Which size BB cartridge?

[neilakee]

Hi
I’m going to replace my cartridge BB on my urban commuter, probably with a shimano UN-55. Not sure what size to go for.
I’ve taken the old one out, it’s 68mm 116mm (see photo). This size (116mm) isn’t an option, it’s either 115mm or 118mm. I’m thinking I go 115mm. Is this correct?
Thanks in advance.
Neil.

 

[Ajax Bay]

115mm will be fine; either would be. Miniml effect on chainline. UN-55 best choice.

 

[neilakee]

Ace. Thanks very much for your reply.