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  #1781  
Old 02-10-13, 21:44
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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.
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  #1782  
Old 02-10-13, 21:59
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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.
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  #1783  
Old 02-10-13, 23:57
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Originally Posted by CoachFergie View Post
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? :-)
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  #1784  
Old 02-11-13, 00:47
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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.

Quote:
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.

Quote:
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.

Quote:
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.

Quote:
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.

Quote:
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.

Quote:
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.
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Last edited by CoachFergie; 02-11-13 at 00:51.
  #1785  
Old 02-11-13, 01:54
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Originally Posted by FrankDay View Post
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?
  #1786  
Old 02-11-13, 02:11
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Originally Posted by 42x16ss View Post
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.
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Last edited by FrankDay; 02-11-13 at 02:13.
  #1787  
Old 02-11-13, 02:25
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Originally Posted by CoachFergie View Post
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.
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Last edited by FrankDay; 02-11-13 at 02:29.
  #1788  
Old 02-11-13, 02:44
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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.

Last edited by 42x16ss; 02-11-13 at 02:51.
  #1789  
Old 02-11-13, 03:01
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Originally Posted by 42x16ss View Post
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.
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  #1790  
Old 02-11-13, 03:10
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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/showthr...er#post1040739
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