A sample from the products for the Rear Wheel include: Collar B Axle, Collar,axle Dist., Bolt,chain Adjust, Tube375/400-18tr6.
The most reasonably priced component used on the Cb550 Four Cb550k3 1977 Usa Rear Wheel is the Nut.hex 10mm.
In this schematic the "Spoke Bs, 8x144.5" is used most often.