The most expensive part in this assembly is the Drum Assy,rr Brk,buff.
Some items from this specific schematic: Rear Sprocket 34t, Pin-cotter,3.0x25, Washer,sprocket Lock, Chain,drive,ek428 96l.
The Bolt-rear Sprocket is the most widely applied product in the KM100-A7 KM100 1981 USA CANADA / MPH KPH REAR HUB/BRAKE/CHAIN ( four times ).