US Patent 10066673 Bicycle crank assembly

A bicycle crank assembly includes a sprocket having a rotational center axis, a crank, a crank axle and a slide mechanism. The crank axle is attached to the crank and includes an internal space. The slide mechanism is configured to displace the sprocket relatively to the crank in an axial direction parallel to the rotational center axis. At least part of the slide mechanism is disposed in the internal space of the crank axle.