FSA SL-K Armset

These arms are specifically designed for e-bike systems that utilize an ISIS bottom bracket interface. Before purchasing, verify that your motor system uses the ISIS standard, as they will not fit systems requiring square taper or proprietary splined interfaces.

Carbon fiber offers a superior strength-to-weight ratio compared to aluminum. On an e-bike, upgrading to these arms helps reduce rotational weight, which can make the bike feel more responsive and agile on the trail without compromising the durability needed to handle motor torque.

Crank length is largely a matter of personal preference and bike geometry. 172.5 mm is a standard length that works well for most riders, but if you are currently using 165 mm or 175 mm arms, you may notice a slight difference in your pedal stroke and ground clearance.

No, this product is the crank arm set only. You will need to ensure you have a compatible ISIS bottom bracket installed on your e-bike frame to mount these arms.

No, these are engineered specifically for the unique torque demands and spindle interfaces of e-bike motor systems. They are not compatible with standard bicycle bottom brackets or drivetrain setups.