The importance of crank length to the cyclist.

[CoachFergie]

He may well have looked at both. Speed, in competition, can be a useful metric. Especially if you have time checks to compare with. That being said you don't want to blow up on the first hill (if there are any).

Look at speed in a time trial? On a lap like that with cobbles and other technical sections. You would have needed to be looking at a speed reading way more than an average power. What fool said that? Love it when people criticise something they don't understand.

 

[Martin318is]

Yes it is big assumption, as that PM help us beeing faster (although beeing smarter or race prediction are wright words).
Even if he checking numbers periodically, what numbers he checked? Did he ride before that course? He did not.
Did he nows that he must hit 500 or so average watts? Maybe
Did he knows wind speed and then calculate his avg? I doubt
Too many corners, too many variables IMHO.

Did he maybe look at speed instead watts, we will never know I heard that dude who hit 50km/h avg or more would be medalist, not that one who hit 500 watts avg!!!
Do not get me wrong, PM are great tool, not like that SRM dude present us "How do I sell Power" slide. But What might happens if Wiggins did not look at damn thing at all, maybe he would be World Champion.

Well done, that is the whole thing in a nutshell. If Tony Martin knew through recent training and testing that the best he could maintain for an X minute time trial effort was 35Watts then all he had to do to get his best possible time over X distance was ensure that he was holding his best aero position and doing that 35W number or better. Whatever 'speed' someone else coud do is irrrelevant. If his best is good enough to hit that average speed then yes, he would win. How does he ensure he is doing his best without risking cracking early? By monitoring his average power output. all other factors such as short inclines, corners, weather etc become effectively irrelevant because if he focuses upon doing his best combination of power/weight/aero then he will effectively do the best he can in the circumstances

 

[CoachFergie]

I would suggest for that course aiming a little lower for average power reflecting the tight turns and getting to halfway and assessing whether to pick it up. The chart I linked showed Wiggins did this rather well. We know the result but power can tell us who had the better performance. If Wiggins set a PB by 10 watts and Martin by only 5 watts then Wiggins had the better performance. Martin won because on the day he was the better rider.

And just to stay on topic, all the top riders were on long cranks

 

[oldborn]

Well done, that is the whole thing in a nutshell. If Tony Martin knew through recent training and testing that the best he could maintain for an X minute time trial effort was 35Watts then all he had to do to get his best possible time over X distance was ensure that he was holding his best aero position and doing that 35W number or better. Whatever 'speed' someone else coud do is irrrelevant. If his best is good enough to hit that average speed then yes, he would win. How does he ensure he is doing his best without risking cracking early? By monitoring his average power output. all other factors such as short inclines, corners, weather etc become effectively irrelevant because if he focuses upon doing his best combination of power/weight/aero then he will effectively do the best he can in the circumstances

Martin agree with you at some points. But even I realized that 51km/h would won that TT.
Maybe Martin was self paced based on PE.
If Martin had (and he had testings) those testings were not on that same course and under same conditions (look at those "sleeping policeman", or cobles) so IMHO he could not rely 100% on watts, Dude maybe just know how to pace himself well.
I am saying that speed is also influenced by those factors, but maybe speed not watts he really looks.

 

[oldborn]

He may well have looked at both. Speed, in competition, can be a useful metric. Especially if you have time checks to compare with. That being said you don't want to blow up on the first hill (if there are any).

Good point mate.
I am sure that Martin (and others) crew behind him talk to him on radio like this:" Come on dude, you are shaving x riders by 25 seconds, keep that speed of 50km/h, you are doing great, whole Germany is with you"

Rather than this: "Come on dude, you are doing 450 watts superb, I will not tell you about others watts, cos I do not have a damn clue about it"

 

[Tapeworm]

Look at speed in a time trial? On a lap like that with cobbles and other technical sections. You would have needed to be looking at a speed reading way more than an average power. What fool said that? Love it when people criticise something they don't understand.

Who's being critical?

 

[Boeing]

Yup 368 posts and no evidence about the "importance" of crank length has been forthcoming. This thread is the cyclingnews forum equivalent of "Seinfeld".

and if we read your posts, there is no evidence it isn't important. which is the point


btw, why do kiwis have vasectomies? be cause they like to feel impOtent.

 

[Martin318is]

Martin agree with you at some points. But even I realized that 51km/h would won that TT.

wel yeah, 54km would have won the TT too. Here is teh problem. Its not a linear course with no variation, there are gradients, surface changes and wind angle of attack changes.

So does that mean that you would go onto the course and SIT on 51km regardless of any of those variables? Or would you start out as fast as possible and deall with the fatigue later, or would you start out slow and build, or something else?

