Folding Bikes - un72/phil wood/twenty trouble.

i finally got those elusive and expensive phil wood bb cups today. i went to install the old un72 bb and even when the cups were tightened down as far as they would go, there was still play. does anyone know if there are different shell sizes used with the un72? mine measures about 57mm. i saw one on ebay just now with a 73mm shell. i assume that's what i need. can someone tell me if that one (the 73mm shell) is the one i want?

i finally got those elusive and expensive phil wood bb cups today. i went to install the old un72 bb and even when the cups were tightened down as far as they would go, there was still play. does anyone know if there are different shell sizes used with the un72? mine measures about 57mm. i saw one on ebay just now with a 73mm shell. i assume that's what i need. can someone tell me if that one (the 73mm shell) is the one i want?

Sorry to hear that you're having trouble. I could be wrong about this but I think that all UN72 shells are 57 mm long. What is different between a 68 mm and a 73 mm UN72 is the cups which are not used when installing the Phil Wood rings. The Phil rings have to screw in farther than the normal bb cups to clamp the bearing. The problem may be that the threads in the shell don't go in far enough or that there is schmutz from the chainstay welds in the threads that is preventing the cups from going in. On one of my 20's it took excessive force to get the rings installed, enough to oval the installation tool. If you can find a Raleigh dealer that has been in business for 20 years or more they should have the correct tap to chase the threads. Otherwise a shop may be able to make a tap from one of the original bb cups and run it in far enough to reach. Hope this helps.

hmm.. good news and not so good news. at least i've got the proper bottom bracket and the proper cups. i think i know a guy who might be able to tap those threads.

i've never spent so much time working on a bike. it's driving me slightly mad.

a-ha... upon closer inspection, i see that there are plenty of threads in there, only they've been covered up by the original paint. our local bike co-op has a 26tpi bb tap, so it should be no problem. as much as this bike/project has been a pain in the posterior, it's a nice feeling to find solutions to problems. i haven't been able to ride my twenty in over six months, could today finally be the day???

If the taps are full of paint it might be good to put some stripper/brake fluid/solvent in there and attack it with a small wire brush/stiff toothbrush first before retapping. You need to be sure the re-tapping is done with the right tpi tapper or woe will ensue.
Wishing your speed in getting it installed though. Huw

@ Andy, sometimes during my on-going Twenty project i have also almost despaired. I am glad i stuck it out, but were i to do it again or especially buy another bike i am guessing i would likely go for a lightly modded Downtube to cut back on the hassle and so i could ride from day one. But i have def. learned lots and communicated with a lot of cool people in the process (you guys among others),.. so i am not complaining!

yeah, i'm glad i haven't given up yet. would have been a bigger pain if i didn't have another bike to ride while i've been working on this monstrosity. the thing that has kept me going is knowing that when i'm done, i'll have what i want, not something i had to compromise on because of a time constraint.

the good news is that after a bit of steel wooling the bottom bracket is finally in and i just took it for a test ride around the block. after a couple fine tunings tomorrow (like getting some brake cables...) it should be good to go.