Are pedal washers necessary on a carbon crankset?
If the instructions that come with the pedals tell you to use the washers with carbon cranks then you should do it. The reason for the washers is that that they keep the axle from rubbing against the crank and thus damaging the carbon when tightening the pedals.Oh yes, and you can compensate the thickness of the washers by moving each cleat 0.5mm outside.