How would you Design a pedal Stroke Analyzer?

I'd start by figuring out what makes the best pedal stroke.

rschlend said:

Hi--

I'm an engineer and an recreational cyclist. I spend plenty of time on a trainer. I've looked at Racermate's Pedal Stroke Analyzer and always thought it would be a useful thing to have. I'm not willing to shell out the ~$1200 for it however.

I realized I could build something which would simply attach to the rear wheel of a bike on any trainer and provide the same information via a little screen attached to my handle bars. I'm estimating it would cost around ~$250. Would anyone else be interested in something like this?

Thanks!

Rob

force measuring pedals...

ric

So, essentially you'll want t display where in a 360' pedal stroke is the power being developed.

A bar mounted device like this would be useful and something I'd buy. I find the Computrainer SpinScan very useful.

A device like this would be great for working on optimising traction on MTB.

I'd have thought the shortest route would be to pick up the data from Ergomo/SRM/Powertap and just display it differently, rather than design another device.

You'd then just need to produce a 'Y' cable appropriate for the device. You'd also have a ready market out there from all of the Power users.

Or better still, reverse engineer the Ergomo/SRM/Powertap computers and make a '1 device fits all' unit with additional function like SpinScan, GPS and all the other things we'd all like in one unit.

rschlend said:

Hi--

I've looked at Racermate's Pedal Stroke Analyzer and always thought it would be a useful thing to have.

Why do you think it would be useful?

beerco said:

Why do you think it would be useful?

For the same reason Spin Scan is useful on a Computrainer.

mindracing said:

For the same reason Spin Scan is useful on a Computrainer.

So what objective evidence is there that the SpinScan function is useful?

I have Spinscan on my Velotron and have no plans to ever use it because I don't believe it works and that even if it did, it would not be useful.

I also never use the 3D videogame mode. I ride in ergometer mode all the time.

acoggan said:

So what objective evidence is there that the SpinScan function is useful?

For road riding and power development probably none.

However, it's certainly improved my MTB traction.

beerco said:

Why do you think it would be useful?

From my understanding there are more and less efficient ways to pedal. I'd prefer to apply the same amount of force with each leg for example. Additionally, the theory goes that applying a force throughout the pedal stroke[font=&quot] [/font]recruits more muscle groups creating better endurance, economy and balance of strength.

I live in the middle of a city and with work and life, end up cycling on a trainer at night frequently. It seems like a good time to work on pedaling efficiency. A tool that would verify I was using equal amounts of force on each leg and a method for reducing my dead-spots seems pretty useful.

Here are a few links to some articles I've read on pedaling:

http://www.roadcycling.com/training/pedalingtechnique.shtml
http://www.53x12.com/do/show?page=article&id=43
http://www.pezcyclingnews.com/?pg=fullstory&id=850

Thanks for the question!

Rob

rschlend said:

From my understanding there are more and less efficient ways to pedal.

Your understanding is incorrect.

mindracing said:

For road riding and power development probably none.

However, it's certainly improved my MTB traction.

Still able to get traction using snake oil?

Wouldn't the best way to pedal be the way that develops the most power? I think there's already something that measures that.

acoggan said:

Your understanding is incorrect.

Can you explain a bit, please, Andy. I'm not challenging your answer -- I just really want to know why you say this.

Pelotonium said:

Can you explain a bit, please, Andy.

If cycling efficiency were closely related to the pattern of force application, then you'd expect that the more efficient/more successful cyclists would pedal in a different/better manner than less efficient/less successful cyclists. Instead, what has been shown is:

1) among elite cyclists, there is no common pedaling pattern, nor any relationship between how a person pedals and their efficiency (in fact, at least one study has found that the "rounder" your natural pedal stroke, the less efficient you are);

2) on the whole, elite cyclists don't pedal markedly differently than non-cyclists;

3) #'s 1 and 2 are consistent with theoretical considerations, i.e., modeling of the biomechanics of cycling; and

4) the only studies that have specifically examined the impact of changing how a person applies force to the pedals have found that doing so results in a reduction in efficiency.

acoggan said:

If cycling efficiency were closely related to the pattern of force application, then you'd expect that the more efficient/more successful cyclists would pedal in a different/better manner than less efficient/less successful cyclists. Instead, what has been shown is:

1) among elite cyclists, there is no common pedaling pattern, nor any relationship between how a person pedals and their efficiency (in fact, at least one study has found that the "rounder" your natural pedal stroke, the less efficient you are);

2) on the whole, elite cyclists don't pedal markedly differently than non-cyclists;

3) #'s 1 and 2 are consistent with theoretical considerations, i.e., modeling of the biomechanics of cycling; and

4) the only studies that have specifically examined the impact of changing how a person applies force to the pedals have found that doing so results in a reduction in efficiency.

