wattbike help

Alex_Simmons/RST

liversedge wrote:

Well, I think the broader discussion is about pedalling, muscle recruitment, efficiency and performance. The SS numbers may or may not be accurate, I think that is a separate topic. I said "spinscan etc" to refer to all types of pedal analysis, since we we're discussing the wattbike, some of which I think will be coming with vector too?

I'm not precious on this, but you two seem very certain of your position and I personally don't feel you have explained why that is the case. But life is too short and the sun is shining

I can't say I'm precious either. What I will say is that when asked about the issues, I am guided by:
- the fundamental principles of physics and physiology
- the peer reviewed published research
- discussions with people/scientists who have actually studied the area extensively (in my case discussion with researchers at GIT who have lab force measurement pedals and have replicated much of what's already been found in the literature on the topic)

I am far less swayed by marketing claims.

This topic is not new of course. From a basic physics perspective, have a look at Chapter 11, Biomechanics by Koning and van Soest, in Asker Jeukendrup's excellent book, "High Performance Cycling".

Finally, if we are going to have a sensible discussion, then the use of precise terms to convey precise meaning is very important. Efficiency has a precise meaning in science. If we are going to toss that aside and all choose to think it means something else, then the discussion is pointless.

Alex_Simmons/RST

Pedal "technique" threads remind me of this great golf tip video:

http://www.pgatour.com/video/r/instruct ... index.html

bahzob

Alex_Simmons/RST wrote:

bahzob wrote:

Sorry Alex but you cannot just come up with a definition of efficiency then decide ipso facto that anyone who does not agree with this is wrong.

My apologies for referring to one of the most fundamental and accepted laws of nature when using the term efficiency.

http://en.wikipedia.org/wiki/Energy_con ... efficiency

Right. It was unclear from your previous replies that you understood this and I am afraid it still is.

This equation can apply to a system as a whole.

Or to its component parts. So again as a simple example. I have my car tested on a rolling road. This gives 2 figures. 100 BHP measured at the engine (Pin), 90 BHP (Pout) on the road. So 90% efficiency of the transmission. If I wanted to improve this then I could attempt various overall changes or look at the efficiency of the individual components. Further this 90% is only a small part of the total efficiency of the car itself which would include things like the ignition process and aerodynamics.

An similar situation applies to cycling. Metabolic power has to be converted to mechanical energy and an essential part of this is applying pressure to the pedals.

It is perfectly valid to isolate and talk about the "efficiency" of this process. So to return to the example of someone who pedals by pushing down hardest when the pedal is vertical.

You seem confused about this. You say if you are pushing down on something that does not move you are doing no work.

Wrong. Go back to your wiki entry. Pin will be high, the person pushing down on the pedal will certainly feel as if they are working very hard. Pout will be low though, because the process is so inefficient.

We both agree, ofc, that people do not really pedal this way.

However your assumption is that, looking just isolated portion of the total system that the way people apply pressure to pedals is either
- Pout = Pin making it an extremely rare, possibly unique case
- Pout < Pin by a significant amount but the factor is fixed absolutely for all riders so its not worth looking at
- Pout < Pin but the overall loss is negligible.

(I remind you that the "peer reviewed" evidence you have cited so far to support this view is flawed. )

I happen to think that
- Pout < Pin, this value can be significant, varies between riders and can be trained/improved.

My evidence is the riders in this video 5 mins in.

http://www.youtube.com/watch?v=VSdv7hRETe4

Your assumption is that the riders here are pedaling in the most efficient way possible. I find that very hard to believe. My view also explains why the riders here pedal in such a different way than accomplished cyclists. Yours would predict they should be the same.

Alex_Simmons/RST

So you are saying that the energy delivered the cranks (or rear tyre if you like) as a proportion of total energy metabolised is not consideration of the whole system?

I think you are confused about the difference between effectiveness and efficiency.

I had a look at the vid. Just a jerky helmet cam video of bunch of people riding bikes up an alpine pass. Not sure what that's got to do with measurement of efficiency or as evidence of what you are on about. In fact I'm actually sure what you are on about.