THe only reliable way of doing YOUR best effort (note that this is different to winning the race because hey, maybe you arent good enough to actually win) is to maximise the interaction of power<>weight<>drag<>duration. Given that you know your body and bike weight, know your drag from wind tunnel testing, know the duration of the event, the only other thing you need to know is what power to put out to maximise that. And then you just need to make sure you are doing it.

If the most you can do for a 40km TT is say 300W then what speed you are doing is irrelevant. In the tail wind sections you do 300W, in the headwinds you do 300W on the uphill 300W on the down 300W. Other than this, you may decide - as Wig did - to drop it to 295 so you can try to do 320 in the final. Whatever. The point is that what speed you are doing is immaterial. (right up to the moment that you have to compare it to the finish times of others.) You couldnt have done it faster because of the afforementioned limitations

as is often said, HR and PE can be environmentally, emotionally, or mentally affected, but 300W is 300W.

 

[blutto]

wel yeah, 54km would have won the TT too. Here is teh problem. Its not a linear course with no variation, there are gradients, surface changes and wind angle of attack changes.

So does that mean that you would go onto the course and SIT on 51km regardless of any of those variables? Or would you start out as fast as possible and deall with the fatigue later, or would you start out slow and build, or something else?

THe only reliable way of doing YOUR best effort (note that this is different to winning the race because hey, maybe you arent good enough to actually win) is to maximise the interaction of power<>weight<>drag<>duration. Given that you know your body and bike weight, know your drag from wind tunnel testing, know the duration of the event, the only other thing you need to know is what power to put out to maximise that. And then you just need to make sure you are doing it.

If the most you can do for a 40km TT is say 300W then what speed you are doing is irrelevant. In the tail wind sections you do 300W, in the headwinds you do 300W on the uphill 300W on the down 300W. Other than this, you may decide - as Wig did - to drop it to 295 so you can try to do 320 in the final. Whatever. The point is that what speed you are doing is immaterial. (right up to the moment that you have to compare it to the finish times of others.) You couldnt have done it faster because of the afforementioned limitations

as is often said, HR and PE can be environmentally, emotionally, or mentally affected, but 300W is 300W.

....once you think about this for a few moments this idea of racing around a course with your eyes glued to a power meter is really not all bad....in fact it has some very interesting possibilities in this brave new world of video gaming and digital modelling....

...what we could do, to save time and effort for race organizers, is have the various riders submit power outputs and then have those outputs applied to a digital simulation of the ( or a standardized ) course...hit a start button and a computer would spit out a winner...and would be a true win-win situation, we would have an event with a saleable conclusion and with none of the bother ( and costs ) of actually staging the event in the real world...



Cheers



blutto

 

[Alex Simmons/RST]

Perhaps you should have given the presentation then. But improvement happens or doesn't whether it is measured or not.

If performance hasn't been measured, how do we know if an improvement has (or has not) actually happened?

Sounds like a philosopher's conundrum

But that change can be multi-direction and that viewing behaviour could work against you. Being a slave to the numbers could mean you miss technical aspects of your preparation (Cancellara) and if you do all your training by numbers for an IP and struggle without the power number in front of you.

Of course, I wasn't suggesting the impact on human behaviour of measurement was necessarily always positive.

I have a slide or two about power meters and psychology.

And of course power may not be the factor holding back a rider's performance. At least with a power meter one can quickly determine if that's actually the case and make sound decisions about the balance of training focus (tactical, skill, physiological, psychological etc).

I don't think Cancellara lacked technical prep, I just think he realised he was down and decided to take additional risks as a means to gain time. It was a gamble that did not pay off.

Schleck's TT in the 2011 TdF did lack technical preparation.

 

[Alex Simmons/RST]

It must be particularly distressing for the GM advocates that the only study to look at the question found no benefit. Or, maybe, not since the study hasn't changed a single opinion as far as I can tell.

It sure isn't distressing me.

What concerns me is when a measurement device doesn't measure properly.

What one does or can do with the information is something else entirely.

 

[FrankDay]

Didn't LeMond say the same about Gimmickcranks? Perhaps he confused them with Power Measuring Cranks or did you get a signed World Champions Jersery as well Frank

Actually, what Lemond said to me after his first ride on a PowerCranks bike was "I spent years trying to learn how to pedal this way, now people can learn it in months."

