Ok, this is probably a post of interest to quite a narrow audience, but as I sit here in Koolstof Towers waiting (impatiently) for delivery of our first set of Look Power Pedals for stock (due in today), I started wondering what the general concensus is out there around pedal based power monitoring.

Last week we heard that Garmin's Vector is not expecting to hit the shelves next spring due to ongoing challenges with the crystal based strain guages, so we have decided to ignore the missing ANT+ compatibility of the Look/Polar system and back them moving forward. They look (can you see what I did there?) a lot more snazzy anyway, plus the technology seems far more proven and ready to go.

With that in mind, I wondered what others peoples thoughts are on the subject of power monitoring systems generally, is there an interest in moving to pedal based systems, or are you happy with the current cranks and hub based systems out there?

Personally, I like the idea of the Look pedals, both with regards to weight, transferrability and the ability to measure individual power output of each leg. I also like the fact that the technology is sound, so I am sort of convinced.

However as a way of a test, my colleague is off to BikeRadar tomorrow to help test the accuracy and useability of all the main power players in a controlled experiment, so the results of that may or may not change my position. Watch this space.

Oh, and yeah, if anyone is after a set of Look Power Pedals drop me a message... As you can imagine I need to offer our athletes first dibs.

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I think much of the left/right power monitoring is hype. Any gross imbalance should be picked up by other means and a small difference is totally normal.

Speed of change is also misleading. A SRM or Quarq takes about 2mins (I think there is a clip of guy doing it under a minute.)

And until it can be proven otherwise I am still to see anything that truly rivals SRM for accuracy. Quarq and Powertaps are very close. But the others all seem to suffer inconsistent variance. And this makes them unreliable training tools.

On a totally personal note I think Polar have ensured their place on the Titanic. And good ridance.

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"Physiology is all just propaganda and lies... all waiting to be disproven by the next study."
"I'm not a real doctor; But I am a real worm; I am an actual worm." - TMBG

I think pedal based power will be just about the same as every other technological improvement: "invaluable" for some, and "irrelevant" for others.
For a world-class athlete, knowing of a slight power inbalance may lead to an incremental improvement.
Even for a beginner, if they can distinguish power between sides and work on keeping it even, why not ?

If the prices are comparable, I'd buy it. I don't think would pay 30% more just to get it though.

This is the oft quoted "benefit" to the pedal based PM but I'm curious why you think it would be a benefit to know the difference between left/right power.

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"Physiology is all just propaganda and lies... all waiting to be disproven by the next study."
"I'm not a real doctor; But I am a real worm; I am an actual worm." - TMBG

left-side balance is misleading
working with Wattbike you can easily watch that:
- a 50-50% balance can be a net result of compensations
- it's more important the shape of torque than net result

So if these pedals will offer raw data analysis options (as showed on Metrigear Blog before it was "absorbed") they will add something usefull.
If they'll just offer a net balance of L+R as it seems the firmware will do at the begin (?) the value of this "technology" and its real application will be not much an improovement to what it's already on the market.
IMHO.

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I think what Tapeworm is alluding to is the fact that L-R balance has more to do with muscular capabilities than aerobic efficiency and, as we are all aware, cycling's an aerobic sport. Having both legs do equal amounts of work won't improve aerobic efficiency

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K2

Do you suffer more when you train, or cannot train?

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I cannot assert that it would be a benefit. I can only speculate that it may be a benefit.
But if an imbalance were noted, the first question would be "why ?".
If there is a real muscular difference, then it seems like strengthening the weaker side would be in order. Maybe it would work, maybe not. But you can't even get the answer to that unless you have some data that tells you what's going on.

Another thing that occurs to me is that most humans are "side dominant", such as right-handedness. Maybe there is nothing holding back the weaker side except the recognition thatb it is not working at full power. In other words, if you know your left side is lazy, you could coax more out of it just by concentrating on it.


Why bother to even buy two shoes and two pedals then ?
Save weight and pedal with one leg!

Yeah kevin touched on it. Basically all humans are asymmetrical. There will usually be a left/right discrepancy. It IS an issue if this imbalance causes biomechanical issues. Hence my point about being picked up by other means. A good fitter would (or should) pick up on any gross imbalance.

Beyond that I don't really care that I have a 56/44 power split. Even in the abovementioned situation bringing power output into "balance" will not 1) improve biomechanical function and 2) improve total power output.

The body is a system.

Good that more power systems are coming onto the market, but IMO the only reason that's good is that hopefully it will bring down the price of a SRM

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"Physiology is all just propaganda and lies... all waiting to be disproven by the next study."
"I'm not a real doctor; But I am a real worm; I am an actual worm." - TMBG

+1!

You also fail to understand what is limiting aerobic performance. It's not the power in isolation by the left or right leg.

Think about this:- if using a counterweighted crank or fixed gear and you pedal with one leg do you produce half the power (or there abouts) you would with both legs or would it be higher (65% +)?

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"Physiology is all just propaganda and lies... all waiting to be disproven by the next study."
"I'm not a real doctor; But I am a real worm; I am an actual worm." - TMBG

Yes the system has variables. An unbalanced left/right power output is of no major concern unless, as stated, it impacts on actual biomechanics. So it is an inconsequential variable. Somewhat like not "pedalling in circles".

Take the example of a person who has a 60/40 power split and consider the following questions:-

1) what is limiting them from improving the aerobic performance?
2) how would this limiting factor(s) change if power is brought to a 50/50 balance?
3) how would you achieve such a change to a 50/50 balance?

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"Physiology is all just propaganda and lies... all waiting to be disproven by the next study."
"I'm not a real doctor; But I am a real worm; I am an actual worm." - TMBG

I thought I did dismiss it. Lots of things are variables to performance but to focus on them is usually a waste of time when compared to those which make a far larger difference.

My arguement is not circular. One can have sound biomechanics whilst producing a power differential between the legs. I am surprised that the difference between biomechanics and biochemical is not more clear.

And once again, how do you think such a differential would be rectified? (actually it would be handy if you answered the questions I posed.)

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"Physiology is all just propaganda and lies... all waiting to be disproven by the next study."
"I'm not a real doctor; But I am a real worm; I am an actual worm." - TMBG

The questions are not rhetorical. I expeted a reply. Would you like me to provide the answers?

And I honestly think you don't seem to understand that one can produce differing power outputs which have zero biomechanical issues.

Perhaps if you can explain EXACTLY how balancing power output from each leg will yield a higher overall power output.

_________________
"Physiology is all just propaganda and lies... all waiting to be disproven by the next study."
"I'm not a real doctor; But I am a real worm; I am an actual worm." - TMBG

OK. You don't care if it is 56/44.

What if it is 60/40 ?
70/30 ?
85/15 ?

At some point, I think any rational person would "care".
Otherwise, I go back to my original question: Why bother to use both legs at all ? Why not just use one crank arm ? Think of the increase in power/weight ratio !

Here is EXACTLY how balancing power out put can increase power output:
1 leg - 50%
If I now start using the other leg: 100%
That is a 100% increase !

I know that is overly simplistic; but so are the arguments that it makes NO difference.

I guess the question is what do you actually do with the information if it does turn out you have a 60/40, 70/30 or whatever split? And surely if you are at the extreme with regards imbalance then you wouldn't need a power meter to tell you that?