So long story short, I'm basically over hauling my 2008 Giant Rincon and I'm having a blast doing it. Replacing nearly everything on it.....but I have some bottom bracket question.

The bottom bracket is a Modus sealed bearing cartridge bc-73, 68x113 (also says BC 1.37x24T...not sure what the hell that is..Threading type??). The front derailleur used a bottom bracket mount that was approximately 2.5mm thick.


1. Since I'm not using a front derailleur (switching to a 1x10 drivetrain) will I now need a 2.5mm spacer for the BB?

2. If I replace the BB with another cartridge unit do I need to get a 113mm length or different length.
2a. If I do need a different length how to I calculate it? Just add 2.5mm to it?

3. Could I replace the cartridge BB with an external BB?
3a. If so would it only require to BB shell to get chased and faced to do so?

4. The weld's where the BB meets the chain stays go all the way to the edge of the BB. Will this effect the ability to face the shell?

EDIT: here's a picture of the BB welds
BB Weld by gremlin75, on Flickr


Ok I think that's all the BB questions I have for now. Thank you all in advance.