The importance of crank length to the cyclist.

[FrankDay]

The common denominator in the personal attacks is you, Frank. That's why you have been banned from nearly every cycling message board you have tried to pedal your GimmickCranks in.

If this is all you have to offer to this thread on crank length you make my point. I simply don't understand why you all think I am bothered by this stuff such that I might go away. I am quite comfortable in my knowledge and opinions which is what I try to discuss on these threads. If you actually have some facts to present that might bring me around to your view please present them. Either way, thanks for participating I guess.

 

[M Sport]

If this is all you have to offer to this thread on crank length you make my point. I simply don't understand why you all think I am bothered by this stuff such that I might go away. .....

I have posted pieces from various studies in this thread since 2011, I noticed one just circled back into discussion a couple of days ago. You are such an ignorant c<nt though you don't take any notice of what other posters may contribute, you just carry on with the sales pitch of your sh1thouse GimmickCranks and Freds that ride them.

You want a scientific discussion but don't want to do the study to prove your crack pot hypothesis.

 

[CoachFergie]

If this is all you have to offer to this thread on crank length you make my point. I simply don't understand why you all think I am bothered by this stuff such that I might go away. I am quite comfortable in my knowledge and opinions which is what I try to discuss on these threads. If you actually have some facts to present that might bring me around to your view please present them. Either way, thanks for participating I guess.

Hey we well know that snakes have thick skins. We are mearly here to remind the uninitiated that you have made these claims in the past, had them soundly discredited yet persist in repeating the lie.

We are not here for you, we are here for the people who want the gimmick and are not prepared to do their homework which currently shows that crank length is unimportant, pedalling technique is irrelevent and Gimmickcranks don't improve cycling performance even if you have suckered in a few names. Many products do that and guess what? The products still don't work.

 

[FrankDay]

I have posted pieces from various studies in this thread since 2011, I noticed one just circled back into discussion a couple of days ago. You are such an ignorant c<nt though you don't take any notice of what other posters may contribute, you just carry on with the sales pitch of your sh1thouse GimmickCranks and Freds that ride them.

You want a scientific discussion but don't want to do the study to prove your crack pot hypothesis.

Huh? I am more than willing to discuss the pros and cons of any study that anyone wants to post. In fact, that is the purpose of starting such threads, to hopefully learn from others who have "facts" I don't. And, of course, everyone following the thread would be able to judge the relative merits of the two or three sides of the argument, if there is one. Your problem it seems is you seem to take it personally if someone might have a different view than yours and you then decide it is more effective to call someone names than to try to make your point again or in a different way. Oh well, it is the internet.

 

[FrankDay]

You want a scientific discussion but don't want to do the study to prove your crack pot hypothesis.

The best science is independent science, look at all the studies done by the cigarette companies supposedly "proving" cigarettes are safe. I have done my study that lasted 9 months, that I feel substantiates my claims (in fact, it was this "study" that determined what the claims should be, at least regarding power) and I have yet to see any scientific evidence to suggest what I say to be wrong.

So, from a scientific perspective, it is pretty much impossible for me to "prove" my own hypothesis since I am, from a scientific perspective, a biased observer. Asking me to do so ignores scientific principles and anything I did would be, rightfully, severely criticized. It must be left up to others to prove or disprove my claims. No study involving part-time use and lasting only 6 weeks is adequate to do so as our claims are based on 9 months of exclusive use in mid level competitive cyclists.

 

[CoachFergie]

Asking me to do so ignores scientific principles and anything I did would be, rightfully, severely criticized. It must be left up to others to prove or disprove my claims. No study involving part-time use and lasting only 6 weeks is adequate to do so as our claims are based on 9 months of exclusive use in mid level competitive cyclists.

A very convenient dodge seeing no racing cyclist is going to stop racing for a 9 month period to exclusively try and change their pedalling technique. Like Noel's technique your product has no real world application.

