Rocking Torque (pedaling efficienty)

[Paul_nl]

Rocking Torque:

Biomechanical studies reveal that to achieve maximum pedaling efficiency, the ball of the foot must be as close as possible to the pedal axle. With the foot closer to the axle, there is less "rocking torque". Rocking torque reduces pedaling efficiency and power. "

With Speedplay Zero pedals and Sidi shoes your metatarsal is only 8.5 millimeters above the pedal axle. That is less than half the distance with Shimano Shoes and Look pedals that are at 22mm. This results in over 50% less rocking torque. Even if you don't use Sidi (or Carnac) shoes your metatarsal is still only 11.5 mm above the pedal axle. The only brand that comes close is Time when used with their own brand shoe, and it still a minimum of 6.5 mm higher than the worst Speedplay Zero combination. Speedplay Zero pedals offer the lowest rocking torque and most direct power transfer of any pedal system by a substantial margin. You will go faster with the same energy using Speedplay Zeros.

http://www.bikesportmichigan.com/reviews/speed0.shtml

Not about weight. But about rocking torque.
Where can I find more information about rocking torque and different shoes and pedaling systems?

I use Shimano Dura Ace SPD-R SL pedals and Shimano R150 shoes. Which shoes or pedals do have less rocking torque? Speedplay? Time? Shimano SPD-R SL? Look? Or others? And what about the shoes? Carnac? Sidi? Shimano?

What do you guys prefer?

[martin]

Rocking Torque:

I use Shimano Dura Ace SPD-R SL pedals and Shimano R150 shoes. Which shoes or pedals do have less rocking torque? Speedplay? Time?

the lowest pedals of all time must have been the ancient Shimano AX
http://www.shimanoax.com



but before you put out your chequebook and start searching ebay: mind they have an extra large thread and will only fit AX cranks...

Martl

[Paul_nl]

But does somebody know it for clipless pedals?

I have found this:

Time Impact 7.7mm with Time Shoes
Speedplay Zero 8.5mm with Sidi Shoes

[martin]

But does somebody know it for clipless pedals?

I have found this:

Time Impact 7.7mm with Time Shoes
Speedplay Zero 8.5mm with Sidi Shoes

Keywin http://www.keywin.com are noisefree, lightweight and inexpensive. They are pretty tow, too. I rode them the last 2 years and have to say i like them.

Martin

[asphaltdude]

I have Nike poggio's and they have a really thin sole......

[Cyco]

Back when I was running Diadora pedals (early 90s- they were great pedals) they sugested measuring from axle to inside of sole. This had the habbit of making Time and Carnac (the only shoes at the time you could mount Speedplays to) look really bad.

IIRC the measurements were along the lines of
Diadora/Diadora 9.5mm
Speedplay/Time 15mm
Time/Time 15.5mm
Look/Shimano(Carbon) 20.5mm
Look/Carnac 23mm

[ras11]

More info on "rocking torque" please. Does anyone have detailed info on this subject. It's hard to think changing pedal distances by a few mm is going to effect things that much... Can anyone quantify this ? Or is this just more marketing crap!

[Paul_nl]

More info on "rocking torque" please. Does anyone have detailed info on this subject. It's hard to think changing pedal distances by a few mm is going to effect things that much... Can anyone quantify this ? Or is this just more marketing crap!

I do not know I big the difference will be. But think about this:

Remember when you were a kid and you had a tricycle with those red, wood pedal blocks on them so you could reach the pedals? When you pushed down hard on the pedals the darn things wanted to jump out from under your feet and spin around. Maybe you banged up your shins a couple times. That is rocking torque. The harder you pressed, the more the pedal wanted to dive out from under your feet.