Thank you for this reply. I recently did sub maximal testing and a VO2max ramp test and something that I learned is that I am really inefficient on my bike. There have been a few articles I have read that indicate improving power throughout the pedal stroke will help.

I am curious where I might find a good definition of what cycling efficiency really is and what might be done to improve it.

I have tried to "evenly distribute power throughout my pedal stroke" and it only made things worse. My power dropped by ~10% on my interval work.

teebone said:

I am curious where I might find a good definition of what cycling efficiency really is and what might be done to improve it.

To improve it, you just need to keep putting in the miles, pedaling however feels best.

teebone said:

I am curious where I might find a good definition of what cycling efficiency really is and what might be done to improve it.

see:
http://en.wikipedia.org/wiki/Thermodynamic_efficiency

Hi--

Thanks for taking the time to respond with some more information. It seems my initial assumption that pedaling in 'circles' was incorrect from an efficiency standpoint. I had just assumed that it was prefered given the products like power cranks and spinscan.

Here's a report which shows no differences in efficiency for using ROTOR pedals:
http://apt.allenpress.com/aptonline/?request=get-abstract&issn=1533-4287&volume=017&issue=04&page=0785

On the other hand here's a study for powercranks which shows some improvement:

http://apt.allenpress.com/aptonline/?request=get-abstract&issn=1533-4287&volume=017&issue=04&page=0785

It just seems like there should be something better than pedaling away and doing whatever feels 'right'. Thanks again for your input.

Rob

acoggan said:

If cycling efficiency were closely related to the pattern of force application, then you'd expect that the more efficient/more successful cyclists would pedal in a different/better manner than less efficient/less successful cyclists. Instead, what has been shown is:

1) among elite cyclists, there is no common pedaling pattern, nor any relationship between how a person pedals and their efficiency (in fact, at least one study has found that the "rounder" your natural pedal stroke, the less efficient you are);

2) on the whole, elite cyclists don't pedal markedly differently than non-cyclists;

3) #'s 1 and 2 are consistent with theoretical considerations, i.e., modeling of the biomechanics of cycling; and

4) the only studies that have specifically examined the impact of changing how a person applies force to the pedals have found that doing so results in a reduction in efficiency.

rschlend said:

From my understanding there are more and less efficient ways to pedal. I'd prefer to apply the same amount of force with each leg for example. Additionally, the theory goes that applying a force throughout the pedal stroke[font=&quot] [/font]recruits more muscle groups creating better endurance, economy and balance of strength.
I live in the middle of a city and with work and life, end up cycling on a trainer at night frequently. It seems like a good time to work on pedaling efficiency. A tool that would verify I was using equal amounts of force on each leg and a method for reducing my dead-spots seems pretty useful.
Here are a few links to some articles I've read on pedaling:
roadcycling.compedalingtechnique.shtmlOpen ↗
53x12.comshowOpen ↗
pezcyclingnews.compezcyclingnews.comOpen ↗
Thanks for the question! Rob

Rob, don't let them fool you as of course there is more or less efficient ways to pedal, even though some people want to make you believe there are not - for obvious reasons.
Also, of course this can be measured and monitored although some people want to make you believe this could not be - for obvious reasons.
Simple example:
- When riding a hill, just emphasize on your downstroke more than you would
normally do or 'forget' to lift the other leg (not pulling, just lifting), and you will be exhausted in no time.
- If still not convinced, ride the hill with 'normal' pedals, no clips, no cleats.
- Change speed vigorously when riding on the flat in opposite to riding the same strip in a constant speed and you will tire much quicker.
- More obvious, take a backpack and ride uphill out of the saddle with a very small gear, i.e., in a staccato-form of pedaling and repeat the same in a smooth movement with a 'long chain'.
- Ride the same hill/intervalls in the small and in the big chainring at individual threshold or same Rpm or same speed(Watts) and you will experience the striking difference after just two intervalls already.
Only because some people threaten to drown you with heaps of literature originated by someone who has done nothing but successfuly copied what someone else has brought up, this doesn't mean its true. Maybe its scientific, but still you will be able to call them wrong within 20ks.
So far, ric_stern/RST is the only one who has the guts to come forward with one method which may assist you better than most 'modern' powermeters - force measuring pedals. The reason why some people try to make you belive they wouldn't work are again obvious.
The reason why most modern powermeters would not do the job well is originated in their poor datastream or setup altogether, not because this wouldn't be possible or work. In fact, it works to a very high degree when you know how to read the graphs and, what is even more important, know how to modify them by changing the rider's position effectively.
Keep in mind that this doesn't mean a rider would walk out of a ciclefit-laboratory and automatically burn off everyone he couldn't hold onto before. Like most things in human nature, it may take some time as neuromuscular adaptation is a process of error and reward, not a switch, as some so-called scientific tests want to make you belive - again, for obvious reasons.[img]cyclingforums.comwink.gifOpen ↗[/img]