Shimano SM-EWSS1 Speed Sensor Magnet Adapter The Missing Piece If your STEPS-powered e-bike runs a 6-bolt rotor instead of a center lock rotor with a built-in magnet, the speed sensor has nothing to read. The SM-EWSS1 fixes that. It mounts between the rotor and hub, giving the EW-SS301 and SM-DUE11 speed sensors a clean, reliable signal without swapping your rotor or hub. It installs with the six supplied fixing screws, sandwiched between the rotor and lock washers, and that's all there is to it. Features6-bolt magnet adapter adds speed sensor compatibility to standard 6-bolt rotors Compatible with EW-SS301 and SM-DUE11 speed sensors works with common STEPS drive unit setups Rotor compatibility fits SM-RT66, SM-RT56, SM-RT26, and many standard 6-bolt disc rotors Includes six fixing screws torqued to 2-4 N m for secure installation alongside the rotor | Shimano | Sm-Ewss1 Speed Sensor Magnet Magnet (Rotor Not Included)