should be 51,4 (usually sold as 51mm)Thanks. If I replace it with another square tapered unit.. I’m just wondering what I need to look for?
Is it US bottom bracket 51mm?
Measure to ensure.
You may not need to replace the cups, but its always a good idea. If the bearing sizes are the same in the new unit you'd be fine to keep them though. If you don't want to have to get the hammer out
The BSA threaded adapter is also a good route.
What make is the bike?