If a force does not act over a distance, then no work is done. That's just basic physics. W = F x d
See here for a reminder:
http://en.wikipedia.org/wiki/Work_%28physics%29

You say the science is flawed. In what way? Please provide some valid information to explain where Coyle et al, Korff et al, Martin et al, McDaniel et al etc all got it wrong.

bahzob

I think it's you who are confused.

How does "So you are saying that the energy delivered the cranks (or rear tyre if you like) as a proportion of total energy metabolised is not consideration of the whole system?" relate to the previous simple definition of efficiency that you cited and to the discussion on whether the way you pedal matters?

You also seem confused about work and efficiency. Efficiency is a measure of a ratio pure and simple. (see your link) You can apply it to a black box if you are capable of measuring the power in and the power out.

This ratio is handy if you have a number of black boxes, that you can interchange. Then you will be able to use the best one.

However if you only have one box you need to open it up and understand the reasons why it is inefficient. Then all manner of factors will reveal themselves including considerations of work.

Anyway don't get too hung up by this. I mentioned the example of someone trying to pedal by pressing down when the pedal was vertical as, I thought a clear, albeit trivial, example that the way you pedal has an impact on your performance. I take it you do accept that at least and would advise someone doing this to change the way they pedal?

Re the video. You also seem to be confused here. This thread is about pedaling. So look at the legs of the riders. You can tell a good cyclist from a bad one just by how they pedal, in the same way as you can spot a good runner from bad, good golfer from hack etc etc.

Your theory, as I understand it is:
- cyclists instinctively pedal in the best possible way
- this is an innate ability, it doesn't need to be learned and cannot be improved by training.
--- as corollaries
----> they can do this regardless of cycling situation
----> they can do this despite being innately unaware of factors related to bike setup which will cause their pedaling to be worse.

So it predicts that either
- all cyclists pedal the same way
- or you should see no difference in pedaling styles between groups of cyclists differentiated by performance.

Neither is the case. The video clearly shows this as does everyday experience.

Re the flawed science I covered this in a previous post. Do me the courtesy of reading it.

Edit PS. viewtopic.php?f=40011&t=12863156#p17708081 shows others seem to agree.

Alex_Simmons/RST

You are putting words in my mouth, so I'll leave it at that. I have suggested none of what you've written.

Anyway, congrats to one of my clients that (along with his team mates) won the British TTT championships this weekend. Must be the crap pedaling advise I give them to follow

As for the other post, argumentum ad populum still doesn't make something right.

bahzob

Alex_Simmons/RST wrote:

You are putting words in my mouth, so I'll leave it at that. I have suggested none of what you've written.

Anyway, congrats to one of my clients that (along with his team mates) won the British TTT championships this weekend. Must be the crap pedaling advise I give them to follow

As for the other post, argumentum ad populum still doesn't make something right.

Sorry I have had to put words into your mouth as you don't seem to be able of expressing yourself clearly on this matter.

The conclusion I take from your posts remains

You believe
- cyclists instinctively pedal in the best possible way
- this is an innate ability, it doesn't need to be learned and cannot be improved by training.
--- as corollaries
----> they can do this regardless of cycling situation
----> they can do this despite being innately unaware of factors related to bike setup which will cause their pedaling to be worse.

If this is wrong take this opportunity to state your theory clearly.

I also take it you accept the studies you cited earlier are flawed wrt to this subject and won't be using them again in future.

As for your final 2 sentences they do of course pretty close to a self contradiction. Congratulations to your cyclist, however a sample of one doesn't feel like much better evidence than that in the other thread.

ric/rstsport

<sigh>

liversedge

There is a handy review of the research here. You can register for free.

The review does show that conclusions about the relationship between pedalling biomechanics and gross efficicency are not as clear as some here would have you believe.

From the summary:

Further research is needed to test the effect of long-term changes in pedalling technique on gross efficiency

Alex_Simmons/RST

bahzob wrote:

Alex_Simmons/RST wrote:

You are putting words in my mouth, so I'll leave it at that. I have suggested none of what you've written.

