A bicycle comprises a wheel-supporting member having an annular sleeve portion, a stub wheel spindle having a journal portion supported for rotation in the sleeve portion by thin wall, large diameter angular contact bearings, a wheel attachment portion extending laterally out of the sleeve in cantilevered relation, and a wheel having a hub received on the wheel attachment portion of the spindle. The wheel attachment portion of the spindle and the wheel hub have mating tapered surfaces so as to provide precise alignment of the wheel and mating splines so as to couple the wheel to the spindle for rotation. The wheel is fastened to the spindle by a split tapered collet and a latch mechanism that holds the collet in place and is releasable by operation of a single member.