Rotor any good?

[Bo Gevers]

Hi Guys,
I was thinking to maybe go to the Rotor crank for next season, I currently run a Shimano Ultegra 9 speed because my other 3 FSA Superlights broke this season!! I'm really tired of it!! Now because I play icehockey in the winter and I can't train as much as my concurrents I want to make my trainings as efficient as possible, I already bought a Powertap SL and now I was aking myself or the ROTOR crank is worth the extra weight (I don't really mind the weight when I have more efficient trainings) and if it is really an advantage? Can you guys help me out?
Thanks,

[Griswald4x4]

I wouldnt spend the money on the Crank just yet, Id buy the Rotor rings, and see if the concept works well for you. You can put them on any crank if you get the right BCD.

One of the guys in my shop tried it and it worked pretty well for him, the rings would give you a good idea if the whole crank is good for you.

[twistyaction usa]

I think the Rotor crank yields a more efficient output as you use it because it eliminates the dead spot mechanically, regardless of pedaling style. To actually eliminate (or at least reduce) the dead spot in your pedal stroke the Powercrankwould be a better training tool.

To simplify: The Rotor crank or Q-rings increase the amount of power that come out of your crankset into the chain. The Powercranks train you to put more power into your crankset.

I guess the ultimate would be to train on Powercranks and race on Rotors.

[John979]

I think the Rotor crank yields a more efficient output as you use it because it eliminates the dead spot mechanically, regardless of pedaling style. To actually eliminate (or at least reduce) the dead spot in your pedal stroke the Powercrankwould be a better training tool.

To simplify: The Rotor crank or Q-rings increase the amount of power that come out of your crankset into the chain. The Powercranks train you to put more power into your crankset.

I guess the ultimate would be to train on Powercranks and race on Rotors.

The "dead spot" concept and its relative "pedaling in circles" has no scientific foundation. In fact, Dr. Coyle in a peer-review study found quite the opposite, much to his surprise.

[Skillgannon]

Rotor cranks will not make you faster over the long term. Simple as that. Rotor cranks are designed for short term increases in efficiency due to the supposedly more efficient pedalling style involved (due to the rotating offset of the cranks) and possibly also fo rpeople with knee probelsm, as they may decrease the stress on the knee. But if you want to maximise your training through winter, Rotor cranks are not the way to go. You will go faster for a time, and will appear to put out more power on the Powertap, (after anatomical adaptation occurs, which would make you seem like youve made a performacnce leap) but they wont help you train. In fact, they may decrease your performance if you switch back to normal cranks because you wont have been using auxillary muscle groups as much with the rotors (eg. the much touted [by Powercranks] hip flexors) as you would with normal cranks.

You could try powercranks (as previously mentioned) as they isolate the pedalling so you have to pull up without the help of the other crank pulling down, which wil supposedly help your training. I'm not convinced about them, due to the losses in training time which will occur while you get used to them (they're supposedly a bitch to get used to while out of the seat), but some people report interesting gains.

Either that, or dont train more, just train properly. And invest in a wind trainer.

[FreaK]

[The "dead spot" concept and its relative "pedaling in circles" has no scientific foundation. In fact, Dr. Coyle in a peer-review study found quite the opposite, much to his surprise.

that's pretty nebulous. and essentially useless. It would not have been so had you for instance provided a link, or even mentioned who the heck Dr. Coyle is. For all anyone knows you just made i t up because you think rotor cranks look funny. .... not to be a dick or anything.

[ScienceIsCool]

I think these Rotor cranks are a bit dubious... When thinking about efficiency, you really have to think about efficiency of what? The drivetrain? No, I don't think it improves that. The hysteresis losses of the chain, cogs and chainrings wouldn't change.

Does it improve the efficiency of the engine? Efficiency of most motors is dependent on the load and rpm. Let's say 80% efficient at 60 rpm and 1000 N.m and 83% efficient at 100 rpm and 600 N.m for example. In this particular case, the output power is the same (1000 W), but the efficiency is better at 100 rpm.

In the case of a person, efficiency also depends on what part of the rotation phase you are in. But so does the load. Very complicated. In any case, you would want to spend more time at the most efficient loads and speeds in order to improve overall efficiency for a given speed. The relationship is so complex (a function of angle, load, output power, rpm) that I wouldn't be inclined to believe any claims until I saw a lot of clinical studies. It could also vary from person to person and depend on a host of physiological factors. You could write a PhD thesis on this for sure.

John Swanson

[Shallowhal]

I has a try of some of these at the London cycle show and I also know of a high mileage triathlete who uses them. Personally, I did notice the difference in riding style, whether it would make a huge difference to me on the open road is debatable.