Anyway, congrats to one of my clients that (along with his team mates) won the British TTT championships this weekend. Must be the crap pedaling advise I give them to follow

As for the other post, argumentum ad populum still doesn't make something right.

Sorry I have had to put words into your mouth as you don't seem to be able of expressing yourself clearly on this matter.

The conclusion I take from your posts remains

You believe
- cyclists instinctively pedal in the best possible way
- this is an innate ability, it doesn't need to be learned and cannot be improved by training.
--- as corollaries
----> they can do this regardless of cycling situation
----> they can do this despite being innately unaware of factors related to bike setup which will cause their pedaling to be worse.

If this is wrong take this opportunity to state your theory clearly.

I also take it you accept the studies you cited earlier are flawed wrt to this subject and won't be using them again in future.

As for your final 2 sentences they do of course pretty close to a self contradiction. Congratulations to your cyclist, however a sample of one doesn't feel like much better evidence than that in the other thread.

I am not going to respond to your strawman argument and false dilemmas. And assuming my lack of specific response to your fallacies as an acceptance of your assertions is a logical fallacy in itself (argumentum ex silentio).

You suggest the research is flawed, yet can't provide evidence of your own, apart from an amateur video of people riding up hills (which is not evidence in any way shape or form). Until you put those people on a metabolic cart in a lab and measure their power and gas exchange, you cannot say one way or another how efficient they are.

I've chosen to read and listen to people who have.

bahzob

Ric/RSTSport wrote:

<sigh>

/facepalm.

bahzob

"I am not going to respond to your strawman argument and false dilemmas. And assuming my lack of specific response to your fallacies as an acceptance of your assertions is a logical fallacy in itself (argumentum ex silentio)."

Sorry, all I am asking you to do is state clearly what your theory regards the role of pedaling is. Since you seem incapable of doing this I have been forced to take a guess at this based on your comments.

So again I ask you to state what your theory is. If you cannot do this you are by definition not in any position to dispute the views of others.

"You suggest the research is flawed, yet can't provide evidence of your own, apart from an amateur video of people riding up hills (which is not evidence in any way shape or form). Until you put those people on a metabolic cart in a lab and measure their power and gas exchange, you cannot say one way or another how efficient they are."

I have done more than suggest the research is flawed. I have pointed to specific issues with the protocol of the studies that renders them flawed wrt to this discussion.

Your repeated failure to respond to these means I have to assume you accept this but are not willing to admit you may be wrong. btw this isn't a logical fallacy. It's how science works.

Regards the video.The point is that I believe you can judge a riders ability simply by looking at how they are pedaling. Pedal better = Perform better. These cyclists are evidence of this point.

I remain of the view that their performance would improve if they spent time improving their pedaling skill and, getting back to the original topic, the display on the Wattbike could help with that.

bahzob

liversedge wrote:

There is a handy review of the research here. You can register for free.

The review does show that conclusions about the relationship between pedalling biomechanics and gross efficicency are not as clear as some here would have you believe.

From the summary:

Further research is needed to test the effect of long-term changes in pedalling technique on gross efficiency

Thanks for this link.

bahzob

Another view on this topic.

http://pezcyclingnews.com/?id=8076&pg=fullstory

Its relevant to this topic because:
- It provides a diagram summarising the muscles involved and how their contribution is affected by the crank angle in the pedal stroke. It's not simple, that's why, I'd suggest, as with all other comparable skills some individuals are naturally good at pedaling and others not. It would be very surprising I would think if everyone was equally gifted.

- The roles efficiency/effectiveness are explained. I think this may help explain some of the confusion earlier.

- The Korff study is referred to however a different interpretation follows. (Though as aalready mentioned I am not convinced the protocol used makes this a very good study.).

- It notes another study showing cyclists may well have an innate pedaling rhythm but this does not cover whether this is adapted through training.

- The summary is pretty much in accord with my view, but not I suspect those of Alex.

