Helix Core e*spec cranks give your e-bike an upgrade with high-end integrity and aesthetics at a great value. Engineered for e-MTB strength, so you don't need to worry about pedal strikes or holding back on your next gravity run. Forged aluminum arms keep you confident on the trail, while alloy self-extracting crank bolts mean efficient routine service, and minimum added weight. Added details like pedal washers, molded impact boots, and e-rider preferred shorter lengths deliver all the high-end features you'd expect from a crankset well over its price. Helix Core e*spec Cranks are available in 24mm ISIS for a variety of popular motor systems, or 30mm ETOR for Fazua Ride 60. Cranks for ISIS Spindle Motor Systems are available in 21.5mm and 26mm offsets, to customize fit, Q-factor, and ride feel. - 26mm offset cranks are optimized for Bosch CX Gen4/Gen5 motor frames, but will fit on all ISIS spindle motors. - 21.5mm offset cranks are designed for optimal fit with Bosch SX, Brose S-Mag, Avinox, TQ HPR50 and Specialized 2.2 & 3.1