Hey guys and gals!
I am currently restoring a 80s or early 90s Roland steel tandem. The rear BB was completely totalled. It was pretty unbelievable how bad of shape the cups and spindle were. I tried searching the forum and I myself can't quite get an accurate measurement on the shell. I think its a 68 mm but does anyone know for sure if its 70 or 68? I know the spindle is about 127. Any help would be amazing! This is the last thing left to fix on it. I can't wait to have this thing up and running and take all the cute girls on campus out on it.
You should buy yourself some calipers to answer the 68/70mm question. Maplin in the UK do a nice digital set for £20, which you will use many times.
I am not an expert on vintage bottom bracket threading, but if your tandem is from 1980s, the only choice should be English / Italian threading. The major difference is that both Italian cups have conventional threads. For English cups the right hand cup thread is reversed to avoid coming loose while pedalling.