Believe me, they do. I had a huge difference between left and right leg (always causing backpain during long rides) - after 3 months of powercranking, the strength difference and back pain were completely gone. I don't need a scientific study to back this claim - I am just happy everything is solved. If people think that is anecdotal and worthless, fair enough :-)
I personally know 1 person who very successfully used powercranks to recover from a severe hipfracture (resulting in a huge imbalance). He is a pure cyclist and got his strength back very quickly as soon as he started riding independent cranks.
There is much more examples but some people just don't want to be convinced about anything positive related to them.

Sam
samgyde.com

Just wondering why he's unconvinced and how he came to that conclusion.


Maybe it's just the ten dollar words used in a nickel conversation has me confused though.

Very true! I always recommend people to get powercranks instead of a powermeter if budget is an issue. Much more value for money! And since you can cut down you running time you save on shoes as well :-)
Sam
samgyde.com

I can confirm another N=1 sample (me) on Powercranks helping the rehab of a broken ankle (2009) and rehab after the entire chain in my left leg from my groin down to my ankle was badly damaged in an accident where I smashed into a house head and left knee first during a race in 2011. At first I did start too early and I feel the PC's were actually detrimental as everything was not even strong enough to actively use the lifting muscles. But later in my recovery they were perfect. Depending on the injury, you could be so weak/uncoordinated that initially even a few pedal strokes are almost impossible, (at that point, conventional cranks will be much better). You need a basic amount of functionality in each leg to even use powercranks, and once you get there, then powercranks are hugely useful to restore full function without having the good leg push along the bad leg that is only "on for the ride". The nice thing is that the Powercranks do this in a non weight bearing environment, which is like those anti gravity treadmills (like the one that Kobe Bryant recently used)

http://sports.yahoo.com/...means-235709183.html

Right now they are helping with progress from another round of injury (hamstring tear in a very stupid fall) that I babied my way through in Vegas and Kona (horrendous runs, but I was not planning to not do these races....any other races, and I'd have packed it in for the year).

Sam,

I understand that it's easy to know if your back felt better but how do you know the strength difference was completely gone? As far as I can see all that you really could know is that you're exerting enough positive torque to get the cranks around but beyond that I see no way to tell how much force you're actually exerting.

Also it's interesting that the PC's helped your back but in the case of Stefanie. she had to stop using them in August because they were causing her back so much pain.

Hugh

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Genetics load the gun, lifestyle pulls the trigger.

Wow - lots of opinion here no idea this was such a hot button.
I bought a pair and I have a huge issue with my run and muscle imbalance. Here's hoping they help me with it!

Sam - wish I had seen the coupon before. I am waiting on the converter for my BB30 to get them installed. Do you only use them on your road bike or your TT too?

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++++++++++++++++++++++++++++++++++++
Member of FishTwitch - Arriving to T1 alone and watching you go by on the run.
My Blog: http://poseidom.wordpress.com

I only have TT bikes :-)
Sam
samgyde.com

Hey Hugh,

If there is a strength difference you will notice immediately on powercranks since the weaker leg won't keep up and will feel way more sore after a ride. Riding with an imbalance on a fixed crank tends to reinforce the imbalance by the way (since the stronger leg will compensate for the weaker leg and get stronger while the weaker stays weak). Ask people who have used powercranks after an accident for revalidation and they will perfectly explain how powercranks help you overcome imbalances.
Another thing:for me, in the beginning there was quite a big power difference between left and right leg while pedaling single leg. That difference is completely gone now.

As for Stefanie: the nature of her backpain (and other pains) is completely different than mine. My back pain was completely imbalance induced and was gone when the balance was gone (that diagnose - imbalance causing backpain - was made before I started on powercranks). Stefanie has been struggling with bike position in general. This is solved and I can assure you that she does the big bulk of her training on powercranks again and that powercranks weren't the cause of here issues at all.

Sam
samgyde.com

This thread? This is why we can't have nice things.

True. As soon as you try to have something nice, people try to put Powercranks on it.

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Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com

...which makes it even nicer :-) (or more useful at least)
Sam
samgyde.com

What is nice is having 4:30 beside your name on the Kona results and not beside the run split column (19 more minutes and I slide into the category I'd rather not be in for a long time) ! Everything else is just equipment.

OK if we are talking about what the cranks look like even an anodized black would be nice. The gold is just a bit too much for me. OK, there is a foot of snow outside and I have not taken the storage wax off my XC skis yet, so I will hit the rollers with powercranks and then the treadmill now.

OK, I've been back on the powercranks for 3 weeks, mainly short 30 min roller rides at high RPM 5 times per week to help with some rehab. I feel a bit better coordination in my left leg while running. For the first time in 3 years I was able to wind up the treadmill to 10 mph for short bursts @2% grade and did not feel like my left leg would curl up into an uncontrollable cramp (keep in mind I had to re learn how to walk, then jog, then pedal after nerve damage post accident). I have been riding at mainly 90-100 RPM to focus on "foot speed" doing things like 10x30-60 second at high RPM trying to hit 50 revs or 100 revs depending on whether it is 30 or 60 seconds.

I got on the computrainer for the first time lately on standard cranks and my perceived exertion was the same for short 1 min intervals at 270-290W what it was previously at 250-270W. I think it could just be because my left leg is feeling more comfortable actively contributing to the pedaling motion whereas before the right leg was doing some work for it. I feel this is mainly neural activation and getting the bad leg more actively in the game again. I'll keep riding the rollers like this frequently and over the Xmas holidays, I'll get on the CT for a proper FTP test and do a 5K "race" TT to see if all this is truly helping. For now, this data is anecdotal in the sense that it is not truly quantified....just short burst of "speed" (for me) that feel much better than it has in 2.5 years and I'm 48 so it is harder to feel good at speed.

