Differences in H2 rear hubs. Early (H2/A) on right, Late H2B/C on left .
Late H2 hub is the same as Z1. Early and late hubs are interchangeable. - Brian H.

H2B/C                                                                                            H2/A

H2 and H2A rear brake plates are the same except that the 72 plate is painted black (semi gloss).
Early 72 H2 had the LONG arm AND a long arm at the pedal end.
Late 72 and all 73 had the short arm AND short arm at the pedal end.

H1/A/C

H1B

H1D

H1E/F KH500

S1/S2

S1/S2 Front

Late S Series

Late S Front (w/o Disc)