Pegs BMX Axle extenders for Grinding, Freestyle and Flatland. These BMX Pegs attach to your front and rear axle and allow you to do some grinding tricks. The front is usually 3/8″ axle size and the rear is 14mm. Many of the pegs include axle adapters so the pegs can fit either size axle. If you are not sure which brand to get, try the Odyssey Pegs.