Rear sprocket/brake drum

After a rewiring job I am reassembling the rear end of my '74 Commando and I'm concerned that the brake drum/sprocket is very loose and wobbly without the wheel and long right side axle (group 20 part #2) installed. It's been quite a while since I disassembled it (being colorblind and rewiring don't make for a quickly accomplished job) and I can't remember if it was that way on disassembly and "That's the way they all are, Sir." I can find no mention of this "feature" in any of the service manuals at my disposal (Haynes and NV factory loose leaf manual) so I searched here and I found this:

March 18, 2020
With the right hand bolt/axle removed from the wheel etc, the drum will wobble around. The left hand axle bolt doesnt hold the drum, until the main through axle bolt has been fitted and tightened. Is that what you are looking at. Thats the way it is designed.
Dereck

It just seems so...wrong. When I turn the sprocket it doesn't feel as smooth and friction free as I would expect either. The bike has about 10K miles on it and has led an indoor pampered life and almost no rainy rides so I don't feel the bearings should be shot just yet. When I push the drum/sprocket in flush and apply the rear brake the drum tightens up and feels like I would expect it to feel (no wobble) without the brake applied. Anyway can someone please reassure me that this is normal and all is well so I can install the wheel and move on to the other things on the to-do list so I can get this bike off the lift and running again. TIA

When the LH stub axle nut is tight on the swing arm, it still does not have any clamping action between the brake drum bearing and the stub axle.
The stub axle is however installed first and is held captive within the drum, but not tight, then the bearing is pressed in the drum. At this point the drum flops around. Only after every thing is tightened can all the parts get positioned and clamped. Next the brakes, drum bearing and wheel bearings can be evaluated for rotation which also now includes the speedo drive.

ADDED: after the axle is clamped the LH stub axle nut should be loosened and re tightened WHILE the rear brake is held tight which centralizes it. now with the brake released it usally rotates without brake shoe drag.

+1 Dynodave.

If you want to see the brake drum not wobbling around without the rear wheel in place just stack spacers, or make one, that will fit snugly between the exposed drum bearing and the right leg of the swingarm. Do make sure that your spacers or spacer butts up against the bearing and swingarm so that you do not end up bending the swingarm.

Best.

Of course its going to wobble without the wheel fitted, everything has its place.

The short "dummy" axle is a loose fit in the brake drum, and relies on the two bearings in the wheel hub and the long axle to hold everything in place. The design objective was to make it easy to change the rear wheel, but some folks see it as a weak design, and have changed to a single full length axle.

Also be sure the speedo drive is not binding. You can clean it and re grease it then see how free it spins while it's off. Like others have mentioned. Keep the brake engaged lightly while tightening the Dummy axle first and then the long axle to center the shoes in the drum. About 50 or so lbs torque on the long axle. You can put a spacer between the brake pedal and footrest to keep the brake engaged while you torque.

With the sprocket / drum unit out of the bike, simply screw the axle in to the the left hand (dummy) portion, put your thumb against the spacer that is in the bearing on the inner drive prong side. That thumb pressure will pull the dummy up against the bearing.
The drum unit should have next to none or minimal movement when rocked axially which would suggest the bearing is fine (as long as it spins smoothly)
As posted once installed the dummy portion which is not directly spigot ed into the bearing will be fine.

Have you ever replaced the grease in the bearings?Even though it has only travelled 10k and no rain the grease will have dried a little in 47 years so maybe regrease .

Thank you all for enlightening this dummy on the dummy axle. I will repack bearings and then I can bolt it all together without worrying something is wrong.

March 18, 2020
With the right hand bolt/axle removed from the wheel etc, the drum will wobble around. The left hand axle bolt doesnt hold the drum, until the main through axle bolt has been fitted and tightened. Is that what you are looking at. Thats the way it is designed.
Dereck

Hasn't changed.