SR Royal Cranks

I have a set of vintage SR Royal track cranks (sort of fluted campy copy). I read these have an ISO 106mm spindle BB, Can anyone confirm this? If it’s the case I was planning to use a Miche 107mm BB.

If you read that, then I’d go with that. I’m sure you’ve tried a quick google search to confirm.

Just remember that spindle length is limited by chainstay clearance, so you need a spindle length that matches your crank (for straight chainline) and your frame.

no - one told me that till i built my first. very annoying.

If you are unsure of the exact spindle length you need, but have a rough idea after measuring with calipers/ruler, you can get BBs which don’t have a fixed cup, like below (quite sure I’ve seen them as square taper too). I.e both sides are adjustable cups and you can fine tune your chainline/frame clearance.

Having two adjustable cups isn’t a problem on english threaded BBs, as the pedalling direction tightens the cups against each other.