Rotor Cranks review ... hey, they really work!

Triathlon Forum
1

BTW, I got this off the cyclingnews.com web site - Gary

http://www.singletrackworld.com/i/rotor3_act.jpg

Rotor Cranks

I really enjoyed Ben Larsen’s review a few months back of the Rotor Cranks system. I’m passing comments on my own experience with Rotors thus far, and hope others will as well.

First, a few caveats.

  • It is winter here in the USA’s “mid-Atlantic” region (and what a winter it’s been!). I received and mounted my Rotor cranks on Dec 21st, and (due to the weather) all my experience thus far with them has been indoor training, with my TT-bike mounted on a Cateye CS-1000 trainer. But, as so few riders are yet using this system, I thought it might be worthwhile to provide feedback based on two months of indoor use.

  • My sole intended/desired application for the cranks – and thus, my entire calculus for their utility – is time trialing. In fact, its even narrower than that – it’s short (10k to 40k) TT’s on relatively flat, out-and-back courses. So if you primarily ride crits or climb mountains, even the little experience I have with them may not be relevant to your interests.

  • One final disclosure: on flat TT’s, I am a big gear “masher”, and I use long (180 mm) cranks. For those who are high rev spinners, the adjustment to the feel of the Rotors will no doubt take more getting used to than it did for someone with my approach.

On the other hand, I do have quite a few years’ worth of structured winter indoor training data against which to compare this winter’s experience with the Rotors. It’s therefore apples-to-apples (“ceterus paribus”) info. that I can impart here. I.E., same frame, trainer, rear wheel and tire – and because it’s indoor performance I’m assessing, weather, temperature and wind are definitely not factors in the mix.

Now the good news… For me, the Rotors have thus far yielded impressive benefits. If it ever stops snowing here, I hope to validate all this on the road relatively soon (my first season TT is April 5).

Objective data

The performance gains I’ve noticed for maximum efforts of 1km, 4km, and 40km, respectively, are on a par with those you recount in the “Testing” section of your own review.

Leave aside the fact that the CS-1000 trainer’s readouts are clearly quite a bit exaggerated (or else I’m an as-yet-undiscovered combination of Arnaud Tournant and Kent Bostick!), and use the following for comparative purposes only. All times “flying starts”: Best time 1995-2002 Best time winter 2002-2003 180mm DuraAce cranks 180mm Rotor cranks

1km 62.1 secs 58.0 secs 6.6%4km 4:34.3 4:21.2 4.8%40km 49:45 48:46 2.0%

Subjective data

The immediate effect I noticed – aside from getting more ‘result’ from a given amount of sustained effort – was that the location of post-maximal-effort soreness shifted, particularly in by upper and outer quadriceps.

It wasn’t more painful – just a slightly different locus. If you’ve ever done heavy squat work in the weight room, I would compare the sensation to that you might get from altering the position and width of your feet, or doing your squats with you heels on a slightly raised platform. A natural byproduct of stressing a different (and no doubt more powerful) muscle area, I would think.

Summary

Again, this feedback is necessarily preliminary – if it ever stops snowing here, I hope to validate all this on the road shortly (first season TT is April 5).

But I have done nearly 50 workouts using the Rotors, and frankly am very impressed with what I’ve experienced. I don’t think my overall fitness level at this point in the calendar is any different from what it’s been in past years – so if I’m getting more output “bang for the buck” from the Rotors indoors, that ought to lead to palpable gains on the road as well.

Thanks for your very helpful review. I’ll keep you posted.

best regards,

Richard Burkholder
Stockton NJ USA
(New Jersey state individual TT champion, masters age group: 1999, 2000, 2001, 2002)
Wednesday, February 26 2003

2

Gary,

You will be pleased to know that Ben just got a pair of PC’s to evaluate and compare to Rotor Cranks (and, yes, he did agree to use them exclusively).

We all await his review.

Frank

3

Our you gonna race on them?

On there website, order info is in spanish? Any english version? How much do they run?

4

I’d actually not be suprised if these provide benefit. I was looking into these the other day and the impression I got (which may certainly be wrong) is that these cranks are a mechanical approach/solution to address a biomechanical weakness. That is they are not designed to train the rider to ride better, rather they compensate for a weakness the rider has. The weakness being a power draining recovery. (The cranks speed up the recovery, basically the upstroke is shorter than the down stroke.) I would have guessed that these would not be UCI legal, but they are. If the benefit is substantial and immediate (no adaptation period), I wouldn’t be suprised to see these become a little more common.

As for how these compare to PCs, I think they’re two different beasts. One is a mechanical approach to go faster, the other is a mechanical approach to train the body to go faster. Unfortunately for PCs the effects of training the body are harder and take longer to prove. For triathletes, PCs have the reported advantage of benefitting the run.

5

I agree fully with Pooks assessment.

6

I’m sure that the RC’s provide little help for a triathletes run compared with PC’s.

RC’s dont care about the flexors, its all about applying pressure to the downstroke without the dead spot.

I dont use them but my shop owner has, although he didnt like the q factor and all the gearing inside the RC’s.

I’m going to watch the reviews, I am interested. It is a very good idea and would work well in my case for TT.

