I’m building up a Cotic Soul frame as a 10×1, running White Industries ENO cranks (170mm), with a 32T ring on the front, and a SRAM 10 speed cassette on the back, but when it comes to getting the right BB things get ‘slightly’ confusing for me…

The BB on the soul is listed as ’73mm’ and he guys at Cotic told me… “The Soul chainstays are designed to work with all the modern Shimano chainring combinations with a 50mm chainline” – I’ve know idea of the correct ‘QFactor’ either – so my main concern is to make sure the chainline achieves this ’50mm’ that Cotic state I guess, no? Or is there an optimum for a 10×1 set-up?

Basically I need to know how wide my axel needs to be I think (assuming it’s a JIS)?

Like I said at the start, confusing huh!

All help and advice gratefully received, thanks.

I’ve always just put the chainring on a set of triple cranks in the middle position and installed them as normal… two spaces on the drive side, one on the none drive side.

I wouldn’t listen to me though, I don’t actually know what a QFactor is…

113mm axle for the WI ENO cranks puts the chainring at 47.5mm from memory, so either live with that (should be fine really with 1×10, only an issue with non-WI SS hubs which don’t use 47.5mm) or use a longer axle to space the chainline out.

50mm – 47.5mm = 2.5mm = BB spindle needs to be 5mm longer (2.5mm on each side) = 118mm axle

Q-factor is a measure of how wide the cranks are, ie: how far apart horizontally the pedals are, conventional wisdom goes with narrower being better, some of us with funny knees get on better with wide Q-factor, don’t worry about it unless you know you have a specific requirement or you’re going to try and run a very narrow profile pair of cranks on a very short BB axle, in which case you have to look out for clearance problems.

Thanks Amedias, this is exactly what I needed explaining – much appreciated.