I'm building up my new Pegasus and have a bit of a problem with the crank clearance. The BB is a 73 x 113 Royce Ti (the frame's BB shell is 68mm but this just means the cups are a bit proud of the shell, no big deal). The problem appears to be with the 113mm axle. My Middleburn RS7 cranks install just fine, but once fitted there's only about 3mm clearance between the crank and the chainstay (and this is before tightening them up after a ride or two). I can actually flex the thing enough by hand to get the crank touching the chainstay.

Middleburn cranks are apparently designed to have a correct chainline with a 113mm axle, but it looks like I'm going to have to go with at least a 118mm axle on this frame. Any thoughts on whether this will screw up my chainline once the bike is all built up? Cheers.

It may be a compromise to get it to work and clear the chainstay.

Does the Royce not allow you to adjust chainline a bit?

How about tightening the cup in fully on the non-drive side & then using a 5mm spacer on the drive side?

Would that work?

I run a 118mm BB on my SS with Middleburn cranks. I just spaced the rear to get a good chainline. If the Pegasus will be SS then it should be fine.

well I can certainly offset the axle to one side or another, but the problem is that I only get 3mm clearance on both cranks..so I can either have 5mm clearance on one side & 1mm on the other or…you get the idea. Of course, the 118mm axle would give me more room to play around with adjusting the chainline, good point.

going 1×9 on the Pegasus to start, but will ultimately be fully geared probably next year.

I use a 118mm BB with rs8 cranks (coz my inbred had little clearance), but I am only running 22/34 so no big ring. If you don't feel the need for a triple then I'd do it.

If you do feel the need for a triple then…..errrr….might be ok but a little crap…but triples are crap 🙂