 

[FrankDay]

Well done, that is the whole thing in a nutshell. If Tony Martin knew through recent training and testing that the best he could maintain for an X minute time trial effort was 35Watts then all he had to do to get his best possible time over X distance was ensure that he was holding his best aero position and doing that 35W number or better. Whatever 'speed' someone else coud do is irrrelevant. If his best is good enough to hit that average speed then yes, he would win. How does he ensure he is doing his best without risking cracking early? By monitoring his average power output. all other factors such as short inclines, corners, weather etc become effectively irrelevant because if he focuses upon doing his best combination of power/weight/aero then he will effectively do the best he can in the circumstances

But, that is hog-wash. gimmick meters simply monitor effort, power is the way they measure effort. Other measures of effort are HR and perceived exertion. So, it is possible to measure effort for pacing with using a gimmick meter.

But, the gimmick meter is more accurate, many claim. But, does that increased accuracy make a difference? At some point, increasing accuracy will have little effect on outcome. Does a GM that can measure power to 0.01 watts more valuable than one that can only measure to 1 watt. One is 100 times more accurate than the other but does that accuracy give better results? I don't know but my guess is no.

So, the question is, does the increased accuracy of the GM give the athlete an advantage over the other methods? It might but it has never been shown.

Further, some would claim that it isn't the gm itself but how it is used. Doesn't help if it isn't used right. Well, if you are going to make that claim then you need to have some data that suggests what the correct way is and that using the gm that way makes a difference. It may be true, but there is zero scientific support to the claim.

 

[FrankDay]

What one does or can do with the information is something else entirely.

Well, where is the data that using the data in a certain way is the important thing to making the gm worthwhile? How the data is used probably is important if there is a benefit. But, no one is telling us how that way is nor can they provide any scientific evidence to support the contention.

 

[oldborn]

wel yeah, 54km would have won the TT too. Here is teh problem. Its not a linear course with no variation, there are gradients, surface changes and wind angle of attack changes.

So does that mean that you would go onto the course and SIT on 51km regardless of any of those variables? Or would you start out as fast as possible and deall with the fatigue later, or would you start out slow and build, or something else?

THe only reliable way of doing YOUR best effort (note that this is different to winning the race because hey, maybe you arent good enough to actually win) is to maximise the interaction of power<>weight<>drag<>duration. Given that you know your body and bike weight, know your drag from wind tunnel testing, know the duration of the event, the only other thing you need to know is what power to put out to maximise that. And then you just need to make sure you are doing it.

If the most you can do for a 40km TT is say 300W then what speed you are doing is irrelevant. In the tail wind sections you do 300W, in the headwinds you do 300W on the uphill 300W on the down 300W. Other than this, you may decide - as Wig did - to drop it to 295 so you can try to do 320 in the final. Whatever. The point is that what speed you are doing is immaterial. (right up to the moment that you have to compare it to the finish times of others.) You couldnt have done it faster because of the afforementioned limitations

as is often said, HR and PE can be environmentally, emotionally, or mentally affected, but 300W is 300W.

Martin agree with you at some points, but.
Let see how my plan is to shave 5 minutes on 90km bike leg (2h53min) 1/2 IM distance, this year avg speed 31,4km/h, next year plan is 32,4km/h (2h48min), with 900m elevation gain.

Just 10 points:
1.Removing 1,5cm spacers (getting more aero)
2.Moving ISM saddle 0,5 cm forward
3.Shorter cranks 172 or shorter (i am riding 175 from old 58 bike)
4.60mm deep rims
5.Going little bit harder on hills
6.Eating and drinking while on small descents
7.Aero helmet
8.Stay aero on 1-3% ascents and going more harder
9.Remove bottles from down/seat tube
10.Adjust elbow pads (getting more aero) and stay in triathlon suit after swimm whatever cold it would be.
11.Quit smoking LOL

With all this mine power would drop and I should be faster, how is that possible?

I just can not see where PM would fit there. All those possible improvements should cost me around 400-450 euros
How much it would cost to buy PM and I can not be sure that I am going faster with it.

I am just saying.

 

[FrankDay]

that is a big assumption on your part though. the screen wasn't covered and whilst it was difficult to see it at any particular time, there is nothing stopping him from periodically checking the main figure by glancing between his arms. review the tape of the TT and you will see him doing this. you will also see him glancing down as he props up on the drops to enter corners. Riding with a PM isnt about obsessively monitoring your power ever 3 to 5 seconds. It is about making sure that you are holding the % of your maximum that is applicable for a set period. This can be done by setting the screen to show average power and checking periodically that it is not fluctuating greatly.

One of the more constant "advantages" for the GM thrown out by the advocates is that HRM has a substantial delay in reflecting effort whereas the PM tells the rider what he is doing now. Then, you come and tell us that the best way to use it is to make the display show an average power. Now, average power gives one the average for the entire ride, not the last 3-10 seconds. Therefore, such a readout would be even less reflective of current effort than HR would be. So, where does the benefit come from again? What is the proper use for best benefit?

