Crank length

[ratz]

What BCD do You have?

I have 110BCD; the 130 would be better in most cases.

Shimano Ultegra might be an issue; don't like their four bolt cranks at all so I haven't looked at one of those.

 

[brokemyback]

An effective pedal stroke will actuate the pedalers ankles, knees, and hips through acceptable ranges. Too short and you're spinning your feet wildly in circles devoting all your energy to changing the momentum (accelerating) your legs instead of putting power to the pavement. Too long and your knees and hips bend so much you lose leverage (crouch down low so your butt gets close to the ground (large joint angles) and see how hard it is to stand back up). The exact ranges of angles that works well with your body takes experience and fitness. When choosing crank length keep these things in mind:

• Your x-seam. Longer legs means longer crank length.
• Hip angle. More closed hip angles produce greater power from lower cadence and longer cranks.
• Ankle actuation. The more you point your toes at the end of the stroke the longer crank is needed for bending of other joints. In my experience I point my toes much more with a clipless setup (as compared to platform pedals).

To the original poster's question ... this explanation here is logical. I haven't experimented with different (shorter) crank arms, but the theory of shorter cranks for long X seam riders sure doesn't make sense.

 

[snilard]

That's a good question. It should; the Power2Max one does and they are very similar on the back side design; from photo graphs the PowerTap C looks to have a slightly bigger opening; but I'm guessing a quick email to them would confirm the inside diameter. The Power2Max ones are Spindle specific so they designed tight to the 24mm bearing cups. Since the PowerTapC is spindle agnostic they had to account for BB30 external cups without screwing up the Q factor. Hence I doubt there will be a problem .... but until someone tries it....

Point of detail thought; the Yellow V's the clamp was bigger and I had to get cut with the left right offset by 2mm to get it to work; on the the new V20's the clamp is more refined and I had no fit issue there is a good 1.5mm clearance which is fine for such things. On the Silvo's there is a massive amount of clearance.

How did You offseted crankset? Is there some washers to be used for this purpose?

I am thinking about Powertap G3 or C1 powermeter, others are out of game with my 150 mm cranks and Speedplay Frog pedals. Cost would be nearly same with my prefered rim and spokes. What I don't like on C1 is apearance and 36 tooth ring. On G3 I don't like that I will have to say goodby to my nice DT Swiss hub and it will be locked to one wheel.

I am sorry for off-topic.

 

[ratz]

How did You offseted crankset? Is there some washers to be used for this purpose?

Offset the chain stay clamps so that on the non drive side you BB cup is flush with the out edge of the clamp. That pickup up about 2-3mm on the drive side which gives just enough extra clearance.

 

[snilard]

That's a good question. It should; the Power2Max one does and they are very similar on the back side design; from photo graphs the PowerTap C looks to have a slightly bigger opening; but I'm guessing a quick email to them would confirm the inside diameter.

50 mm. I think that without offseting chain stay clam It will be impossible and with offset it will be so so. I am thinking of trying it, dealer offered me test.

 

[ratz]

50 mm. I think that without offseting chain stay clam It will be impossible and with offset it will be so so. I am thinking of trying it, dealer offered me test.

I can pull the power2max off tonight and measure it after dinner. Give me 2 hours and I'll get you the I.D. measurement.

 

[ratz]

60mm on the power2max; I don't think 50mm will fit.

 

[snilard]

60mm on the power2max; I don't think 50mm will fit.

Thank you, Ratz. That is bad message for me. While I may get PowerTap C1 now, for PowerTap G3 I have to wait because I wand dual ANT/BLE electronic and they don't sell it yet.