Effects of the Rotor Pedalling System on the Performance of Trained Cyclists During Incremental and Constant-Load Cycle-Ergometer Tests
http://www.thieme-connect.com./ejournals/abstract/sportsmed/doi/10.1055/s-2004-820941
FYI.
Ouch. A couple of questions: Why did they restrict cadence, rather than let the cyclists use their own? Do the Rotor Crank advocates require some adaptation period before benefits such as those tested for would show up?
Perhaps this is just another example of the “no free lunch” principle. In this case, you can’t get extra power from nowhere.
That isn’t true. Everybody knows that rotorcranks save you 2 minutes over a 40k, or 3 seconds a kilometer.
Just wait till jan ullrich gets ahold of a set; the low cadence poster child will win the tour by a very healthy margin, all he has to do is cough up 700 bucks for rotorcranks.
*Why did they restrict cadence, rather than let the cyclists use their own? *
Maybe the testers did not understand cadence Do the Rotor Crank advocates require some adaptation period before benefits such as those tested for would show up?
Absolutely. With zero adaptation time and only 80 minutes total on the system, these are typical results. Unfortunately the testers did not understand that there is an adaptation period. I have seen this test before, no real news here. I suggest 200-300 miles of adaptation before competition, let alone any “testing”.
There is no Free Lunch, only an efficient drivetrain, adaptation time and hard work will make a rider faster. Rotor helps by removing the dead point and allowing the cyclist to “permanent push” down on the cranks. More efficient, lower lactate accumulation levels and lower HR for the same wattage output.
WOW… I’m so surprised… NOT…
"2. Regardless of whether they do or not, the study included both habitual users and non-users. No significant differences were found between these two groups, implying that adaptation is not helpful. "
Where does is say habitual users? I see ten total, five trying Rotors, five not
Have you read the study in its entirety? By “Rotor users”, did they explicitly state that the trained cyclists were not, in fact, trained users of RCs, or are you just guessing?
Eliminates the dead point, lowers your lactate levels, allowing you to ride an average of 2 minutes faster per 40k.
Reminds me of a joke: two guys are sitting in a bar, when one spots Bill Gates walk in. He says to the other guy “Congratulations! On average, we’re millionaires!”. Your statistic is worthless without saying who went into that average. I’ll bet you can’t say (and provide data to back up) "trained cyclists will ride an average of 2 minutes faster per 40k). But I digress…
the test does state the following
“Ten cyclists (5 Rotor users and 5 non-users; age (mean ± SD): 22 ± 5 y; VO2max: 69.5 ± 5.1 mL · kg-1 · min-1) volunteered to participate in the study”
How do you respond to that?
Does that mean five used Rotors in the test, and five did not?
Half the group were adapted users: Subjects
After giving their written informed consent, ten trained male endurance (mountain bike or road) cyclists were selected for the investigation. Five of them had never used ROT before participating in this study whereas the other five had been using this new system during both training and competition from the previous 8 - 9 months (since the start of the season, in the previous fall). Subjects’ mean (± SD) age, height, and mass were: age: 22 ± 5 y, 177 ± 8 cm and 67.5 ± 9.5 kg, respectively. Subjects’ VO2max (higher mean for both incremental tests performed by each subject as explained below) was 69.5 ± 5.1 mL · kg-1 · min-1. The institutional research ethics committee (Universidad Europea de Madrid) approved the study.
Cadence discussed here: Study protocol
On four separate days during the month of July, all ten subjects performed two incremental tests and nine of them (four ROT users and five non-users) performed two 20-min tests at constant power output (PO). Both types of tests were performed with CON and ROT following a counter-balanced, cross-over design. The same cycle-ergometer (Monark, 818 E, Varberg, Sweden), that was equipped with either ROT or CON crank systems, was used during all the tests. An imposed crank rate of 75 rev · min-1 was used during all tests. This cadence ranges within the normal limits (70 - 90 rev · min-1) of preferred cadence in road cyclists during actual racing 12]]. A cadence of 75 rev · min-1 has also been used in previous research with trained cyclists that were tested with the same cycle-ergometer as here 16]]. The length of the pedal cranks was 172.5 mm for all subjects during all tests, and clip-on pedals were used. Each test was separated from each other by a 24-h period during which the subjects refrained from hard physical activity. Each subject performed his tests at the same time of the day. Each test was preceded by a 10-min warm-up period at a PO of 70 W with either CON or ROT system. All the testing sessions were performed under similar environmental conditions (20 to 24 °C, 45 to 55 % relative humidity).
nope, i actually thought that might be it, but it’s not.
