Crank arm mounting apparatus for a bicycle

Abstract

A crank shaft unit for rotatably mounting bicycle crank arms in a bottom bracket includes, and adapters for maintaining the crank shaft unit in position relative to the bottom bracket. The crank shaft unit includes a crank shaft having connecting projections formed at opposite ends thereof for engaging inside walls of bosses of the crank arms, a cylindrical member surrounding the crank shaft, and bearings for rotatably supporting the crank shaft in inside walls of the cylindrical member. The adapters are mounted between an inside wall of the bottom bracket and the crank shaft unit. At least part of the bosses of the crank arms extend into annular spaces formed between inside walls of the adapter means and the crank shaft. Annular stepped spaces extend from the ambient to surfaces of the crank shaft through the adapters and bosses.

Dependencies are inferred from the claim text.