By the way, I know if Frank was on here, he'd tell me to stop worrying about riding at high RPM and when I ride my bike for TT purposes, I'll just let the RPM self select ad probably gravitate down to 80 RPM for IM and 85 RPM for half IM, but for now, this is more of a coordination restoration effort.

I personally find high RPM training on PC's to be very taxing (hard to maintain) even with relatively low power output. However on a fixed gear (track bike) high inertia setup I find it relatively easy to maintain RPM's above 110 for extended periods.

So my new training strategy is to do PC at low (40-60) and intermediate (70-90) RPM's and do my high RPM (100-120) on my fixed gear.

I apply the same approach. Actually, I don't see the point of high rpm riding with powercranks at all (or even without powercranks - I never do high rpm sets).
80rpm is the perfect cadence for me in general with PC and is also my average race cadence.

Sam
samgyde.com

Sam, as an FYI, I am doing high RPM powercrank riding to improve my coordination. After I had an accident a few years ago, I could not even ride at 40 RPM without my left leg doing weird things like automatically unclick from the pedals. For IM and half IM racing I am now at 80 RPM and 85 RPM respectively now. I'm not trying to pick an RPM for those events, I just look at it after the races and that is what I end up at. But for now, I am trying to improve coordination, doing it on the rollers (plus it is minus 22 C outside this morning, so no interest in taking a bike outdoors till March). It is a relatively low inertia set up, so it makes it tough. I am trying to ride these at higher than running cadence (closer to 100 RPM for the harder intervals, 90 RPM for the rest).

Hi Sam,

I am very much considering buying a set of PC's for my MTB to start training with them. Somehow, I'm eager to try out and convinced it will help me, much the same way as I was convinced of Rotor Q-rings when I started using them 8+ years ago and everyone was laughing with them. I've just recently switched over to O-Symmetric rings since my 3rd pair of Q-rings where finally worn enough to replacer them.

I guess winter-time would be the best time to start with PC's since it is all low-volume anyway and very little hard work. so it should not affect bike-training too much. My training focus now is on running and swimming anyway.

I am hoping that PC's will help to fix my imbalance between left/right leg. I had a severe hamstring injury (80% torn, scar-tissue still very much there and noticeable) which never got treated and healed properly. According to my Quarq Power-meter, I've got a left/right power-balance of 44-56%. This on both road and tri-bike and is the average of riding approx. 10.000km, so not a one-off ride estimate. I'm typically high-cadence rider due to my MTB background. The Q-rings help in this respect, my lowest race-av is 93 rpm in a 70.3; highest race-av is 102rpm in a 1/4. I am known to have peak-rpm's in race well into the 120's for a short surge in a climb or break away from a pack of drafters.

I'm just curious if riding the PC's with O-Symmetric rings will have a impact on it's effectiveness/training purpose or if it's best to keep them with round-rings to maximize the "pull" effect.

Steven
Bredene-Belgium

hi sam, your coupon code doesn't seem to work for my country, (when that failed i tried yours, then the good ol' us AND a, but still no joy...?

I can tell you that the PC use will help your hamstring tear rehab. The rest of your questions, I think it will be tough for you to intially ride at higher RPM, and I think you will gravitate towards lower RPMs for half and full IM duration. Above 90 for Olympic tris would probably be fine.

I'll pass your message and PM you as well! Code should work in the US.
Sam
samgyde.com

Hey Steven,

With powercranks the orientation of the rings will not be fixed so no point using the oval rings. Of course you could mount the oval rings and check if orientation - on thus ovality - has any influance at all :) (I believe it does and always ride QXL rings from Rotor on fixed cranks in races).
The powercranks will help your pull effect for sure and have a huge impact on hamstring/hipflexor strength.

PM me if you need more info.

Sam
samgyde.com

thanks Sam, 'preciate it.

while you are online, i remember reading about your experimentation with short cranks a few years ago.

above (in this thread) you mention 165 -175 being optimum for you now. that's still a 10mm spread though. i wondered why? are you still experimenting (fine tuning)?

I have been experimenting with lengths ranging from 130-180.
In short my findings - which are very personal:
- any length between 155-175 is fine for me (in terms of long term power output)
- shorter than 155 is a bit hard on steep hills (unless I adjust gearing which I didn't)
- 130-155 still is ok in terms of power output but it affected my flexibility (I should say inflexibility) and some tendons in the groin area from pulling to actively during races

Some sidenotes:
- I have very tall legs (95cm inseam), so for me, a 175 crank feels not too long
- shortening cranks means increasing saddle height which is already high in my 175 setting. This poses problems with TT frame geometries and seatposts that usualy can't accomodate this height
- my steep position with short cranks (130) made the transition from bike to run tough for me (my core muscles cramped up) in the races I used short cranks.
- there seems to be no aerodynamic benefit riding short cranks (we thought there was)

My preference:
- I think I would prefer 160 but only if a frame had a BB drop of 85mm instead of 70mm. Such frames don't exist.

Conclusion:
- It is interesting to experiment with different cranklengths
- Better a crank a bit too short than too long
- You can change cranklength, seat height, handlebar setup but unfortunately, the position of the bottom brancket is fixed and I would prefer that to be lower when riding shorter cranks.

As I said, these are my personal experiences and I am sure there are lots of people that don't agree or have experienced other setups that work better for them. You have to find a balance between position, aerodynamics and power output and the determination of your optimum cranklength is for sure an important factor.

Hope this helps :-)
Sam
samgyde.com