pulling back during the higher cadences of
time-trialing, though I'm heartened to see mention of longer power strokes
during lower-cadence climbing. (I ought to add that for worse or for worse,
I tend to be a lower-cadence time-trialist as well).

You may already know that Eddie Borysewicz, in his 1984 book (in which he
makes no specific mention of any particular pedaling technique), recommends
a technique similar to that you've suggested for your experiment, as a
means of getting occasional rest for one or the other leg during time
trials. He recommends, if I recall correctly, a 3- or 4-to-1 stroke count -
three strokes on, one stroke off, alternating between legs. At least as of
1984 he was convinced that it offered equivalent or even increased speed
because of the rest cycles.

Nonetheless (and partly to get back to the original question), there is 
another experiment that would be interesting to run. Take a superior 
time-trialist and replace his or her pedals with quills and toestraps. 
Cover the quills with duct tape or some such, and remove the cleat from the 
shoe. This allows the rider to push down or pull up, but not to pull back 
on the pedals. Send the rider out for a good hard time-trial, and see what 
happens. Is the ride slower, or the same?

    Marc San Soucie
    Portland, Oregon
    marcs@slc.com