you will destroy the chain stays and the drop outs. especially if you are just learning to grind or havent been grinding long. You have to remember it is a RACE frame made for racing... not freestyle riding or grinding. Its not made to take the hits and abuse that a freestyle bike is made to handle, it's made to be light and fast on a smooth dirt track with flowing doubles and tables, not big dirt gaps, quarter pipes, or grinding rails and ledges.