Is anyone using "powercranks" and can they give us their thoughts

peterwright

I certainly concur with what you have been feeling. I HAVE to ride lower cadence and bigger gears throughout my rides and as such feel that I am getting valuable strength work which is certainly benefitting me when I get back on my regular race bike.
I also feel a much more whole leg tiredness rather than my normal sore quads feeling. To me this seems beneficial.

n_kee

sorry for being confusing, ill be more careful with my word choice here.

stomping stroke = stroke one developes with normal cranks
powercranks stroke = stroke one developes with powercranks

what i was trying to say was that the study that found that elite riders stomp more than non elite riders can't show that a "stomping stroke" is in any way better or worse than a "powercranks stroke" with respect to any trait you want to measure (power, efficiency, anything) because there is no comparison with any powercranks group. The only thing the study shows is that when using a "stomping stroke", elite athletes have more stomp than non-elites athletes.

I understand that this study shows that "having a perfectly round stroke is not essential", but only if everyone is using regular cranks and a "stomping stroke".

What Frank Day suggests is that powercranks are so different from regular cranks, that "having a perfectly round stroke is not essential", is no longer the case. While in the past elite athletes were most successful using a "stomping stroke", now they may be more successful using a "powercranks stroke".

The original paper was asking the question "how is an elite athletes stroke different to a non-elites athletes stroke when they are all using a "stomping stroke"?" I am not saying that its results are wrong, only that the results have no relevance to the powercranks issue because the "powercranks stroke" was not a part of the study.

the question is whether, after training with powercranks, the resulting musculature (loss in strength of the quads combined with the increase in strenght of the other legs muscles. ideally the other legs muscles may increase instrength to even match the original strength of the quads) and the improved round stroke, will move the bike more than having the original stomping stroke (with most force applied by the quads in the downstroke). it could be that for things like timetrialing a "powercranks stroke" is better, while for sprinting a "stomping stroke" is better.

andrewbradley

I _feel_ i pedal like a powercranker and even take the concept one (big) step further with ankling (there is no machine to force you to ankle). I also _feel_ like I am applying force in the direction of the pedal (ie 90 degrees to the crank). i can't help myself doing all this now.

The main issue is whether using more muscle groups can produce aerobic power or fatigue reduction benefits.

The "smoothness, roundness, evenness, spin" thing could well be a red herring.

Even a "mash" is "smooth" in that the rise to peak torque is gradual. It is a pulse but it's not an impact or anything so we're not looking at energy wastage due to "unevenness"

I know there's a whole industry built around improving the mechanics of pedalling, but If you want to talk about "improvement" in pedal stroke in terms of mechanics then that implies you know how to define the optimal pedal stroke from a biomechanical point of view.

Do pedal forces tell us the story?

Obviously the crank torque has to be in the drive direction, but do we necessarily want the force applied to the pedals to be as "effective" as possible i.e. at 90 degrees to the crank? (As I said, this is what i _feel_ I am doing)

I speculate that most thinking cyclists believe the answer to be yes and consider any clash with experimental data as a paradox.

But I reckon that's the old trap of confusing force and power. I believe that the optimal pedal stroke is where the muscles are inputting their power to the system of levers in an optimal way. Who knows what that means in terms of pedal forces?

Smoothness, roundness people often talk about "dead spots". Rotor cranks seem to be gathering a following because of this. These mean you spend more time on the downstroke at all cadences.

You would have thought physiologists might give a clear cut answer as to whether an increased duty cycle could possibly be fuelled aerobically.

Any takers?

ric_stern/RST

There are some studies coming out now on Rotor Cranks, which do appear to alter the duty cycle. However, from memory, I'm pretty sure (but not positive) that the results are equivocal.

