Quoted post said:Originally Posted by maydog [IMG]/img/forum/go_quote.gif[/IMG]
I love clipless, but I suspect that 20% to 30% number is overstated and pulled from the air. I think that the big advantage for clipless vs. a regular platform pedal is that you need to focus less on keeping your foot in the right spot when pedaling hard, in a high cadence or hammering out of the saddle.
+1, secure attachment to the pedals is great for bike handling and safety reasons and it does let you pedal with a consistent and known relationship to the pedal which likely improves efficiency over someone moving their foot all over the place and randomly mashing with their toes, arches or heels but 20% to 30% efficiency improvements... unlikely.
One look at published pedal force curves from Kautz or Coyle and it's clear that rider's, especially national level elite racers do NOT spin smoothly around the pedal stroke or generate significant power by pulling up, scraping mud or otherwise doing the things that firm attachment to the pedals is supposed to allow:
Kautz SA, Feltner ME, Coyle EF, Baylor AM: "The pedaling technique of elite
endurance cyclists: changes with increasing workload at constant cadence".
International Journal of Sport Biomechanics 7:29-53, 1991.
Coyle EF, Feltner ME, Kautz SA, Hamilton MT, Montain SJ, Baylor AM, Abrahams
LD, Petrek GW: "Physiological and biochemical determinants of elite
endurance cycling performance". Medicine and Science in Sports and Exercise
23:93-107, 1991.
But I still wouldn't race without good pedals and sure clipless are much more convenient and comfortable than toe clips and straps but IMHO their real value is related to bike handling, cornering, safety on rougher roads and other times where you can take advantage of a secure shoe/pedal connection to use body english to steer with your hips, angulate and countersteer into turns, bunny hop small obstacles easily and stay firmly connected to the bike when you hit unexpected potholes or road transitions. Pretty darn useful for full out sprinting without any concerns about losing contact with the pedals as well.
A good shoe/cleat/pedal system is a really good idea but the efficiency claims tend to be unsubstantiated and there's plenty of folks doing long hard rides including long hard technical off road rides with platform pedals and doing just fine that way.
-Dave