I need to replace my bottom bracket cartridge because it is knackered. After a bit of reading it seems that there may be many types of cartridge variations (axle lengths, threads, size of square taper, etc etc). So I'm not sure how to fully specify the required replacement so I can be certain it will fit (other than buying the exact same part).
The old part is marked as a Stronglight JP400 122mm. Chainset is shimano. Bottom bracket shell width is about 69mm (as near as I can measure it). Frame is aluminium.