Reader Jens A. asks: Is there a difference between 9-speed and 10-speed cranks? I myself ride a 3x10 drivetrain and would like to buy a new crank. However, there is no information on the new crank. So it doesn't seem to matter, does it? The bearing and the number of teeth are identical.
Answer from the BIKE expert: In terms of dimensions, 9-speed and 10-speed cranks are almost identical. They have the same chain line and the distance between the chainrings is also the same. The main difference is the optimisation to the respective chain. 9-speed chains are wider due to the flared outer plates. The position and shape of the shifting rivets and grooves on the chainrings are precisely matched to this. If you combine the two, you risk poorer shifting performance and a greater risk of chain jamming.
