The importance of crank length to the cyclist.

[FrankDay]

On an outdoor track, way off. Even on an indoor track temperature variations make a huge difference. !

Temperature variations make a HUGE difference? Perhaps you could give an example of what you mean here. Thanks in advance.

 

[CoachFergie]

NZ IP Champs. Qualifying round, 20 degrees on in the track. Rider went X amount power (not my rider so can't mention power) and in the final went the same power but with the conditions warming up to 28 degrees on the infield for the same power he went 2 seconds faster for 3000m. That is over 1% faster in 10 hours. That is huge.

But your dodging the issue which is of measurement. You have made a claim and your only evidence is a potential result in a race comparing two data points a year apart. Not very scientific.

 

[Martin318is]

Well, one certainly doesn't need a PM to make the decision. All one need do is ride a known loop on a calm day and if there is a big difference it should be apparent. If there isn't then I would buy the cheapest one.

I'll bet that the second helmet is the one you select if you do this.

Unless there is a change in wind between efforts, you will virtually always do a faster and more consistent ride in the second session because you know what to expect and what you are capable of because you just did it. Even if you hide the speed display from the rider (and you'd have to) pacing will be smoother and higher meaning a faster time.

 

[Martin318is]

Actually Frank - I have a simple question.

If your athlete produces a slower time this year than he did last year will you - ignoring other circumstances in the event - consider that conclusive proof that short cranks are inferior to standard length cranks?

 

[FrankDay]

NZ IP Champs. Qualifying round, 20 degrees on in the track. Rider went X amount power (not my rider so can't mention power) and in the final went the same power but with the conditions warming up to 28 degrees on the infield for the same power he went 2 seconds faster for 3000m. That is over 1% faster in 10 hours. That is huge.

But your dodging the issue which is of measurement. You have made a claim and your only evidence is a potential result in a race comparing two data points a year apart. Not very scientific.

Ugh, you cannot know his position was the same for those two efforts. Nor, are you telling us his effort was even for the two efforts. Temperature only affects air density and it is possible barometric pressure changed in the interim due to local weather conditions or changes in humidity such that temperature may not have been the only variable in your anecdote. No need to give anecdotes, the difference is calculable using known science. It is "easy" to compensate for temperature effects using mathematics even without a GM. Show how 8 degrees changes the barometric pressure then plug that change in at analyticcyling.com and get back to us.

 

[FrankDay]

Actually Frank - I have a simple question.

If your athlete produces a slower time this year than he did last year will you - ignoring other circumstances in the event - consider that conclusive proof that short cranks are inferior to standard length cranks?

Of course not. Lots of stuff can slow you down. I think a single anecdote is hardly "proof" of anything.

Would you consider a single incident like that "proof" of anything?

 

[FrankDay]

I'll bet that the second helmet is the one you select if you do this.

Unless there is a change in wind between efforts, you will virtually always do a faster and more consistent ride in the second session because you know what to expect and what you are capable of because you just did it. Even if you hide the speed display from the rider (and you'd have to) pacing will be smoother and higher meaning a faster time.

Why? If I ride my "normal" loop, something I do almost every day I am not sure second ride familiarity offers any advantage. Further, both efforts don't have to be done on the same day and I would prefer to do several efforts with each helmet rather than leave it to a single trial. I would probably also want to compare it to a non-aero helmet to see if there is any advantage to me in getting either helmet. People have won IM Hawaii using non-aero helmets. I would want to do a similar trial even if I were using a GM to make the decision. A single trial is not particularly reliable regardless of the technique one is using.

 

[CoachFergie]

Ugh, you cannot know his position was the same for those two efforts. Nor, are you telling us his effort was even for the two efforts. Temperature only affects air density and it is possible barometric pressure changed in the interim due to local weather conditions or changes in humidity such that temperature may not have been the only variable in your anecdote. No need to give anecdotes, the difference is calculable using known science. It is "easy" to compensate for temperature effects using mathematics even without a GM. Show how 8 degrees changes the barometric pressure then plug that change in at analyticcyling.com and get back to us.

So results can change even if there is no difference in performance. Fancy that.

 

[FrankDay]

So results can change even if there is no difference in performance. Fancy that.

No, performance can change even when there is no difference in power.

 

[CoachFergie]

Of course not. Lots of stuff can slow you down. I think a single anecdote is hardly "proof" of anything.

Would you consider a single incident like that "proof" of anything?

So why did you raise this as evidence for the improvement in power from using a shorter crank?

 

[Tapeworm]

...But, aren't you advocating that cyclists should spend $1,000 or more for a device without actually knowing how much improvement they will receive for that investment?...

Hmmm Frank is right. You heard it here folks, don't buy Powercranks, you'll pay $1k for a device without knowing how much improvement you get for that investments

 

[FrankDay]

So why did you raise this as evidence for the improvement in power from using a shorter crank?

First, if you will go back to the post that started this thread you will find that an "increase in power" is not what I theorize as the major reason leading to a potential large increase in performance, but rather an improved aerodynamics. Therefore, the whole tenor of this thread is it may be possible to improve performance without increasing power by making this simple change.

Since in this instance the anecdotal evidence will come from a race that involves 28k ft of climbing. It might be possible that if he sees a small drop in power he might even see a slightly slower time but would still perform better on a relatively flat course. If his time is similar or faster I think one might reasonably conclude that very short cranks do not necessarily mean a big compromise in power. One must look at the entire picture when evaluating anecdotal evidence.

 

[CoachFergie]

Why? If I ride my "normal" loop, something I do almost every day I am not sure second ride familiarity offers any advantage. Further, both efforts don't have to be done on the same day and I would prefer to do several efforts with each helmet rather than leave it to a single trial. I would probably also want to compare it to a non-aero helmet to see if there is any advantage to me in getting either helmet. People have won IM Hawaii using non-aero helmets. I would want to do a similar trial even if I were using a GM to make the decision. A single trial is not particularly reliable regardless of the technique one is using.

