Bicycle Mechanics - Differences b/w Dura-ace cranks 7400,7402, 7410

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ebbett
11-24-03, 01:34 AM
Does anyone know the differences between the Dura-ace cranks 7400, 7402, 7410. Are these numbers just part of the product packaging or do they actually relate to some kind of measurement. The seller is listing a 7400 left crank arm, 7402 right crank arm, and a 7410 right crank arm. I initially thought that the 7402 and 7410 right crank arms related to the bolt circle diameter, but in the description for both the right arms, the bolt circle diameter is listed as 130.

Also, are all these cranks the old taper style? I need to get both a left and right arm. If I get the 7400 left crank arm, which model right crank arm do I need?

Thanks.

Gonzo Bob
11-24-03, 06:22 AM
The 7400, 7402, 7410 are the model numbers. I have a bike with 7400 (6-speed) and a bike with 7410 (8-speed). All three take a square tapered bottom bracket axle but if I remember correctly, the 7410 requires a shorter BB axle than the 7400 or 7402.

The 7400 and 7402 are almost identical in appearance while the 7410 has a more rounded look and has the main arm starting out much closer to the spider arms and angling out before straightening.