Besides it has been pointed out repeatedly that physiological responses and adaptations occur in seconds and hours so a two week study would be more than adequate to test the hypothesis. If no improvements are found in 5-6 weeks then it's pretty well established your theories are unproven.

Any increase in power after nine months of Gimmickcrank use reflects the riding done in that time not the product.

 

[FrankDay]

Any increase in power after nine months of Gimmickcrank use reflects the riding done in that time not the product.

Ball in your court. Prove it.

 

[CoachFergie]

Ball in your court. Prove it.

I believe it is the person who makes the claim who should provide the evidence. A six week study of the lack of improvement training with a Gimmickcrank more than adequately supports my claim.

Ditto with crank length and pedalling technique.

Even if your data is biased we would still like to see it.

 

[FrankDay]

I believe it is the person who makes the claim who should provide the evidence. A six week study of the lack of improvement training with a Gimmickcrank more than adequately supports my claim.

Ditto with crank length and pedalling technique.

Even if your data is biased we would still like to see it.

No, the person who makes the claim is biased. In science, the way it is supposed to be practiced, it is the job of the independent researcher to prove or disprove anothers claim. It is fundamentally impossible for a 6 week study to disprove a 9 month requirement claim regardless of your belief. A 6 year study could do it but not a 6 week study.

Anyhow, how on earth do you explain the improvement of Phil Holman, a 10 year competitive cyclist at an improvement standstill, who suddenly improves his power about 30% in 7 months (enough to win a bronze medal at Worlds) after starting training on PowerCranks. Such an improvement is so large and so unexpected it simply is unbelievable it was due entirely to his having trained for another 7 months. Wonder how much improvement he had seen in 6 weeks? I suspect it was not very much, if any.

 

[CoachFergie]

Anyhow, how on earth do you explain the improvement of Phil Holman, a 10 year competitive cyclist at an improvement standstill, who suddenly improves his power about 30% in 7 months (enough to win a bronze medal at Worlds) after starting training on PowerCranks. Such an improvement is so large and so unexpected it simply is unbelievable it was due entirely to his having trained for another 7 months. Wonder how much improvement he had seen in 6 weeks? I suspect it was not very much, if any.

How did you arrive at a 30% improvement in power? Improvement from what; power from a individual pursuit he did 7 months prior to the power measured from his ride at Master's Worlds?

In a two week period we have seen local riders improve by up to 15 seconds between Regional champs and National Champs in a 2000m Pursuit. We had one rider do a 4:47 for 4000m and missing the National Qualifiying time came out and rode again the next day in similar conditions and went 4:39. Illustrates that even though his physiology changed little he was able to make pretty large improvements in performance in less than 24hrs.

Another rider rode 3:37 for 3000m in November on Adelaide (fast and hot) and two months later produced 60 more watts on Invercargill but only ride 3:34 illustrating that times are not the best indication of performance between competitions only within competitions. Also the rider started with the 2nd fastest 1000m but ended up 10th highlighting that power alone isn't the best indicator of performance and that pacing, aerodynamics, tapering, psychology, technique all play a part in performance so comparing times or powers between two events doesn't give the full picture.

Training is how most people make their improvements in performance

 

[FrankDay]

How did you arrive at a 30% improvement in power? Improvement from what; power from a individual pursuit he did 7 months prior to the power measured from his ride at Master's Worlds?

That is easy. He reported his best speeds from the prior season to after the current season "My pursuit pace for training improved from last years 30 mph to 32 mph this 
summer. My top speed improved from around 35mph to 38mph." and I went to analytic cycling.com and assuming everything else remained the same found out how much more power would be required to see those speed improvements. Turns out it was slightly different for the two speeds but about 30%, as I remember. You can do it. See what you get.