Here’s how i read it;
All 10 riders were tested using rotorcranks and using normal cranks. 5 of those 10 riders came into the test as rotorcrank users, and 5 came into the test as users of only regular cranks.
(to rotors credit, it doesn’t say how long the 5 rotor users had been riding rotors beforee the test, but seeing as how the addaptation time is very short, i imagine they were all adapted)
Gary,
This actually seems like a reasonably designed study to see if Rotors actually provide any benefit.
I believe there may very well be a Rotor benefit, although I believe it is probably small. It is much more difficlt to design a study that shows benefit to statistical significance when the benefit is small. This requires either large numbers of subjects or a long period of testing.
If Rotors do provide a benefit it should be possibe to design a study to show and prove the benefit. How would you (or someone at Rotor who understands study design) design the study? Even if you have to pay to get it done right, at least then you are only dealing with the “bias” issue and not negative test results.
Frank
My own personal belief is that lab/ergo tests are probably not well suited for testing of the system, field, or race testing would be a better solution. Regulation point set up is also important. I did not read in the test where the points were set, this can have a very significant impact on the results.
Although we know what Rotors provide, and how they work, testing is another issue. We have had very positive feedback from athletes who state that their performance has significantly improved, independant of lab testing, after 1-3 months of use.
I know of several pro and elite riders on this board who can attest to the benefits, so they do in fact work.
"Although we know what Rotors provide, and how they work, testing is another issue. We have had very positive feedback from athletes who state that their performance has significantly improved, independant of lab testing, after 1-3 months of use.
I know of several pro and elite riders on this board who can attest to the benefits, so they do in fact work. "
How do you know what they provide? How do you know the “significant” improvement wasn’t due to shaking up the users training a bit? As the slowtwich mantra goes, anecdotal evidence does not equate to fact. I guess many of the same arguments that are used time and time again against Frank can be applied here.
I know because the athletes using them told me that they are faster on the Rotors. And, I know because I am faster on Rotors as well.
Anecdotal evidence may not equate to fact, but in the case of the several satisfied Rotorized athletes out there, very compelling.
I am not a scientist, but I have been working hard to bring real world field testing to the table. I am designing a test right now.
Pooks wrote: "I guess many of the same arguments that are used time and time again against Frank can be applied here. "
Not quite the same arguments because the only study published thus far on the PC’s did show statistically significant benefit. So, it is then necessary to bash the study rather than there is no study.
Two questions:
-
Was the 20 minute testing period long enough to see a significant benefit? I mention this because I do a course with two 29 mile loops and have noticed a small time drop on the second loop. (I’ve only done three 58 mile rides with the rotorcranks and the first one was actually slower than normal by about 4 minutes. On the second two my second half time dropped about 2 minutes each time. Also, from the first time I used them I did notice a lower average heart rate.)
-
Is a 10 person sample size large enough considering the short testing period?
I haven’t reached any firm conclusions about my RotorCranks, but they appear to promote efficiency over longer rides.
-Robert
I would like to know more about the test as well, to know which regulation point they are using, and how much adaptation/riding was done on Rotors prior to the test.
"I know because the athletes using them told me that they are faster on the Rotors. And, I know because I am faster on Rotors as well. "
Are you and these athletes faster when you ride Rotors (vs standard cranks), or faster on any crank since you began riding Rotors? So if you rode a bike with standard cranks, do you think you’d be faster than you were before you began using Rotors, or would you slide back to that level of performance? I guess my question is do you believe the presence of Rotors on a bike makes that bike faster, or using Rotors over time makes a rider faster?
In fact I don’t doubt that using Rotors has made you and your users faster. But I do have some doubt that it’s the mechanical design of Rotors that should receive the credit for the increase in speed. Rotors cause the muscle groups of the legs to be used/stressed differently than conventional cranks, and I’d expect some level strengthening to result. I wonder if it’s this change that makes riders faster, and therefore faster on all cranks. The study referenced in this thread basically shows for a given rider there is no difference in performance between riding Rotors or normal cranks. But it does not claim, or even attempt to test, whether rotors provide some training benefit over time. If they do provide this, I’d expect that like any training method the body will adapt and the gains will become less and less significant over time.
I still think the cranks are interesting, I’m just not convinced their case is, as you say, very compelling.
gary claims 3 second improvement per kilo.
Over a 20 minute period, that should be an obvious difference.
The world kilo record is 58. something seconds. The olympic record is something like 1:02. Rotorcrank’s claimed benefits would make a kilo rider like bobby lea, who is rather mediocre by world standrads, into a world champion.