Patent ID: 7744498

Claim:
A derailleur-type transmission for a bicycle, the transmission being mountable to a frame of the bicycle, said transmission comprising: a transmission case, said transmission case being dividable into left and right cases, the left and right cases of the transmission case being provided with left and right bosses, respectively, the left and right bosses coaxially projecting inwardly of the transmission case; a derailleur shaft, said derailleur shaft surrounding the left and right bosses and being supported by the left and right bosses; and a derailleur mounted to an outer periphery of said derailleur shaft and disposed inside of the transmission case, wherein the left and right bosses are formed with holes therein, and the left and right halves of the transmission case are connected via a connecting member fitted into the holes; and wherein the width of the left case is different from the width of the right case, the boss on the side of a wider one of the left and right cases has a longer projecting length and is provided with a through-hole, while the boss on the side of the narrower case has a shorter projecting length and is provided with a blind hole, the blind hole is formed with female threads, and the connecting member has male threads that are threaded with the female threads.