Madera Mast Helm Celestial Sprocket 28T 19mm Spline Drive
-The Madera Helm Spline Drive sprocket is manufactured from 7075 Aluminum in the USA. This sprocket requires no sprocket bolt. Instead, it has a hardened CrMo steel insert in that matches up to the 48 splines on the BB axle for pure, direct power transfer.
-Available for 19mm