I picked up a Raleigh Twenty a year or so ago, it was a bit rough, so I gave it a quick strip and repaint but the 3 speed hub was not working too well and the rims were quite rusty so a couple of days ago I thought I'd see if I could update it a bit instead. I got wheels & deraileur from a kids 6 speed mountain bike for nothing, but the wheels being smaller than the Raleigh items required looong drop brakes or a drop bracket. I had an old BSO mountain bike frame in the garage so I cut off the V brake bosses and welded them onto the Twenty. I also had to re space the rear dropouts. I need to tidy the welds a bit, my mask was playing up. (Thats my excuse anyway!) I wanted to use a modern cotterless bottom bracket but the Raleigh shell on a Twenty is about 76mm and has the Raleigh thread. I searched the internet for solutions and after reading many peoples work arounds I came up with my own take on what others had done. After a lot of measuring I decided on a 113mm theadless BB 68mm shell which I ordered from Ebay and when it arrived I took the grinder to the BB shell. I also needed to take a die grinder to the inside of the BB shell as the areas where the down tube and seat stays had been welded had 'grown' inside and the new BB was a snug fit. Lots of trial fitting and judicious adjustment with the grinders and it seems OK. Try on some chainrings. Chainline looks reasonable. Another thing that I wanted to do was to replace the plastic bush at the top of the head tube with a bearing, lots of fiddling about with bits out of the spares box and I came up with what I hope will be a good solution. I quite wanted to keep the steering binder, so again after measuring I cut about 5mm off the top of the headtube and fitted a top race. The top bearing cup was threaded internally but the steerer tube thread didn't extend down far enough to load the bearings so I ground out the thread and the bearings are adjusted as before the mod by the nuts above the binder. I'll finish mocking it up then stip it again for paint.