R20 bottom bracket question?

[gruffydd]

I am in the process of restoring a R20 folder. I have had it powder coated (British racing green). I installed the original fork with a new headset, a new seat post with a B-17 saddle. I have the Sturmey Archer 8 speed hub on the way that I will lace up and I am planning on using the original front hub since it cleaned up nicely. Here is the problem. I found a Shimano UN 72 bb and I ordered the Phil Woods 26 tpi retaining cups. I can't get the bloody bottom bracket tight. I don't think the cups go in far enough?

Should I try to extend the existing 26 tpi threads farther into the bb shell? Can anyone do that?
Or should I just have the shell re-threaded to the more modern 24 tpi? Any suggestions appreciated.

[LittlePixel]

They're pretty tight - are you sure they can't go in further - with a bit more leverage on the tool maybe?
Those rings have gotta be a lot stronger than the frame's steel so even if there aren't threads to quite the depth you need then fitting the rings half a turn forward, quarter back, (Repeat) might let you cut them in a bit deeper...

If that's not a goer then yes - some places will rethread if you ask them. Some specialist places might even have a 26 raleigh tool.

[stevegor]

Hi,

This might sound dumb, but, check that there's no powdercoated stopping the cups from threading right into place, if there is, don't waste time and effort trying to scrape it out, get a gas lighter and melt it.
If not, follow LP's instructions and you should have no worries, remember that the un72 bb is 3mm shorter than the R20's bb shell, 73mm and 76mm respectively, so the Phil cups will be recessed 1.5mm each side...give or take.

[gruffydd]

oK mates, there is no powder coat in the way, that I am sure of. But I am still working on this little problem. I checked today with a local frame builder and he does not recommend re-threading the bb shell. And so far I can't find some one with a 26 tpi bb tap. So I will let you know how I am going to proceed. I may well have to put a big lever to those cups and really reef 'em down.

[alecw35]

try screwing the cups in with out the cartridge in them.

might just need fitted properly.

use lots of oil...only good use of WD40..