Stopped at the bike co-op the other day to swap out the cog on my 1975 SA AW (a 22 for the original 18 or 19).

Last step, re-attaching the non-drive side of the wheel: I experience the sickening feeling in which the nut tightens up, then suddenly becomes much easier to turn. The sucka is stripped!

OK. No problem. I retrieve the box of 500 axle nuts, thinking, I'll just grab a quick replacement.

10: Does nut fit? If "Yes" GOTO 30. If "No" GOTO 20.
20: Put nut in reject pile. Select new nut. GOTO 10.
30: End

I never got to 30.

After about 20 minutes of hope and denial, I searched the place for some Loctite, but found only Rubber Cement.

So I cleaned up the axle and original nut, rubber cemented it in place, and rode home.

Do I need a special nut, or am I nuts, or what?

Eric

P.S. I like the new, slightly lower gear range. Before, I spent most of my time riding my Schwinn Speedster in "1," using "2" only going down hills, or once I had the 70 lbs of steel up to speed. Now I use all three gears. Unfortunately, my wrenching seems to have introduced a periodic, chain-related {kerchunk}, which I need to investigate.

P.S.S. How long will my rubber cement hold?

#1: EDIT: See Mark's post below.

#2: Left-hand SA axle nuts will strip on the 3rd time they're installed. If not the third, then the second.

#3: Sourcing an NOS left nut isn't easy. For reliability, just stick a right-hand nut in place; for looks, grind down the same right-hand indicator nut and file smooth. Keep in mind that the filed-down indicator nut will strip just as easily as the standard LH nut!

-Kurt

#1: SA axle nuts are a special case of BSC (British Standard Cycle) thread. BSC was 26 tpi for most sizes as the fine pitch produces more tension on the fasteners, so they were less likely to loosen from vibration. BSC was used on both motorcycles and bicycles. There was no 13/32" mentioned in the BSC standard but the axles have 60 degree threads, unlike the 55 degree threads of Whitworth. A "Complete" set of BSC taps and dies does not include 13/32".

There never was a Whitworth standard for a 13/32" thread either. But since the 3/8" Whitworth was 16 tpi and the 7/16" was 14 tpi we can assume that any 13/32" Whitworth thread wouldn't have been 26 tpi.

#2: I must be one weak-assed sum***** as I've NEVER stripped a Sturmey axle nut. Not even the cheesy, pre SunRace Taiwanese knock-offs.

#3: I you can't find any locally, PM me. I've got boxes of them.

I'm NOT nuts!

Thanks Kurt and Mark for a richer haul of information than I had hoped for (or in the case of Mark's post, can even understand).

I think I can find a right in the 3-speed parts box.

If not, Mark, you'll be hearing from me. Thanks again!

Eric

Those nuts are on eBay all the time.

Care for a box of stripped nuts? I've got 8 left-hand nuts in a can to remind me of the fact that they do. Mind you, once I learned about this problem (two nuts stripped), I was most gentle with them (not that I torque them down either). 6 more stripped, as you can see.

I'll take you up on that offer someday...

-Kurt