Training is how most people make their improvements in performance

Of course that is true. But, in this case we have a rider who was failing to improve with just more training who improve dramatically using the PowerCranks. These reports were posted in both the old Rec.sports.triathlon and rec.bicycles.racing groups. These are archived on google groups. I went back to see if I could get his progression. I have copied and reproduced his 4 reports here. You can see it took him 3 weeks of "immersion" training to just get back to his baseline power (report #1). At 5 weeks he still hasn't seen any aerobic power improvement but is starting to see some anaerobic power improvement and has seen some improved race results (again almost immersion training). (report #2) After 8 weeks of essentially immersion training he is now reporting that "My pedaling technique is now almost automatic and I now 
notice very little difference between the power cranks and regular ones." yet his aerobic power still hasn't changed much although he still sees improvement in his anaerobic power. (report #3) It isn't until his final report, after 7 months, that he is reporting his huge improvement. With this demonstrated time course it is totally unreasonable to expect a 6 week study involving minimal part-time use to demonstrate substantial improvement. For your edification here are the reports (they are too long for one post so I will post them in two parts)


PowerCranks Report #1
Mar 29 2000, 12:00*am
>Having previously stated that the Inventor's claims (Frank Day) were
>outrageous I proposed this test to him to as an opportunity to demonstrate
>their worth.
>Your comments, questions and opinions are welcome.
>Phil Holman

Well its week three and I've certainly had my ups and downs with the cranks. Two days ago I was decidedly "powerfully cranky" and not "cranking powerfully". Things have turned around though and today I bench marked a 30min workout at 400 watts on the trainer. For those familiar with the CatEye Cyclosimulator, the setting was at 3% grade with the fan switched off but still installed. In my estimate this reading is between 50 and 100 watts too high.

A couple of problems I've had that I've finally solved are:
1/ Although I was extending my time of continuous pedaling It was not becoming any easier and there was a definite lack of power. I was having great difficulty in pedaling over the top. What I finally figured out was, by pulling up, my ankles were flexing with my heel being raised. My leg was about 1" higher going over the top. I solved it by raising my seat 1/2 inch and the difference is like night and day.
2/ I normally like my shoes on the loose side. Pulling up resulted in my feet moving around in the shoe a lot. I now have to cinch them up a lot tighter. This was no big deal but something I never considered.
Power * * * * * * * * * Time * * * * * HR * *Cadence * *Gear * *Date

Miles 

400 w * * * * * * * * * *30 min * * * *140 * * *75 * * * * * 56/13 * 3/29/00 

250 

756 w (max) * * * * * N/A * * * * * * * * * * * * * * * * * * * * 56/13 
3/29/00
Its taken me almost 3 weeks to be able to pedal with a revised stroke at the power output I was doing a month ago. 
This may not sound significant to some but to me its quite an achievement. 
My heart rate of 140 is 10 beats lower than before and my cadence is about 
10 lower as well. Its naturally more comfortable to push and pull a bigger 
gear with a low cadence with this stroke. At this time I could not go any 
faster at a higher power output because my legs, especially pulling up, 
wouldn't let me. 
I still have to concentrate on the stroke but hope this will become 
automatic with more training. On rainy days I ride my rain bike without the 
cranks but I still pedal with the revised stroke just as if they were there.
Bottom line is .....3 weeks and we are even.