Ric

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paulbernstein

paulbernstein

I think you are expressing your ideas clearly...one point, however, for reply..you mention the powercrank musculature, which suggests in part less strength in the quads..if this were to occur, it would be of some concern come race day..with this in mind, I try to get one long ride in a week on my racing or equivalent bike, in part to make sure that I don't lose anything, ie quad strength, while I am trying to gain something, ie whole leg strength...I also do leg exercises in the qym once a week most of the year, and seek out hills when using powercranks, as that is most like weight lifting on the bike..later I will do more intervals for power building...I don't know if this will lead to optimal performance come race day, but that is my hypothesis in my experiment of one..time will tell....On another matter, has everyone seen UK pro John Ibbotson's web page?...he trained on powercranks for four weeks and kept a log..ibboworld.com.....another empirical experiment of one,

ric_stern/RST

Paul,

can you please put your response in the same part that the quoted text goes in rather than in a reply. if you're not sure how to do this please send me a private message

cheers
ric

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ric_stern/RST

Unless there's something 'wrong' with you, or you're exceptionally small, then no matter what cycling you do, you will not increase your strength through cycling. Even pedalling at very low cadences (e.g. 30 revs/min) the forces are still very small, and are nowhere near the magnitude needed to increase strength.

Ric

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paulbernstein

I'll give you the benefit of the doubt and assume that we are using terms such as strength differently. There is nothing "wrong" with me other than I have been seriously training in sports for more than 40 years, and I am not exceptionally small..that said, I don't think it is radical to believe that if you use your muscles they can get stronger, and if you don't they will be weaker. Also I am talking about endurance strength and endurance power, which seems relevant to a repetitive activity like road cycling. Furthermore, I find that after gross preseason conditioning, strenght work (which precedes power work) is best done on the bike..hence slow cadance climbing in bigger gears. Basic Friel ideas. Nothing controvertial here. Also, I would respond privately to better learn how to use this forum if I knew how to do that. Assume you are communicating with someone from a previous century..:-)

ric_stern/RST

Under the text you've written, there's several square brackets with abbreviations in. Click the one that reads [PM] on the message of the person you want to respond too, you can then send whoever a private message.

Ric

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peterwright

I disagree with regards the on bike work not being signifcant enough to increase strength. On bike , low cadence hill work has been shown to increase climbing speed - I think it is safe to assume that this is partly doen to gains in strength. Whether off bike strength work has any real merit is certainly up for debate...

ric_stern/RST

the definition of strength is: the maximum force or tension generated by a muscle (or muscle groups)



Not necessarily true. To get stronger you have to increase the muscle cross sectional area (i.e. hypertrophy of the muscle).

In endurance trained athletes, it's possible, and highly likely that strength *decreases* are you get aerobically fitter



Actually, it is (controversial). Strength training *cannot* be completed on a bike. Strength can only be trained at very low velocities, even for e.g. doing low cadence work uphill is too quick -- this is endurance training

lots of threads on this in the cycling training forum
Ric

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ric_stern/RST

I'm sure low cadence hill work increases climbing speed (so does changes in environmental conditions too). assuming that you mean increases in power, it most likely does, although there's no reason to believe that it would be any more of a change than riding at the same power at a higher cadence (this would probably be more beneficial).

Irrespective of this it's highly unlikely it'll increase your strength. assuming that you ride up a hill at 250 W at 50 revs/min on 170mm cranks, you need a force of ~280 N (~ 28 kg)...

Ric

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paulbernstein

As I said, it appears that we are using our terms differently. Developing the ability to pick something very heavy up one time is not all that relevant to endurance cycling..my use of strength, and I can choose to define it as I wish, as this is an exercise in communication, is endurance strength. Also, I don't disagree that as we become aerobically fitter we may lose strength, which is why over the cycle or cycles of a year, we build base, strength wise and aerobically, then refine, compete, rest lose balance, start all over again etc etc until we are in the ground. So, each year we try to do it a bit smarter. Can we get "stronger" so that later in the season we are at a higher overall level in our competition. Different questions are explored at different times of the year, eg, are there ways of maintaining our strength at a higher level for longer periods of the season as we ultimately pursue our competitive goals. Hence the interest in powercranks for this years go round. Time will tell. If there was only one way to the goal, that would be very boring. Now I really have to shut this beast down, my computer, and get on the bike..