Originally Posted by
FLYcrash
1x9 is pretty wide. Your chain's going to be at a pretty big angle in the extreme gears in any case, so it's pointless to lose sleep over chainline.
If you really want to be sure and aren't in a hurry to get the bike done, buy the wheels/cassette, install them in the frame, and measure the chainline (to the 5th cog) with a ruler or caliper. Then buy the BB/crankset with this figure in mind.
Theoretically, the choice of hub and cassette should unambiguously determine the chainline, but I haven't ever seen published chainline specs for a cluster before (to the extent that the concept is even meaningful).
Best of luck.
Not spec'd for a road chainline, but I run a 1X9 on an MTB set up for dirt/fire roads without problem. Crankset is a SS 32 with bashguard on the outside. Just for a little extra peace of mind I have an inexpensive Blakspire "stinger" chain keeper installed. There have been no wear or chain jumping problems.
The SS chainring is set up right on my 5th cog. If all else is equal this would be expected as it occupies the place that the middle ring would on a triple. I'm using an Isis drive 113mm bottom bracket so I expect that you might be able to use a similar crankset with a 108mm BB on a road frame.