They are perfect for grinding, the shape is such that they won't roll around and they are nice and flat so they fit well. Just be sure that unless you are buying the 140mm cranks they come with a washer that fits inbetween the crank and the pedal otherwise the part that holds the pedal into the crank will come crazy loose after big drops and lots of grinds and your pedals will be slanted down all the time. (like mine)
Also where are you planning on buying your hub/crankset?