Phil Holman

PowerCranks Report #2
Apr 21 2000, 11:00*pm
This is report #2 from my training assessment of the Power Cranks For more info on the cranks see http://www.powercranks.com. It was the official start to the race season up here in the Pacific 
NW where I raced a crit on Saturday April 1st and a Road Race on 
Sunday April 2nd. 
In the crit which was a combined Masters 40+. I placed 2nd in 50+ and 
5th over all. I'm no crit racer. 
In the RR on Sunday which was a Pro 1,2 , I placed 9th. 
Significant is the fact that I used the pulling up technique when 
accelerating, bridging, taking a pull and finishing. More significant is the 
fact that in 10 years of racing the Volunteer Crit Season Opener this is my 
highest placing. Even more significant is the fact that as a Cat 2 for the 
last 3 seasons I have never placed in the top 10 in a pro 1,2, race. In both 
races there were people off the front but I managed to win both field 
sprints out of a chasing group. I attribute this to the pulling up 
technique. 
Since then I have had some technical problems with my training bike and 
haven't been able to achieve adequate mileage with the cranks even though 
I still incorporate the pedaling technique as much as possible. I have only 
managed to maintain my aerobic output from the previous report where 
it felt comfortable at an even lower cadence. See below.
Power * *Time * * * HR * *Cadence * *Gear * * * * Date * * * *Max
400 w * * 30 min * 140 * * *75 * * * * * 56/13 * * * * 3/29/00 * 756 w
400w * * *30 min * 150 * * *70 * * * * * 56/12 * * * * 4/22/00 * 745 w
Can anyone comment on the significance of the increased HR?
The last couple of weeks I have felt tired and maybe a little overtrained 
from an increase in workout intensity. 
Interestingly on the track I have noticed improvement in anaerobic 
output with the pulling up technique over last season. 
Experiencing difficulty in keeping up with the paceline when it reached 
30+ mph for the last 10 laps of a 30 lap workout, I returned next week 
with a 101 inch gear (94 inch previously) and had no problem. 
Riders familiar with track will know this is a monster gear for early 
season workouts but it felt as comfortable as last year at 94in with the 
pulling up technique I have acquired from training with the cranks. 
I also did some 800m intervals at 31/32 mph where previously 
I was maxed out at 30mph. On a roll, I figured I would see what my max 
speed is and managed to get up to 36mph. Comparing this with my max 
output on the trainer puts the trainer readout about 100watts too low at 
700/800 and 50/100 too high as previously determined at 300/400. 
With my training bike back in commission I will get back on track with more 
miles on the cranks over the next few weeks for the next report.
To summarize for report #2.....aerobic output maintained 

* * * * * * * * * * * * * * * * * * * * * * * * * *anaerobic output increased

 

[FrankDay]

Continuation of Phil Holman's Reports from rec.sport.triathlon and rec.bicycle.racing from 2000

PowerCranks Report #3
May 12 2000, 11:00 pm
The last 3 weeks of training have contained a period of a week or so where I was suffering from over training. I had to take it easy for that period of time to get my performance back. Prior to this episode I had an output of 500 watts on the trainer for 2 minutes (beating my previous best ever of 1-30) The trainer is fairly accurate at this power level, my best estimate is that its equivalent to at least 30 mph on the track. This last week I was glad to get back to my 400 watts for 30 minutes (HR 145). Most recent is a 2 1/2 minute 500 watts and a 15 minute 425 watts. This is continuing on the theme of improved anaerobic output while maintaining aerobic output. The period of taking it easy was made up of pedaling at higher cadences which has carried over into my recovery and is now more comfortable with the cranks.
Power Time HR Cadence Gear Date Max
400 w 30 min 140 75 56/13 3/29/00 756 w
400w 30 min 150 70 56/12 4/22/00 745 w
400w 30 min 145 85 50/13 5/10/00 751w
425w 15 min 156 90 50/13 5/12/00 -
The 50/13 gear I am now using is because I have mounted my training track 
bike to the trainer to be track specific. This is a 101 inch gear which I 
will gradually increase to my anticipated final gear of around 110 inches 
for the pursuit. My pedaling technique is now almost automatic and I now 
notice very little difference between the power cranks and regular ones.
The 2 1/2 minute at 500 watts is better than the goal I had set for my 2k 
pursuit training. I cannot attribute this to anything else but my training 
with the power cranks. My pedal stroke is smooth and even for the full 360 
degrees. I tend to over accentuate the pull-up for the first minute then 
balance between pulling and pushing for the second. The last 30 seconds was 
pure gutting it out where I even increased and maintained 520 watts. I'm not 
done with the cranks yet and will strive to improve even more for this time 
interval. 
Anaerobic gains are still eluding me and I don't know why. I have started 
out on a couple of training sessions at 450 watts and felt comfortable. 
However the lights started to fade after 5 or 6 minutes and I had to abort 
to 10 minute intervals instead.
In Summary Anaerobic output Remarkable gains (>10%) 
 Aerobic output Maintained.