 

[FrankDay]

Martin agree with you at some points, but.
Let see how my plan is to shave 5 minutes on 90km bike leg (2h53min) 1/2 IM distance, this year avg speed 31,4km/h, next year plan is 32,4km/h (2h48min), with 900m elevation gain.

Just 10 points:
1.Removing 1,5cm spacers (getting more aero)
2.Moving ISM saddle 0,5 cm forward
3.Shorter cranks 172 or shorter (i am riding 175 from old 58 bike)
4.60mm deep rims
5.Going little bit harder on hills
6.Eating and drinking while on small descents
7.Aero helmet
8.Stay aero on 1-3% ascents and going more harder
9.Remove bottles from down/seat tube
10.Adjust elbow pads (getting more aero) and stay in triathlon suit after swimm whatever cold it would be.
11.Quit smoking LOL

With all this mine power would drop and I should be faster, how is that possible?

I just can not see where PM would fit there. All those possible improvements should cost me around 400-450 euros
How much it would cost to buy PM and I can not be sure that I am going faster with it.

I am just saying.

I thought having a bottle on the seat tube improved aerodynamics over not having one. Not intuitive but I thought that was what the data showed. Puts the rear wheel in the wind shadow of the bottle I guess.

 

[Alex Simmons/RST]

With all this mine power would drop and I should be faster, how is that possible?

I just can not see where PM would fit there.

That just shows your lack of understanding (or ignorance) of how a power meter enables you to make smart decisions about which of those changes result in improvements to speed and which do not.

A power meter enables one to not only measure power, but also your aerodynamics and rolling resistance.

Pithy Power Proverb:
"Increase the power one can produce, reduce the power one must produce" - J. Martin

 

[Alex Simmons/RST]

I thought having a bottle on the seat tube improved aerodynamics over not having one. Not intuitive but I thought that was what the data showed. Puts the rear wheel in the wind shadow of the bottle I guess.

Well if you have a power meter, you can prove this for your bike and set up one way or the other.

There are many "aero myths" that a power meter can bust.

 

[oldborn]

I thought having a bottle on the seat tube improved aerodynamics over not having one. Not intuitive but I thought that was what the data showed. Puts the rear wheel in the wind shadow of the bottle I guess.

Ok then, will leave damn bottle on the seat tube

 

[oldborn]

That just shows your lack of understanding (or ignorance) of how a power meter enables you to make smart decisions about which of those changes result in improvements to speed and which do not.

A power meter enables one to not only measure power, but also your aerodynamics and rolling resistance.

Pithy Power Proverb:
"Increase the power one can produce, reduce the power one must produce" - J. Martin

I will use common sense and well known findings to help me Alex, common sense
Smart decisions are not allways expensive one

If only one of those improvements (even I do not have a clue which one) help me to shave time, that is one more reason to not buy PM

P.S. Will let you know next year, wheather I was wright or not.

 

[CoachFergie]

But, that is hog-wash. gimmick meters simply monitor effort, power is the way they measure effort. Other measures of effort are HR and perceived exertion. So, it is possible to measure effort for pacing with using a gimmick meter.

Power meters measure work performed. HR and RPE are affected by other factors beyond power delivered to the pedal.

But, the gimmick meter is more accurate, many claim. But, does that increased accuracy make a difference? At some point, increasing accuracy will have little effect on outcome. Does a GM that can measure power to 0.01 watts more valuable than one that can only measure to 1 watt. One is 100 times more accurate than the other but does that accuracy give better results? I don't know but my guess is no.

Your biased "guess" has been duly noted. A bias that is based on power meters being the simplest way to disprove your many claims.

So, the question is, does the increased accuracy of the GM give the athlete an advantage over the other methods? It might but it has never been shown.

What other way could any athlete know they have really improved. I'm sure that Martin is stoked to win his first World Title, Wiggins to get on the podium in the event for the first time and Cancellara will be wondering where it all went wrong this season. With Olympics next year I wonder what metric they will be chasing to get it right in London.

Further, some would claim that it isn't the gm itself but how it is used. Doesn't help if it isn't used right. Well, if you are going to make that claim then you need to have some data that suggests what the correct way is and that using the gm that way makes a difference. It may be true, but there is zero scientific support to the claim.

Still confusing measuring power with strategies to increase power. Sure seems like nearly every rider at Worlds was measuring their performance in the TT with a power meter. I would expect none were using that information to increase performance. They will use the information to guide training, steer aerodynamic, positional changes and make equipment choices.

