Wheels

The rear wheel has a broken spoke. Also noted is the spokes are bending because other spokes interfere. It appears to be not laced correctly so the spokes are fighting. Stress is a likely cause of failure.

Note big curve in the spoke as it crosses over 3 spokes. Studying...

Same here, another pic

1Dec2108 Update: I was able to improve the spoke bend/curve problem but not eliminate it completely. All of the spokes have a natural bow because of the way they attach at the "hook" end. 

Wheel bearings were USA made Timken tapered rollers. They were washed and repacked. I need grease nipples for the hub (bike has 8 nipples missing 5/16'' x 32tpi)

Update: I bought one Chinese made tapered roller off Aliexpress. Cup and cone. Appears good. It was 1/5th price including shipping!! Will be monitoring it closely.

Grease nipples arrived. Wish I bought 1 extra. Anyway I'll never grease the wheel bearings because excess grease ends up on brake linings. These may as well have blanking plugs instead.

Rear wheel spacers made to achieve correct chain alignment within half a millimeter. I had to account for a slight variation in sprocket thickness.. RH spacer 7mm, LH 13mm

I used an old fluorescent tube as a straight edge to get the back wheel true to the vertical frame tubes.

Attempting to lace the front wheel going by the book,  drum flange needs to be 1-1/8" offset from the rim edge. Therefore my spokes are too short. Shop manual lists them as even shorter! 

Update: The quoted offset isn't correct, at least not for my bike. Neither is the quoted spoke length.

The rims are quite roughly roll-formed at the bead. It's not possible to be 100% accurate with truing or wheel alignment because of this. Near enough had to be good enough. At this stage I'll road test and determine if I move the alignment any more.

I found different types of spoke nipple as removed from the wheels. The spoke threads are roll formed.

Theory of thread engagement says when a nut screws onto a bolt up to 1.5 times its' diameter , the thread purchase is as strong as bolt itself. I have at least 6mm of thread engagement on the worst ones. The spoke thread diameter are about 3.8mm (from memory)

20Nov2018

After several hundred kilometers I found another broken spoke on the drum side, the same side as what broke before. The plan is to remake all the drum side spokes, all 20 of them. I'm not remaking the drive side spokes because they are significantly easier to replace in situ and I'll have 19 spares now. New spokes will be made 3 ~ 4mm longer The plan is for spokes to be ready to pick up Friday...

Thinking about why these spokes are breaking it occurred to me, replating old spokes with zinc is known to weaken them. Additionally, the spoke maker said he's seen more spokes broken on the drum side as opposed to the drive side. Hopefully fresh spokes will sort the problem.

29Nov2018

The wheel is all fixed with 20 new spokes to the drum side. I went with 20mm offset.

There was some drum spoke holes TIG repaired because they'd been elongated.

In addition the brake torque stay needed tweaking to prevent it from being under stress. I didn't bolt it down solid either, rather I left it slightly loose but with a spring washer as an "anti-rattler". I inserted the split pin in the castellated nut as per normal. 

The front wheel was centered in the forks by moving it 1.5mm to the left. I used shims to achieve this rather than using the spokes to pull it across because they were already short.

Road testing shows the bike very stable. It tracks true and I can ride and steer without hands on the handlebars.

28June2019 Update: The drum side spokes have broken 4 spokes so I'm rethinking the setup.