Other Size available: 21x3.5, 21x2.15, 18x3.5, 16x3.5, 18x5.5. Fat Spoke Front Cast Wheel: 21x3.5 Fat Spoke Wheel with 36 Fat King Spokes with Reducers and Bolts. Fat Spoke Rear Cast Wheel: 16x3.5 Fat Spoke Wheel with 36 Fat King Spokes with Reducers.