Originally Posted by
ebgbz
what is " i'm not sure that I have a 26tpi threaded bb. all i know is that the trial old RPM7420 threaded in very smoothly without ANY binding. if the RPM unit is a 26tpi unit then i presume that by threading it in to the shell easily MIGHT indicate that the threads match. Is that valid ?
If the newer bb threaded in easily you are fine and, one way or the other, the threads match. Typically an English bb cup will thread into a Raleigh bb shell a couple of turns and then get obviously too tight so it doesn't take much to find out they are a mis-match.