Early 1971 Commando rear wheel bearings

Unless you have a bolt on sprocket you need three bearings.

The bolt on sprocket / brakedrum has the third bearing which stub axle locates in without this your wheel would float around as axle slides through other 2 bearings.

So is bearing still on stub axle?

Most pre-1971 Commando bikes would have used a rear wheel set-up that was similar to the Atlas. ie. a brake/sprocket bolted via 3 studs to the hub. The hub containing just two bearings for the axle. A single ball race and a double ball race.

The significant difference between the Atlas and early Commando rear wheels being the use of an 18" rim for the Atlas and 19" for the Commando. Plus UNF threads on the Commando brake drum and only 42 teeth on its rear sprocket. The Atlas having Cycle threads and 43 teeth.

After 1970, the Commando brake/sprocket became the vane type, with cush-drive rubbers set inside the hub. Because these rubbers allowed the hub to flex in this area, a third internal bearing was added to give support. Unfortunately, the power delivered to the sprocket still tends to pull the sprocket out of alignment and this extra bearing then gets a hammering.

Having recently had to pay some attention to my rear sprocket/brake drum of the bolt up variety, I noted that the boss at the base of the three threaded studs, varies in diameter. Two are smaller and the third is larger and a close fit into whichever hole it is located. Originally I presumed wrongly that all three would be locating the drum onto the hub but only one is doing any locating. the rest is taken care of by the taper of the three sleeve nuts. My need to investigate an eccentric running brake drum was down to the previous owner boring the bearing spacer out to fit a larger spindle.

On the access Norton forum there is a chap in the Philippines that supplies one piece rear spindles for the cush drive rear wheel. It seems in the States where the majority of Commandos went, there is some history of rear wheel spindle breakages.