What Our Gearhead(R) Experts Are Saying: "I've run these cranks on a Bosch Gen 4 E-MTB and they're exactly what I want for aggressive trail riding. They feel stiff under power, shrug off rock strikes, and the shorter length options really help with clearance in technical terrain. For the weight and durability, they're an easy choice for an E-bike build."When we're pushing hard on technical climbs and charging through rock gardens, the Race Face Aeffect R E-MTB Crankarms keep our power grounded and our lines clean. Designed specifically for modern E-MTB riding, they deliver the confidence we need when torque is high and terrain is unforgiving. With a clean, purposeful look and trail-ready durability, they're made to handle everything from all-day backcountry loops to bike-park laps. Built from burly 7050 aluminum, these crankarms balance strength and weight for aggressive E-bike riding. Optimized for the Bosch Gen 4 drive system, the ETOR interface ensures seamless motor integration and efficient power transfer. Shorter crank length options improve pedal clearance on rocky trails, while refined ergonomics keep our pedal stroke smooth and controlled when the motor is pushing hard.