PowerCranks Final Report
Sep 20 2000, 11:00 pm
This will be my final report for 2000 having trained fairly consistently with the Power Cranks for the last 7 months.

For those not familiar with my training and reports, I was a skeptic of the claims made by their inventor Frank Day and volunteered to train with them and report on my findings. The cranks work by going out of phase if you do not pull up on them (each crank has its own freewheel so to speak).The constant feedback forces the rider to modify their pedal stroke and always provide positive torque to the cranks with both legs.

My final conclusion is that they worked for me. 
I've been a life time sports and fitness enthusiast and have been cycling 
competitively for the last 10 years. I'm 50 years old so for me to see the 
improvement in my performance over the last several months has been 
totally awesome. 
Winning a Bronze Medal at World Masters Track has been a real kick. Its been 
almost 3 weeks and I'm still grinning. 
The following is a list of observations/hints that I discovered when using 
the cranks and may be useful to some in obtaining maximum benefit.
1/ Pulling up on the cranks is best achieved at a lower cadence (80 rpm). At 
this speed the hamstrings and hip flexors get a good workout but expect it 
to take a couple of weeks for these muscles to be strong enough for you 
to pedal continuously for a couple of miles at a time.
2/ Modification of ones pedal stroke with increased pull-up tends to 
diminish the magnitude of the downstroke. Someone actually reported 
that they deteriorated overall after using the Cranks. 
This is noticeable when climbing out of the saddle or trying to 
accelerate quickly with a pedal stomp. What I did to counteract this was to 
do a few 10 minute sessions of climbing a week using my quads only to 
maintain their power and strength.
3/ The Power Cranks require good discipline to use as they are more awkward 
to get in and out of the pedals and are less user friendly when freewheeling 
and riding in traffic. I choose a 10 mile loop with light traffic and a 
cycle lane to do most of my training. 
It had several good climbs in it and was ideal. 
It may be difficult to ride them on a group ride especially if you are out 
with a bunch of hammer heads. 
Make sure you maintain this kind of ride in your workout program if it is 
already there.
4/ I did notice increased leg strength after using the cranks not only when 
riding but also when walking around. I seemed to have more spring in my step
5/ My training sessions got faster especially intervals on the track. 
My pursuit pace for training improved from last years 30 mph to 32 mph this 
summer.
6/ My top speed improved from around 35mph to 38mph.
7/ Although I didn't ride any TTs this year (missed Nats with broken arm) my 
30min power workouts on the trainer improved to equal my best ever without 
having to do my killer TT intervals.
8/ My AT heart rate improved from my usual (low 150s) to 160. 
160 was normally my max yet I was able to sustain it for 30 mins......wow.
9/ Most good weeks I put in around 100 miles with the cranks. After several 
weeks I noticed that I was automatically pedaling with the same action on my 
race, rain and track bikes with regular cranks.
10/ The sound of my trainer has gone from whir....whir....whir....whir to 
....whirrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr.
I look forward to continue training with the cranks in the off season and 
hope to do a PR in the 40k TT next season. Masters Nats in is in my 
home state (WA) for 2001. 


Regards

Phil Holman

 

[CoachFergie]

That is easy. He reported his best speeds from the prior season to after the current season "My pursuit pace for training improved from last years 30 mph to 32 mph this 
summer. My top speed improved from around 35mph to 38mph." and I went to analytic cycling.com and assuming everything else remained the same found out how much more power would be required to see those speed improvements.

So you didn't actually measure power in the IP at any point. This was an outdoor track where conditions can vary hugely within a session let alone from day to day.

Did he use same wheels, gearing, was the wind different, temperature, clothing, aero helmet, etc.