I think everybody is thinking of efficiency meaning more power which to my mind is incorrect for these. The efficiency is in the continous pedal action. Likening it to a car engine, if you have a dead spot in your cycling rotation, its like revving an engine then lifting off, revving, lifting off etc. The lifetime and wear of your engine will be far better at constant revs. Somebody riding Rotor cranks will be less likely to tire out as quickly as when not riding them....but there again you're dragging the extra weight

[John979]

[The "dead spot" concept and its relative "pedaling in circles" has no scientific foundation. In fact, Dr. Coyle in a peer-review study found quite the opposite, much to his surprise.

that's pretty nebulous. and essentially useless. It would not have been so had you for instance provided a link, or even mentioned who the heck Dr. Coyle is. For all anyone knows you just made i t up because you think rotor cranks look funny. .... not to be a dick or anything.

Sorry, I presume most know of Dr. Coyle:

The Doctor

Here is the specific paper:

http://www.edb.utexas.edu/coyle/pdf%20library/(40)%20Coyle,%20Feltner%20et%20al,%20Physiological%20and%20biochemical%20determinants%20of%20elite%20endurance%20cycling%20performance,%20Med%20and%20Sci%20in%20Sports%20and%20Exercise,%2023,%2093-107,%201991.pdf

Sorry you must cut and paste but the long URL is messing up the WW webserver.

[ergott]

[The "dead spot" concept and its relative "pedaling in circles" has no scientific foundation. In fact, Dr. Coyle in a peer-review study found quite the opposite, much to his surprise.

that's pretty nebulous. and essentially useless. It would not have been so had you for instance provided a link, or even mentioned who the heck Dr. Coyle is. For all anyone knows you just made i t up because you think rotor cranks look funny. .... not to be a dick or anything.

Sorry, I presume most know of Dr. Coyle:

The Doctor

Here is the specific paper:

http://www.edb.utexas.edu/coyle/pdf%20library/(40)%20Coyle,%20Feltner%20et%20al,%20Physiological%20and%20biochemical%20determinants%20of%20elite%20endurance%20cycling%20performance,%20Med%20and%20Sci%20in%20Sports%20and%20Exercise,%2023,%2093-107,%201991.pdf

Sorry you must cut and paste but the long URL is messing up the WW webserver.

Fix this with tinyurl.com please. It makes reading this thread impossible.

-Eric

[mike]

hi, bo! i've owned rotor cranks and rotor q rings. i highly recommend the q rings. the rotors are heavy, but they will make you go faster at least in a time trial. i didn't like them when riding in a group. it made me feel slower in spinning when i really needed to. the q rings are much ligher, only 155 grams for a set of 53/42 rings.....

the rotors were 1200 grams complete (ti version).

mike

[gtingley]

Hi Guys,
I was thinking to maybe go to the Rotor crank for next season, I currently run a Shimano Ultegra 9 speed because my other 3 FSA Superlights broke this season!! I'm really tired of it!! Now because I play icehockey in the winter and I can't train as much as my concurrents I want to make my trainings as efficient as possible, I already bought a Powertap SL and now I was aking myself or the ROTOR crank is worth the extra weight (I don't really mind the weight when I have more efficient trainings) and if it is really an advantage? Can you guys help me out?
Thanks,

Hi Bo,

Many people have asked us what the real difference in performance and functionality is between Rotor cranks and Q-Rings since launching the Q-Rings line.

Q-Rings were designed to emulate the biomechanics of Rotor cranks, without the independent crank arm movement. This way you receive some of the benefits of the Rotor Cranks for a lower price tag. Both systems orient the maximum effective gear ratio in approximately the same position, a few degrees past the horizontal, in order to benefit from both muscle strength and leg inertia.

Both Q-Rings and Rotor cranks can be adjusted for different riding styles (standing sprinting or seated spinning, for example), bike geometry and terrain requirements. Q-Rings cannot not apply the same degree of variance in effective chainring diameter as Rotor cranks do, as this variance applied to two legs simultaneously would effect the cyclists spin negatively.

The advantages of Q-Rings, in general:

-Makes pedalling more efficient, and climbing much easier.

-Reduce lactic acid level production and reduces heart rate demands.

-Low weight.

-Simplicity.

-No extra pivots and bearing races, so maintenance is zero.

-Less intense dead point than standard chainrings.

The disadvantages compared to Rotor Cranks:

-The Dead point is not eliminated: only it's intensity is reduced.

-Biomechanical gains are less than those of Rotor Cranks.

[asphaltdude]

Question: Even if there is such a thing as a 'dead' spot..... now would that be a problem during submaximal efforts???? One might look at is as a phase of recovery in the pedaling cycle....

[STATO]

your legs still go over tdc and bdc but what this does is ensures both legs arnt 'resting' (as you put it) in that dead spot at the same time, so one leg is always on the power. yes you can push through tdc and bdc on normal cranks so your never really resting but you can on rotors as well, which is where the advantage is, everything a normal crank does and more.

Rich
(not a user but id love a set for my mtb if i could afford them)

[f.gump]

Question: Even if there is such a thing as a 'dead' spot..... now would that be a problem during submaximal efforts???? One might look at is as a phase of recovery in the pedaling cycle....

Exactly my feeling.