It's a little bit of a bodge, but hey, if it works, it works.

Here's a description of my bodge, and it seems to work just fine. I read rhm's post in the thread http://www.bikeforums.net/showthread...raleigh+twenty , and realized that he was exactly correct- after rethreading the BB shell, you would only have 3 good threads left. I really didn't want to alter my BB too much, and I'm way too cheap to buy Phil retaining rings let alone Phil's whole bottom bracket assembly. Anyway, I hear horror stories about the threading in the shell being too shallow for the Phil cups, etc.

So, first I ground away 3 mm of the BB shell to make it 73 mm wide, taking care to dress it flat and square with a file (no BB shell facing tool). Then I ground all but the last three rows of threading from the right-hand side of a 73 mm Shimano UN54 BB, making sure to not crush the transition threads, dressing them up with a needle file. Then I ground and filed most of the threading from the left-side (plastic) retaining cup, leaving more material since it's alot softer than the BB shell and a tight fit is good. Here are a couple of pics:


A rethreaded BB shell and a 24 TPI cup installed. Note only about 3 good threads every half-inch.
(thanks to rhm)



My modified BB, retaining 3 good rows of 24 TPI threading on the body, filing away most of the threading on the plastic retaining cup.



The BB installed. The body screws in easily, and the cup is a bit snug, as it should be. No creaking or clicking (yet). Total cost: 20 bucks and about a half-hour work. Another good thing is that the original cups and axle still work fine, too.