What there is zero scientific for is a change in crank length increasing the power one can deliver or decrease the wattage demands at a given speed. Looking at the fields from worlds it would appear that claims of compromised aerodynamics running long cranks is just a myth.

 

[oldborn]

....once you think about this for a few moments this idea of racing around a course with your eyes glued to a power meter is really not all bad....in fact it has some very interesting possibilities in this brave new world of video gaming and digital modelling....

...what we could do, to save time and effort for race organizers, is have the various riders submit power outputs and then have those outputs applied to a digital simulation of the ( or a standardized ) course...hit a start button and a computer would spit out a winner...and would be a true win-win situation, we would have an event with a saleable conclusion and with none of the bother ( and costs ) of actually staging the event in the real world...

Cheers
blutto

Or this one: In team bus before hill stage start

Coach: Ok guys today is the moment of truth, today we will hit some serius watts. At first climb John and Mark will try to escape and hit 450 watts for 10minutes, and 560 watts for 5 minutes, while Andrew will just sit and wait behind our main oponent Jose.

John: Coach what will happens if I hit 440 watts and still be in main bunch?

Coach: Do not ask me why but you should hit those numbers even you may be near death.

John: Ok boss

Coach. Then guys final climb is where Andrew will hit 560 watts, you hear me well 560 watts. All the way down to to top, no mather what happens.

Andrew: Boss, how should I know that I am prepare for this kind? Should I hit 557 watts, I mean I hate to look at numbers.

Coach: Andrew are you stupid or what. Watts does not lie, you can hit those numbers remember.

Happy to have no such races and coaches yet

 

[Alex Simmons/RST]

I will use common sense and well known findings to help me Alex, common sense
Smart decisions are not allways expensive one

Who said I was advocating expensive decisions?

Indeed I am advocating the smart use of a measurement tool so that one can make very effective but quite cheap improvements.

You are talking about changing wheels, helmet & cranks without actually knowing how much improvement they represent for your investment.

If only one of those improvements (even I do not have a clue which one) help me to shave time, that is one more reason to not buy PM

P.S. Will let you know next year, wheather I was wright or not.

But what if some of those changes actually reduces your speed?

And can you distinguish between improvement due to being fitter, due to improved aerodynamics, and/or better weather conditions?


OK, well, going over your list:

Just 10 points:
1.Removing 1,5cm spacers (getting more aero)
This may or may not improve your aerodynamics and may reduce your power output. Lower is not always better, depends on current positionw Until you test to determine whether or not your power to aero drag ratio increases, then you won't know if this is better for you.

2.Moving ISM saddle 0,5 cm forward
See #1

3.Shorter cranks 172 or shorter (i am riding 175 from old 58 bike)
See #1

4.60mm deep rims
Depends on what you are using now. Why not use something even faster if you are spending the money? A rear wheel cover is excellent aero bang for you buck. Don't forget good tyres and latex tubes.

5.Going little bit harder on hills
Harder than what? Perhaps you are already going hard enough and going harder may in fact be sub-optimal. I have examined pacing of many long course triathletes and one of the most common mistakes is going too hard on the hills.

6.Eating and drinking while on small descents
Not sure where on the course you choose to eat will impact your overall speed?

7.Aero helmet
Most likely, if your current helmet is not all that aero. However not all aero helmets are the same on all riders (I have tested one aero helmet that was no better than my mass start helmet). What is aero on one rider is not necessarily nearly as aero on another rider. This is especially an item that riders really should test for themselves. Do not rely on what works for someone else.

8.Stay aero on 1-3% ascents and going more harder
You mean you weren't staying aero before on shallow gradients?
Then yes this will probably help, although when you go to 2%+ gradient, power to weight plays a much bigger role (at 2% gradient the power to overcome air resistance and gravity is roughly equal), so if you are sacrificing power in your aero position, then you will need to know how to modify that position on such gradients for best overall impact to speed.

9.Remove bottles from down/seat tube
As Frank points out, that may or may not help.

10.Adjust elbow pads (getting more aero).
In what way? How will you know if the change is better? e.g. on some riders, narrow elbow pads is faster, for others a wider pad position is faster. Everyone is different. That's why we test to make sure.

10.and stay in triathlon suit after swimm whatever cold it would be.
No comment. Clothing is one significant area of aero improvement opportunity. Do not allow anything that flaps in the wind.

11.Quit smoking LOL

This one will save you money!!

 

[FrankDay]

You are talking about changing wheels, helmet & cranks without actually knowing how much improvement they represent for your investment.

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? All the device can do for sure is measure one important aspect of cycling performance but there is no evidence it helps the cyclist attain that improvement.