BS argument really. I know my rider improved 60 watts in two months because we measured it with a SRM that was checked for calibration before both rides.

 

[CoachFergie]

Watts estimated using a Cateye Cyclosimulator based on a combination of cadence and level of resistance so rather meaningless compared to a SRM.

I was testing the manufacturer claims of a shoe company using a powertap and the variance in power was actually a reflection of the type of trainer I was using. Biting the bullet and purchased an SRM so I get it right next time.

That's some pretty bad science there Frank.

So still no real evidence that your product has an effect on performance.

While numerous studies of various training methodologies have seen dramatic changes in performance in two weeks or less.

 

[FrankDay]

I know my rider improved 60 watts in two months because we measured it with a SRM that was checked for calibration before both rides.

Could you give more details as to the beginning wattage and ending wattage and when this occurred in the training cycle? 30 to 32 mph represents over a calculated 80 watt improvement (408 to 490 watts, about 20%) and 35 to 38 mph increase represents a calculated 168 watt improvement (633 to 801 watts, about a 27% improvement). I am glad your rider saw a 60 watt improvement but that doesn't sound that large compared to a calculated 168 watt improvement. And, it sounds like my technique may somewhat underestimate his real power (or over estimate his aerodynamic shape) because he wrote this: "The trainer is fairly accurate at this power level (500 watts), my best estimate is that its equivalent to at least 30 mph on the track." You may not like the way I calculated that power improvement but since Holman was a PC skeptic and took the challenge to prove my claims to be false I suspect he was not interested in doing these tests on days that made them look better than they were. If one doesn't have SRM data one has to do something to estimate changes. Because these tests were run by the same person on the same track it seems these are reasonable estimates as to his power improvement.

So, how about some more details on that "measly" 60 watt increase your rider saw?

 

[CoachFergie]

Could you give more details as to the beginning wattage and ending wattage and when this occurred in the training cycle?

November 2012 at Oceania Track Cycling Champs in Adelaide. Rider was part of the NZ U19 Track Cycling Team.

February 2013 at New Zealand Elite/U19 Track Cycling Champs.

So both priority events and rider aspired to perform and prepared for both.

30 to 32 mph represents over a calculated 80 watt improvement (408 to 490 watts, about 20%) and 35 to 38 mph increase represents a calculated 168 watt improvement (633 to 801 watts, about a 27% improvement).

But you are holding everything else constant. You would think a former Engineer would know better than that considering it was outdoors.

I am glad your rider saw a 60 watt improvement but that doesn't sound that large compared to a calculated 168 watt improvement.

A wild ar*e guestimated 168 watt improvement. Again you would think a former engineer would know better.

60 watts if everything was held equal would mean a 27 second improvement in the riders 3000m time which would be a World Record by 3 seconds. So as I said certainly more at play in terms of performance than just power or average speed.

And, it sounds like my technique may somewhat underestimate his real power (or over estimate his aerodynamic shape) because he wrote this: "The trainer is fairly accurate at this power level (500 watts), my best estimate is that its equivalent to at least 30 mph on the track."

Laughable! The Cateye makes a guess on power and does not take into account tyre resistance or changes in friction as the roller heats up under use. Again you would think a former engineer would know this.

You may not like the way I calculated that power improvement but since Holman was a PC skeptic and took the challenge to prove my claims to be false I suspect he was not interested in doing these tests on days that made them look better than they were.

I don't think a 10 year old with a limited understanding of cycling or science would like your guesstimation of power.

If one doesn't have SRM data one has to do something to estimate changes. Because these tests were run by the same person on the same track it seems these are reasonable estimates as to his power improvement.

Did the equation include the temperature for each effort, the wind speed for each effort, the equipment used, the gearing used, the clothing used, did the pacing strategy for each ride stay the same etc. 1000s of confounding variables that show how laughable your claims are. Again you would think a former engineer would know better.

So, how about some more details on that "measly" 60 watt increase your rider saw?