They would allow me to provide constant power to the downstroke and really push the gears without a dead spot delay.

In the last month I have actually regressed back to a 90 RPM rate for racing and my times are coming back down. The 80-85 RPM thing did not work as well for me.

7

If these do work, I imagine they’d be a godsend for a time trialer. It also looks to me like they could go through a few more design revs to reduce the q-factor. Although they are very substantial looking, I wonder if they are at all fragile mechanically.

8

a couple of things they would need to do:

  1. get a good US based distributor and warranty program in case the cranks fry

  2. reduce the internal gearing friction (I have read that there is some crunchiness in cold weather) to get it smooth, Rolhoff hubs have a lot of gearing and are smooth.

here are their tests, powercranks should have something like this on their web site:

http://rotorbike.ods.org/cgi-bin/Rotor/Rotor.dll/ENLACEACONTENIDO

10

Rotor cranks may indeed help shorten the duration of the non-power phase of the pedaling cycle. But to move down the road faster, you’d have to be putting more power into the drivetrain. That power would still have to come from the legs, and to get that extra power you’d have to train for it. I’d think that in order to see any benefits, you’d have to train to a) improve your power (which would benefit you on any cranks) and b) accustom yourself to the different rest interval.

11

You misrepresent what PC’s do. I think they optimize the fit between the machine and man instead of fitting the man to the machine. Both may be beneficial, only time will tell. I did mention to Ben Larsen that after he did his PC thing, and assuming that he got improvement, that he then see if Rotorcranks would cause further improvement. Are they additive? It would be interesting to see.

BTW Gary, I find it interesting that you are so quick to announce RC’s “work” on the basis of this one (or two) anecdotal report(s) while holding PC’s to task for not being proven despite many anecdotal reports of effectiveness.

Frank

13

Heh? Gary didn’t use that article to support his assertion. that is all.

This data (from the abstract) does support the hypothesis that lower cadences are more powerful though, especially when most or all of the power comes on the downstroke.

14

go to their web site Frank, there are several academic studies, notably by Dr Conconi who states a 16% power improvement, which is believable.

15

Gary,

I believe Dr. Conconi invented the things. So, his study is believeable and mine isn’t because his claim is less than mine?

Frank

16

My concern with “fitting the machine to the man” is that the machine is altered to do so. (obviously) Of course this is fine, but at what point has the machine become a different machine? The only reason I say this is that I would have thought that the conservative UCI would have considered rotor cranks to change the way a bike functions in such a fundamental way as to not be considered a UCI-legal bike. Obvioulsy they didn’t. In an extreme hypothetical, I wonder what would happen if these cranks turned out to be a true advantage that everyone moved toward them. I don’t think the UCI would be a fan of all riders riding on a superior (again, extreme hypothetical) though proprietary crank design.

In the sense that PC’s help the rider better ride what is the current standard crank design (I realize this is not yet “proven”), they may be taking the right approach. I don’t know. The designs are very different philosophically. One tries to improve the machine through changing it, and the other tries to help the rider get the most out of the existing standard. I’m certainly not making the stance that either approach is better than the other.

17

I have not read your study, where can I find it?

19

Where did I get my cadence idea from? Why don’t you read the study you cited and provided the abstract for. Power was highest at slowest downward pedal speed, not highest downward pedal speed. I won’t let you pick and choose studies to prove your point. So, there is a conter study to prove something else regarding cadence, then that study goes against the rotor cranks.

So, if it supports rotor cranks it supports slower cadences. If it doesn’t then it doesn’t. Which is it?

Frank

20

Gary writes: "I have not read your study, where can I find it? "

You can’t find it. I, at least, knew it would have little validity in “proving” anything so didn’t even try to publish it.

I did it so I would “know” what claims I could support. I must say I was surprised at the number. Nothing since has changed my mind. 40% power increase in the typical new user in 6-9 months, at least for reasonable distances. That is what my “study” showed. That is what the majority of new users report.

22

So why dont you put **“40% in 6 to 9 months” **on your web site instead of just “40% improvement”. And is the 40% still accurate if I use PowerCranks for say 50% of my riding and regular cranks for the other 50%? If not, how much would a pro racer that uses your cranks one day per week, or by 10% benefit?

Or is 40% based on riding the cranks all the time. Can you get specific with that 40% claim?

Very confusing.

The thing with Rotor Cranks is that you can use them and get instant results.

Why not publish your findings? Rotor Cranks has several studies on their web site.

Equip the Man, not Man the Equipment.

Empower the consumer.

23

I only had the abstract before but that data simply says there is an optimum leg extension rate for power generation. When downward stroke was slowed (LEP58) rotation increased to keep it somewhat optimal. When downward speed was increased (LEP42) cadence was decreased. too fast or too slow pedal speed and power falls off.

Look at what the foot is doing, not what the simple numbers are.

24

How does concept differ from that of biopace rings? The concept the same to me but a different approach to get there. If this is the case, won’t these likely cause the same knee issues which made biopace dissapear?

I am not saying that this is the case, just from what I can see this is how it appears. I have never seen rotor cranks in person and do not fully understand how they work.