Your the one bringing up the anecdotal evidence and in a previous post in this or the cleat position thread claim that the modification was better because the rider said it felt better.

My IP example is backed with power numbers (which I am not at liberty to share if I expect people to continue confiding these things to me), speed data , time data, temperature data, distance data, pacing data, position information (his position didn't change), tyre pressure etc. Heck knowing the rider in question I could tell you his motivation would have been equal between rides, what he ate that day and how much sleep he had the night before.

It's not an anecdote when one has all this valid and reliable data on hand.

 

[FrankDay]

Hmmm Frank is right. You heard it here folks, don't buy Powercranks, you'll pay $1k for a device without knowing how much improvement you get for that investments

The difference between us and a GM though is we offer a 90 day money-back guarantee. Not seeing improvement that is worth the cost then simply send them back and get your money back.

 

[CoachFergie]

No, performance can change even when there is no difference in power.

Maybe in imaginationland but how do you propose that someone can perform more work without doing any more work

 

[FrankDay]

Your the one bringing up the anecdotal evidence and in a previous post in this or the cleat position thread claim that the modification was better because the rider said it felt better.

My IP example is backed with power numbers (which I am not at liberty to share if I expect people to continue confiding these things to me), speed data , time data, temperature data, distance data, pacing data, position information (his position didn't change), tyre pressure etc. Heck knowing the rider in question I could tell you his motivation would have been equal between rides, what he ate that day and how much sleep he had the night before.

It's not an anecdote when one has all this valid and reliable data on hand.

LOL. an·ec·dote
noun, plural an·ec·dotes or, for 2, an·ec·do·ta [an-ik-doh-tuh] Show IPA.
1. a short account of a particular incident or event, especially of an interesting or amusing nature.

Having "reliable" data (even if you won't share it) only makes the anecdote more interesting. Doesn't change it into science.

I started these threads for the purposes of discussion, not as proof of anything.

Unless you can give us the actual power number, the power profile, and the actual atmospheric pressure during your anecdote it is worthless for making your point even if you did give us the data you won't give us.

 

[CoachFergie]

First, if you will go back to the post that started this thread you will find that an "increase in power" is not what I theorize as the major reason leading to a potential large increase in performance, but rather an improved aerodynamics. Therefore, the whole tenor of this thread is it may be possible to improve performance without increasing power by making this simple change.

Far better ways to improve aerodynamics than making expensive changes to equipment and involving dramatic changes to the position on the bike. New cranks, lifting the bars, shortening the stem, shunting the seat back and lifting it up.

Sounds like a solution in search of a problem. Hmmm where have we heard that before. Ah yes the cure to huge pedalling efficiencies we see in the peloton.

Since in this instance the anecdotal evidence will come from a race that involves 28k ft of climbing. It might be possible that if he sees a small drop in power he might even see a slightly slower time but would still perform better on a relatively flat course. If his time is similar or faster I think one might reasonably conclude that very short cranks do not necessarily mean a big compromise in power. One must look at the entire picture when evaluating anecdotal evidence.

Ahhhh so anecdotes are permissible if they support your claims.

"So Frank Day"

 

[CoachFergie]

The difference between us and a GM though is we offer a 90 day money-back guarantee. Not seeing improvement that is worth the cost then simply send them back and get your money back.

Do you refund the lost 90 days?

 

[FrankDay]

Maybe in imaginationland but how do you propose that someone can perform more work without doing any more work

Going faster (improving performance) does not necessarily require more power (doing more work). That is the part of this entire discussion you seem to be missing.

 

[FrankDay]

Do you refund the lost 90 days?

Nope. But, you don't have to wait 90 days to send them back. Send them back in a week if you don't like what you see.

 

[CoachFergie]

LOL. an·ec·dote
noun, plural an·ec·dotes or, for 2, an·ec·do·ta [an-ik-doh-tuh] Show IPA.
1. a short account of a particular incident or event, especially of an interesting or amusing nature.

Having "reliable" data (even if you won't share it) only makes the anecdote more interesting. Doesn't change it into science.

Valid and reliable. Which means my claims can be replicated and tested. The Everest Challenge is not reliable unless you can confirm the weather is the same, the bike is the same, the rider is the same, the competition is the same, the road surfaces are the same and the only variable that was manipulated was crank length and the associated positional changes.

I started these threads for the purposes of discussion, not as proof of anything.

There is no difference between this and any other Spam thread. Some baseless claims and a link to a site that conveniently sells you the solution to the problem you have suggested exists.

 

[CoachFergie]

Going faster (improving performance) does not necessarily require more power (doing more work). That is the part of this entire discussion you seem to be missing.

Staggering a person with your qualifications confuses a result based outcome (speed) with a performance based outcome (work performed). Speed can be achieved with no work at all if you point a bike downhill.

 

[CoachFergie]

Nope. But, you don't have to wait 90 days to send them back. Send them back in a week if you don't like what you see.

Either way is meaningless. A marketing gimmick is not evidence of a products effectiveness.

 

[Night Rider]

Nope. But, you don't have to wait 90 days to send them back. Send them back in a week if you don't like what you see.

Crossing the line, Frank. This isn't a classified forum.

But while you are talking about your own product again can you explain the Sammy Sanchez and Cadel Evans endorsements on your site. Are they endorsements? Do they know they are there?

If so what amount of their respective training schedules are spent on them?

 

[FrankDay]

Valid and reliable. Which means my claims can be replicated and tested.

Not if you won't give us the data.

There is no difference between this and any other Spam thread.

Except that this thread is now over 400 posts and some of them are actually on topic.