Kasai Dnyacoil Hub 15mm ISO 6-Bolt Dynamo BlackEfficient and FIELD SERVICEABLE dynamo hub for 700c, 650b, and 26" wheels. Meets German StVZO standards (K1280). Impressive efficiency: 72% at 10mph. Most dynamo hubs are sealed at the factory and cannot be repaired by the roadside or in a bike shop. These hubs need to be cut off the wheel and must be sent back to the factory. Note with the Kasai FS Dynacoil. The bearings and the entire coil assembly of the Kasai FS can be replaced using two simple