Sterling BB conundrum

[Mark]

Hi Folks,

I've just purchased a Sterling frameset and am excitedly beginning my build. I plan to run it with a Middleburn Uno chainset (sq taper) but need to confirm the correct BB spindle length.

The Uno gives a 50mm chainline with a 113mm BB so am I right in thinking that in order to get 54mm I will require a 121mm BB?

Has anyone any experience using Middleburns on Rohloff equipped Thorns?

[Mark]

I just had a play with this in the end as after much tinkering with vernier calipers it appears UN54 BBs aren't symmetrical, i.e. driveside square taper length doesn't necessarily increase linearly with spindle length.

Anyway in case anyone else fancies running the same Uno setup, a 73 x 118mm UN54 gave me a great chainline.