"Every cyclist pedals a little differently than their peers. While the motor recruitment patterns of the primary movers can be isolated and used to teach the athlete the central tenants of the pedal stroke, it is important to realize that one approach to pedaling efficiency doesn’t work for everyone.

Indeed, Korff et all demonstrated that the while the overall effectiveness of the ‘pull up” technique is much greater than is shown by pedaling circles or stomping, the overall efficiency of that technique is lower. The question remains whether the increased effectiveness is worth the trade off in efficiency.

Similarly, Hansen and Ohnstad were able to establish that during sub-maximal efforts each individual has an innate voluntary motor rhythm that plays a significant role in cadence despite the introduction of internal and external variables intended to alter performance. While we all may have an internal rhythm I think the question remains whether or not this is amenable to training effects or not.

The practical application of this information is to become a student of your stroke. Take the information above and go apply it in your own real-world experiments and technique drills. There can be no doubt that having an arsenal of pedaling skills and knowledge will serve to ultimately help you arrive at your own best pedaling practices".

P_Tucker

What a f*cking useless study. Here's a graph, and a load of useful questions this study makes no attempt to answer, and one utterly pointless question that is has answered.

If you're going to prove Alex and Ric wrong you'll need to try harder FFS

Alex_Simmons/RST

bahzob wrote:

Another view on this topic.

Perhaps you are confusing someone's opinions on some research as the science itself?

Nevertheless, Matt's a good guy and I don't see much wrong with what's he's said. I don't disagree with going and doing some pedaling drills (but ones that make sense, not some of the nonsense we sometimes see posted up), have said so before, as well as umpteen times suggested good bike fit is fundamental to such things. He's interviewed me (and Ric) on matters pertaining to cycling performance before for articles on Pez.

bahzob

No don't think I am confused about the Pez article. You have your opinions on the research, I am just showing others also do and come to different conclusions.

I remain very confused about your views though. Very seriously I don't understand your position wrt to the role of pedaling skill.

Are you saying it doesn't exist or has no contribution to make? That is the clear impression I have received so far. I can't recall anything you have posted here making a positive suggestion on its role, only criticism a la this latest post.

Yet here you say you don't disagree with going out and doing pedaling drills? (so long as they are not "nonsense" ofc so it may help if you could say what you would recommend.)

Nor do you contradict the statements in Matt's article.

"Every cyclist pedals a little differently than their peers. While the motor recruitment patterns of the primary movers can be isolated and used to teach the athlete the central tenants of the pedal stroke, it is important to realize that one approach to pedaling efficiency doesn’t work for everyone."

"The practical application of this information is to become a student of your stroke. Take the information above and go apply it in your own real-world experiments and technique drills. There can be no doubt that having an arsenal of pedaling skills and knowledge will serve to ultimately help you arrive at your own best pedaling practices".

Which is pretty much what I have been saying all along.

P_Tucker

That is the worst summary of anything, ever. Basically, it follows this format:

Here's a load of inconclusive science and a nice diagram... SOOOOOO... in summary you should do this stuff which coincidentally was what I'd have said before I'd looked at the science.

FFS

Herbsman

bahzob - have you tried religion? It might suit you better.

bahzob

Hm I guess you guys didn't read Alex's view that the article was a good one and he didn't see much wrong with it.

And the "inconclusive science" Tucker finds so offensive is the science Alex is using to support is opinion. Go figure.

Still you obviously rate your knowledge on this subject. Perhaps you can try answering the questions which I asked in the last post to Alex?

bahzob

Interesting to look at the ITV4 coverage of today's stage of the tour in the light of this topic. (and congrats to Chris Froome and Brad btw)

1. Todays stage: Paul Sherwen's comments at around 53,7 km to go and in the last 4 km, observing
- the difficulty that even top riders have adjusting their pedaling styles from fast and flat to tough and steep. Not exactly consistent with a theory that riders don't need to worry about how they pedal?
- the smoothness of the riders action even under max stress. (One measure of the degree of any skill is how well it stays consistent (and ofc "efficient") under pressure.) Top riders retain good form much closer to breaking point than average riders.