At least I know mine is real. Yours is imagined, and done so badly. I wonder about the quality of the School that taught you engineering.

 

[42x16ss]

But, the main benefit of going shorter for most is not more power but the ability to get better aerodynamics for the time trialist. How on earth do you do that by "simply getting a powertap wheel and testing power output on one of your bikes with adjustable length cranks."

Further, isn't that essentially what Martin did in his study? It would appear that if he had 2-3 times more subjects in that study he would have reached a statistically significant difference between 145 and 170, what would you be saying then? Anyhow, why do I need to repeat Martin's study with N=1?

We are all different when it comes to how much "evidence" it takes to make us change what we are doing. The lack of convincing evidence either way is all the more reason to discuss a subject. Perhaps such discussions will get some researchers off their bottoms and get some good evidence to definitely answer the question. Until then those who are unwilling to experiment on themselves to see what is best for them are "guessing" as to what is best for them.

Ok then, maybe I made an oversimplification. Why not get a track bike, with a powermeter and adjustable cranks, a HRM, then book some time in the velodrome over several weeks/months.

You will have conditions that are as close to identical as possible and an accurate gauge of distance. From here you should be able to get a good idea of how crank length can effect speed, how power delivery changes with crank length and if heart rate intensity changes with crank length as well.

An experiment like this could really make or break your claims Frank. Why not give it a go?

 

[FrankDay]

Ok then, maybe I made an oversimplification. Why not get a track bike, with a powermeter and adjustable cranks, a HRM, then book some time in the velodrome over several weeks/months.

You will have conditions that are as close to identical as possible and an accurate gauge of distance. From here you should be able to get a good idea of how crank length can effect speed, how power delivery changes with crank length and if heart rate intensity changes with crank length as well.

An experiment like this could really make or break your claims Frank. Why not give it a go?

I don't need to although now that I have a preproduction model of the iCranks I will be able to do this on the Velotron (as I test to see how the iCrank calibration changes with crank length) I will do so and compare power vs HR vs crank length (and be able to look at how the pedal forces change also). Further, one of my elite athletes has his PowerCranks mounted on an SRM hub such that we will be able to do the same validation on an SRM without any chain losses (although I think the Velotron is a little more accurate).

That having been said, this experiment has been done many times by customers who have listened to us and tried this experiment (perhaps not on a track but usually with a power meter). Most (but not all) have decided to stay short and when I hear about the results I regularly post most of those anecdotal reports here. Plus, isn't this essentially what Martin did? Regardless of these many reports (and the Martin study) I haven't seen any of these "making or breaking" the bias of the unbelievers who have never done this experiment themselves.

 

[FrankDay]

At least I know mine is real. Yours is imagined, and done so badly. I wonder about the quality of the School that taught you engineering.

Fergie, that report was made by an engineer (worked at Boeing if I remember correctly) who, before he got on the cranks, was just as negative regarding the potential as you. Not everyone has the ability to measure power down to the nanowatt (as if that is important). His reports are his reports, attempts to relate to the group his experience and analysis. My analysis was an attempt to put the overall speed improvements he reported in his final report into perspective for those who do not understand that power generally varies with the CUBE of the speed. Ignore it if you choose.

 

[42x16ss]

I don't need to although now that I have a preproduction model of the iCranks I will be able to do this on the Velotron (as I test to see how the iCrank calibration changes with crank length) I will do so and compare power vs HR vs crank length (and be able to look at how the pedal forces change also). Further, one of my elite athletes has his PowerCranks mounted on an SRM hub such that we will be able to do the same validation on an SRM without any chain losses (although I think the Velotron is a little more accurate).

That having been said, this experiment has been done many times by customers who have listened to us and tried this experiment (perhaps not on a track but usually with a power meter). Most (but not all) have decided to stay short and when I hear about the results I regularly post most of those anecdotal reports here. Plus, isn't this essentially what Martin did? Regardless of these many reports (and the Martin study) I haven't seen any of these "making or breaking" the bias of the unbelievers who have never done this experiment themselves.

