A good reason to not use clip-in (clipless) pedals [Video warning: Nasty arm break]

[Citius]

GCN couldn't do science if you shoved it up their arses and gave them a mirror on a stick to go find it.

They did say in the vid that it 'wasn't proper science' - but ironically it did correlate with what many other studies have found. Which bits do you disagree with?

 

[Yellow Saddle]

YS - the point is that Wattbike measures force downstream from the pedals and only knows the location/speed of the cranks twice in every 360deg rotation. The rest is just guesswork. It is not measuring crank force independently, so the graphs are meaningless from a training analysis perspective.

There's no question that the Wattbike gives you two graphs (one per leg) - but the data is gives you is not worth a jot, as it is not derived from a truly independent measurement. The Wattbike is a great tool for many things, but it doesn't give you independent pedal stroke analysis in the way you think it does. Plenty of discussion over on BR and other forums, training blogs, etc, about this.

Interesting link here: http://alex-cycle.blogspot.co.uk/2013/11/left-right-out-of-balance.html

OK, it seems as if I'm out of my depth here. Let me go and check out what's what.

 

[Drago]

They did say in the vid that it 'wasn't proper science' - but ironically it did correlate with what many other studies have found. Which bits do you disagree with?

The title - "GKN does Science". They're doing nothing of the sort, their methodology and analysis being so poor that any correlation with anyone else is little more than a statistical inevitability rather than a conclusion deduced.

 

[Citius]

The title - "GKN does Science". They're doing nothing of the sort, their methodology and analysis being so poor that any correlation with anyone else is little more than a statistical inevitability rather than a conclusion deduced.

Their methodology and analysis seemed perfectly ok to me - treadmill, gas analysis, blood lactace - all lab measured and they presented their findings without any obvious bias and without reverting to anecdote. What was lacking (quite obviously) was a decent sample size. I would have been more concerned if their findings went against the accepted evidence - but they didn't.

 

[Drago]

Sample size is a biggie, as is the number of subjects. Even basic stuff like calibration of equipment has to be accounted for else its pointless trying to call it science. Then there's air pressure, temperature, humidity, more variables that require accounting for that I should shake a stick full of cleats at.

 

[Yellow Saddle]

OK, I'm back after reviewing the excellent link Citius provided. I was mistaken that the Wattbike uses a strain gauge on each crank, but it seems it doesn't and I understand now how they fudge the power balance graph between left and right leg.

However, the thread is about being clipped in and the debate, I think, started off as clipped-in being a way of generating more power by way of applying force more evenly throughout the pedal stroke and how being clipped in can help with that. A short little trip to work last night up a country lane perhaps demonstrated what I get out of being clipped in. I'm usually - no, always, clipped in. However, last night I just hopped on the bike in my work shoes, stomped on the mountain-style SPDs and pedaled. As soon as I applied a bit of power I felt my foot slip off backwards, which indicated that I do pull back at least a little bit. But that happened only once and my brain cottoned on to what was going on and I changed my pedal style and it didn't happen again without me even thinking about it.

From an engineering point of view, applying power over larger parts of the circle is a bit like a one-cyclinder engine vs a 6-cyclinder one. Whether the latter is more efficient (negating all the added friction from the many pistons) than the single pot popping up and down, I have to think about. My thinking is that the slow, pulsed power inputs waste energy trying to accelerate the large body with plenty of inertia in slow pulses rather than faster, smaller ones spaced out around the rotation.

 

[buggi]

If you think unclipping takes a measurable time longer to put your foot down, then something is wrong, but not with the pedals or cleats.

Agree. It takes me longer to put my foot down on my MTB (flats) than my road bike (clipless) simply bcoz of how wide the pedal is. On clipless, the second you unclip, your foot is no longer on the pedal.