2. Its easy to spot the difference between just "ok" cyclists and good cyclists. Just observe the difference between how "Francis" in the Halford's adverts pedals and the way the pros do it. And Francis is an ok cyclist, most don't look anywhere near as good especially when under the sort of pressure shown today on the last 6 km.

Getting back to the original topic, if both Francis and one of the tour riders were on Wattbikes then the difference would be evident on the polar display. Using it Francis could, hopefully, learn to pedal a bit more like the pros and both look better and cycle better as a result.

Herbsman

Paul Sherwen is a commentator, not a sports scientist you mug. His comments are not evidence of anything

liversedge

Herbsman wrote:

Paul Sherwen is a commentator, not a sports scientist you mug. His comments are not evidence of anything

That's harsh. He is also an ex "professional bike racer" (as he would say). He certainly knows a thing or two about riding a bike, albeit not biomechanics.

t.m.h.n.e.t

Bahzob's getting a tad desperate now.

P_Tucker

bahzob wrote:

Interesting to look at the ITV4 coverage of today's stage of the tour in the light of this topic. (and congrats to Chris Froome and Brad btw)

1. Todays stage: Paul Sherwen's comments at around 53,7 km to go and in the last 4 km, observing
- the difficulty that even top riders have adjusting their pedaling styles from fast and flat to tough and steep. Not exactly consistent with a theory that riders don't need to worry about how they pedal?
- the smoothness of the riders action even under max stress. (One measure of the degree of any skill is how well it stays consistent (and ofc "efficient") under pressure.) Top riders retain good form much closer to breaking point than average riders.

2. Its easy to spot the difference between just "ok" cyclists and good cyclists. Just observe the difference between how "Francis" in the Halford's adverts pedals and the way the pros do it. And Francis is an ok cyclist, most don't look anywhere near as good especially when under the sort of pressure shown today on the last 6 km.

Getting back to the original topic, if both Francis and one of the tour riders were on Wattbikes then the difference would be evident on the polar display. Using it Francis could, hopefully, learn to pedal a bit more like the pros and both look better and cycle better as a result.

So, you are attempting to argue against scientific consensus by citing a cycling commentator and a Halfords advert?

bahzob

"So, you are attempting to argue against scientific consensus by citing a cycling commentator and a Halfords advert? "

I think you are confused and a tad insulting.

Insulting, not to me (not that I care tbh). To Paul Sherwen. Look up his cv.

Confused. Well if you are not state clearly what exactly does the "scientific consensus" show?

So far, based on his input, I took Alex's views to be:

- cyclists instinctively pedal in the best possible way
- this is an innate ability, it doesn't need to be learned and cannot be improved by training.
--- as corollaries
----> they can do this regardless of cycling situation
----> they can do this despite being innately unaware of factors related to bike setup which will cause their pedaling to be worse.

IOW you are as good at pedaling as Bradley Wiggins.

I take it you agree with these statements? If no what do you believe?

Whatever reference the specific studies that support them. (Alex's are flawed so don't just parrot them.)

Also please give your explanation of the fact that no cyclists in the tour de france have a bad pedaling action while most cyclists in sportives do.

Alex_Simmons/RST

Stop misrepresenting me with ridiculous strawman arguments. It's rather tedious.

liversedge

It is plain that there are some very fixed views here and a thread on bikeradar isn't going to change them. I suggest this thread is left to die with a modicum of dignity!

P_Tucker

liversedge wrote:

It is plain that there are some very fixed views here and a thread on bikeradar isn't going to change them. I suggest this thread is left to die with a modicum of dignity!

NEVER

bahzob

Alex_Simmons/RST wrote:

Stop misrepresenting me with ridiculous strawman arguments. It's rather tedious.

What's tedious Alex is you not actually saying what your position is while being very quick when it comes to picking holes in others.

So stop complaining about being misrepresented and say what you actually believe and how this is consistent with your other posts here.