Cool, why don't you request the customer's power files? The data could really back up your marketing. The Martin study was relatively limited, as Hamish and others have discussed. With your customer base (if it is what you are suggesting) you could potentially compile mountains of data...

I also suggested the velodrome so that you can get some idea of the effect crank length can have on overall speed at a given power from an aero point of view.

 

[FrankDay]

Cool, why don't you request the customer's power files? The data could really back up your marketing. The Martin study was relatively limited, as Hamish and others have discussed. With your customer base (if it is what you are suggesting) you could potentially compile mountains of data...

I also suggested the velodrome so that you can get some idea of the effect crank length can have on overall speed at a given power from an aero point of view.

I understand. Actually, we did get some power files and I thought I posted them here, but maybe the guy asked us to keep them to ourselves - I will have to check. Anyhow, he is an elite coach out of Italy and just didn't believe that short cranks could be powerful. I think he tested 175, 165, and 155 and couldn't believe the results (I think the 155 was a little higher).

I understand the Velodrome and aerodynamics thing but this can now be done on a regular bike with a power meter using the Chung technique.

Anyhow, I firmly believe this is something that each person needs to experiment with themselves and see what is best for them. The fact that your bike came with 170 cranks is not good evidence that is the best crank length for you. Neither I nor Fergie, nor you, nor anyone else can predict what anyone else will do. I think I said that in the first post in this thread. If not, I say it now.

 

[FrankDay]

Actually, we did get some power files and I thought I posted them here.

Found them.
If the link doesn't work the post was on 10/1/12 and I find it on page 169 on my screen
http://forum.cyclingnews.com/showthread.php?p=1040739&highlight=excaliber#post1040739

 

[CoachFergie]

Fergie, that report was made by an engineer (worked at Boeing if I remember correctly) who, before he got on the cranks, was just as negative regarding the potential as you. Not everyone has the ability to measure power down to the nanowatt (as if that is important). His reports are his reports, attempts to relate to the group his experience and analysis. My analysis was an attempt to put the overall speed improvements he reported in his final report into perspective for those who do not understand that power generally varies with the CUBE of the speed. Ignore it if you choose.

I will bear that in mind the next time I fly on a Boeing. Bit like the MIT grad who claimed a FTP (60min test) improvement from a rollers based test that was higher than his 20min power from a uphill time trial. Turns out the MIT (isn't that a big deal in the US???) grad hadn't calibrated his power meter. You would expect a MIT grad would know better.

I feel it is you who does not understand what power is and how depending on the environment and mechanical considerations that speed may have no relationship with power. Again you would think a former engineer would know better.

 

[FrankDay]

I will bear that in mind the next time I fly on a Boeing. Bit like the MIT grad who claimed a FTP (60min test) improvement from a rollers based test that was higher than his 20min power from a uphill time trial. Turns out the MIT (isn't that a big deal in the US???) grad hadn't calibrated his power meter. You would expect a MIT grad would know better.

I feel it is you who does not understand what power is and how depending on the environment and mechanical considerations that speed may have no relationship with power. Again you would think a former engineer would know better.

LOL. MIT actually does have a pretty good reputation here and deservedly so, I think. You don't want to know what that MIT grad thinks of your abilities. You misconstrue and misrepresent almost everything but I think it would be better to stay with the actual data brought up in this thread than personally attack another person not here to defend himself.

 

[CoachFergie]

LOL. MIT actually does have a pretty good reputation here and deservedly so, I think. You don't want to know what that MIT grad thinks of your abilities. You misconstrue and misrepresent almost everything but I think it would be better to stay with the actual data brought up in this thread than personally attack another person not here to defend himself.

Well like your personal attacks on us I don't really care about your opinion or his. If we stick to the facts then crank length isn't all that important. The only person who says it is is the person with a history of starting Spam threads and has an adjustable crank length product to sell.