Single Speed 45T/47T/53T/56T/58T 170mm Crank Arm Mountain Bike Chainset 130BCD .
Specifications: 45T 47T 53T 56T 58T; standard 130mm BCD; 170mm Crank Arms. Length: 170mm. Crank Arm Compatible: single 3/6/7/8 speed chain. The chain must be lengthened if the larger chain is replaced.