Technical Q&A with Lennard Zinn – Splines, cleats and big guys on bikes
Losing my gripDear Lennard,I am having a problem with the removal of the drive-side bottom bracketcup. It is a Shimano UN 72 and it has been removed so many times that thesplines are now gone. The bottom bracket itself works fine and I can leaveit in, but eventually it will need to be replaced. The splines are so rounded off that when pressure is applied in an attemptto remove the cup, the bottom bracket tool spins and further chews up thesplines. I am turning the tool clockwise for removal.Jeff Dear Jeff,The first thing to try would be to get your hands on a Tacx BB cupremover, since it