The Powermeter Thread

[veganrob]

Staying with the "practice" of the PM, what is the purpose of doing the measuring? Why do it? If runners (or almost any other athlete I can think of) don't need to measure power why do cyclists?

They use heart rate monitors. Again, a measuring tool. The PM is just a better way of measuring.

 

[JamesCun]

Staying with the "practice" of the PM, what is the purpose of doing the measuring? Why do it? If runners (or almost any other athlete I can think of) don't need to measure power why do cyclists?

I can guarantee that numerous people/groups are working on a 'power meter' for running.

Can you answer one question. What evidence do you have the a power meter will slow you down?

 

[JamesCun]

...Wait, according to Heisenberg and the Heisenberg Uncertainty Principle just measuring the power changes it, so I guess that is true (but is it changed up or down?), but not in the way that most think that it does.)...

Can you explain what quantum mechanics has to do with measuring power of a rider on a bicycle???

 

[FrankDay]

They use heart rate monitors.

Not all runners use HRM's and there is no scientific evidence using one results in faster runners.

Again, a measuring tool. The PM is just a better way of measuring.

Trying to stay with the science of PM's I think all one can say is a PM is a DIFFERENT way of measuring. Before one can say it is a BETTER way of measuring there has to be some evidence to support that of which there is none. To say it is better reflects your opinion only based on ...? Let's try to stay with the science and practice of PM's here if we can.

 

[FrankDay]

I can guarantee that numerous people/groups are working on a 'power meter' for running.

Good luck to them. LOL.

Can you answer one question. What evidence do you have the a power meter will slow you down?

The video that was posted awhile back? Theoretically, anything that distracts the rider from the task at hand has the potential to slowing them down. But, that is not the question as I see it, the question being does using a PM make the rider better than they could be without one? It it doesn't do that what good is it for the competitive cyclist?

 

[FrankDay]

Can you explain what quantum mechanics has to do with measuring power of a rider on a bicycle???

Well, staying with the "science of PM" theme, power requires knowing the speed of the bike. Knowing the speed requires knowing the position of the bike between two different times. According to Heisenberg, it is not possible to accurately know both the speed (momentum) and position of anything at the same time. This, affects the accuracy of the measured power. Even though the error is pretty small it is an accepted scientific fact. Just trying to stay with the science of PM theme. http://en.wikipedia.org/wiki/Uncertainty_principle

 

[JamesCun]

Good luck to them. LOL. The video that was posted awhile back? Theoretically, anything that distracts the rider from the task at hand has the potential to slowing them down. But, that is not the question as I see it, the question being does using a PM make the rider better than they could be without one? It it doesn't do that what good is it for the competitive cyclist?

Please stick to relevant arguments. A random video of something random happening that you have absolutely no knowledge of the specifics of the situation is about as weak an attempt as you could possible make.

So again I ask you a simple question, post some scientific evidence that a PM makes you slower.

 

[JamesCun]

Well, staying with the "science of PM" theme, power requires knowing the speed of the bike. Knowing the speed requires knowing the position of the bike between two different times. According to Heisenberg, it is not possible to accurately know both the speed (momentum) and position of anything at the same time. This, affects the accuracy of the measured power. Even though the error is pretty small it is an accepted scientific fact. Just trying to stay with the science of PM theme. http://en.wikipedia.org/wiki/Uncertainty_principle

I thought you were educated? Why twist quantum mechanics and the properties of waves and particles into a discussion of bicycles and power meters.

 

[FrankDay]

Please stick to relevant arguments. A random video of something random happening that you have absolutely no knowledge of the specifics of the situation is about as weak an attempt as you could possible make.

So again I ask you a simple question, post some scientific evidence that a PM makes you slower.

I am not aware of any scientific evidence that a PM does anything good or bad for the cyclist.

 

[JamesCun]

I am not aware of any scientific evidence that a PM does anything...bad for the cyclist.

See, that wasn't so hard. We didn't need quantum theories, or silly videos for that, did we. Glad we are on the same page now

 

[sittingbison]

Enough is enough. I don't know if you are deliberate or demented.

Closed while I try to get this discussion back on track. And pack your things Frank

 

[sittingbison]

I have purged a day of drivel, and issued a direct warning via PM.

Not happy Jan.

Keep to the topic. Be obtuse and derail and on your own head be it.

 

[coapman]

Riding your bike, diet, recovery, having goals, finding ways to learn to cycle better will help you improve as a cyclist.

A power meter is one way of measuring that improvement. The Garmin Vector is a good way of doing this. As are other models of power meters. There are some excellent reviews a few posts back.

http://www.brimbrothers.com/update-january-2015/

 

[sciguy]

http://www.brimbrothers.com/update-january-2015/

Noel,

Are you intending to purchase one of the early sets of these? I'm certain you'll learn a great deal by using them if you do and look forward to hear about your experience.

Hugh

 

[coapman]

Noel,

Are you intending to purchase one of the early sets of these? I'm certain you'll learn a great deal by using them if you do and look forward to hear about your experience.

Hugh

If it is a torque meter (around the circle) in addition to a power meter, the answer is yes as this will confirm what should have already been obvious to scientists that this man (when at max power output in the finishing straight on this track) is starting his power stroke around 11 and applying maximal torque at 12). https://www.youtube.com/watch?v=7hh2DcgpnkU

 

[Dear Wiggo]

If it is a torque meter (around the circle) in addition to a power meter, the answer is yes as this will confirm what should have already been obvious to scientists that this man (when at max power output in the finishing straight on this track) is starting his power stroke around 11 and applying maximal torque at 12). https://www.youtube.com/watch?v=7hh2DcgpnkU

I may have missed it and this may be OT, but did you ever do a diagram showing muscle force generation vs fixed hip, knee and ankle fulcrums vs the fixed BB and crank / pedal fulcrums to explain how maximum torque can be applied at 12 O'clock?

