Tandem Cycling - Tandem read BB question

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA

View Full Version : Tandem read BB question

jacobpriest
04-16-07, 11:46 AM
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. :D

EDIT: sorry for the messed up title.

mrfish
04-16-07, 12:23 PM
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.

See wikipedia (http://en.wikipedia.org/wiki/Bottom_bracket)

sheldon brown (sheldonbrown.com/bbsize.html)
zonatandem
04-16-07, 07:22 PM
The Roland is a China-built tandem and suggest your local dealer, where you bought it should be able to to asisst you. Believe the importer was in TX also.

TandemGeek
04-16-07, 07:44 PM
Given the pedigree it would be unusual for it to be anything other than a 68mm English/ISO bottom bracket.