Bicycle crank unit comprises spindle with ball race, sealing joint and positioning ring at ends and chamfered sleeve and threaded ring on outer side

摘要

The crank unit comprises a spindle (1) which has at its ends a ball race (3), a sealing joint (4) and a positioning ring (5). On the outer side is chamfered sleeve (6) and a threaded ring (7). The outer ends are provided with two crank arms (8). The two ends of the spindle have external threaded portions (11,12). The two crank arms comprise a fixing head (81), a round bore (83) and a coupling sleeve (9).