 

[Alex Simmons/RST]

If it is a torque meter (around the circle) in addition to a power meter,

You've been able to get such torque data at 200Hz from an SRM for decades. It just requires the torque analysis option.

 

[coapman]

You've been able to get such torque data at 200Hz from an SRM for decades. It just requires the torque analysis option.

That's true but as I have already explained, I am useless working on this equipment and need to have it set up for me and fully explained with the least possible inconvenience. DW I will answer your question in the PT thread.

 

[FrankDay]

You've been able to get such torque data at 200Hz from an SRM for decades. It just requires the torque analysis option.

What do you mean by "such data"? SRM strain gauges are downstream from the cranks so it combines the two cranks together so SRM cannot possibly provide individual pedal torque analysis. The SRM torque analysis option simply provides an output similar to Computrainer spinscan.

 

[Alex Simmons/RST]

What do you mean by "such data"? SRM strain gauges are downstream from the cranks so it combines the two cranks together so SRM cannot possibly provide individual pedal torque analysis. The SRM torque analysis option simply provides an output similar to Computrainer spinscan.

Coapman asked about data from a "torque meter around the circle". Providing the data on the net torque from both cranks is more than sufficient for this purpose.

 

[FrankDay]

Coapman asked about data from a "torque meter around the circle". Providing the data on the net torque from both cranks is more than sufficient for this purpose.

Here is what he wrote

If it is a torque meter (around the circle) in addition to a power meter, the answer is yes as this will confirm what should have already been obvious to scientists that this man (when at max power output in the finishing straight on this track) is starting his power stroke around 11 and applying maximal torque at 12).

Torque analyses that involve net torque (SpinScan, SRM) must make a certain assumption to do their analysis. The assumption they are forced to make is that NOTHING is done on the backstroke between 6 and 12. Having made this assumption they can then say what they see is what the rider is doing on the downstroke (and of course, "everyone" knows that is where all the power is generated so that is all that counts). The problem is, of course, that having made the assumption that NOTHING is done on the upstroke (between 6 and 12) that it is not possible to show that the rider is starting the power stroke at 11 since they assume he is not. Hence, I think it is quite clear that "Providing the data on the net torque from both cranks is" NOT "more than sufficient for this purpose." In fact, it is demonstrably useless for this purpose.

 

[Alex Simmons/RST]

Here is what he wroteTorque analyses that involve net torque (SpinScan, SRM) must make a certain assumption to do their analysis. The assumption they are forced to make is that NOTHING is done on the backstroke between 6 and 12. Having made this assumption they can then say what they see is what the rider is doing on the downstroke (and of course, "everyone" knows that is where all the power is generated so that is all that counts). The problem is, of course, that having made the assumption that NOTHING is done on the upstroke (between 6 and 12) that it is not possible to show that the rider is starting the power stroke at 11 since they assume he is not. Hence, I think it is quite clear that "Providing the data on the net torque from both cranks is" NOT "more than sufficient for this purpose." In fact, it is demonstrably useless for this purpose.

SRM makes no assumptions. They simply report net torque from both cranks. They make no claim about the independent torque applied to each crank, nor attempt to suggest their data can.

This net torque data is more than sufficient to answer Noel's questions. For sure having independent crank torque data can help further understand such things, but it isn't necessary for addressing what Noel has been banging on about for decades.

 

[Alex Simmons/RST]

By the way, pedal force data from a bicycle ridden on a track, and on the road up and down hills was first reported in the scientific literature in 1896. Yes, that's EIGHTeen ninety six.

Sharp, A. (1896). Bicycles and tricycles: an elementary treatise on their design and construction. Start from bottom of page 268.

It's funny to read their commentary on pedalling technique in section 215. At least we know the pedal technique myths tossed about on here are not original, and have been about for over 120 years.

 

[FrankDay]

SRM makes no assumptions. They simply report net torque from both cranks. They make no claim about the independent torque applied to each crank, nor attempt to suggest their data can.

This net torque data is more than sufficient to answer Noel's questions. For sure having independent crank torque data can help further understand such things, but it isn't necessary for addressing what Noel has been banging on about for decades.

It is impossible for the net torque data for two cranks together to mean anything about the individual crank torque (Noel's question) without making some assumptions. It is what SpinScan does. It is what SRM does otherwise it couldn't give you a left/right balance (and there is no guarantee even that is correct because of the assumptions made). The only thing that can be learned from such an analysis is how "smooth" the stroke is overall. Nothing is learned about the contribution of the two different cranks around their each individual circle that leads to that overall result.

 

[FrankDay]

By the way, pedal force data from a bicycle ridden on a track, and on the road up and down hills was first reported in the scientific literature in 1896. Yes, that's EIGHTeen ninety six.
...
It's funny to read their commentary on pedalling technique in section 215. At least we know the pedal technique myths tossed about on here are not original, and have been about for over 120 years.

I look forward to seeing your data, scientific evidence, to suggest that what they say in section 215 is, indeed, a myth. In fact, it is amazing that a better pedaling technique has been advocated since 1896 and the average cyclist still cannot do it just as described in 1896. Instead, because they cannot do it people use this continued use of a theoretically lesser technique as proof that what they do (the theoretically lesser technique) must be superior instead of considering this is simply evidence it is very difficult to learn and change. Believe whatever you must to keep on doing what you are doing.