BB measurement question

[420mTrax]

I've acquired a peugeot Aravis and intend to renovate the frame (531 pro) and put all the parts from my existing Peuogeot Etoile )HLE) onto it. IE, it's a frame upgrade.
The BB on the Aravis is 115mm. The BB on the Etoile is 122mm
Does that mean the crankset on the Etoile (122mm) sits more widely than the Aravis (115mm)?
So should I use a BB on the Aravis that works with my existing rear wheel and cassette?
In other words, the Aravis 115m BB wouldn't work with my existing drive train>

 

[hamster]

Always use the BB for the chainset.

 

[non-fixie]

It's easy enough to check how your cranks sit on the Aravis spindle, and what it does to your chainline.

Agree with Hamster that you'll probably end up with swapping BB's. Since you'll need to service it anyway, it's not a big deal.

Nice find, BTW.