Abstract: The invention relates to a mounting system for mounting a drive unit on a bicycle frame, wherein the mounting system comprises an adapter which consists of at least one part, but preferably of two parts (7, 8), and which has variable attachment points (9, 10), to which a drive unit (comprising a motor and a controller) is fastened, wherein the adapter can be fastened on the bicycle frame using the attachment elements (12).
Abstract: A crank set for a bicycle includes a free-wheeling device having holes for attaching chain rings. The holes include two separate circular bolt hole patterns L1 and L2.