Hi. I'm in the process of changing to 1×9 just now and bought an XCX as chainguide. I'm running Middleburn RS7 cranks with their CD spider and a 36T ring, but even with an e-type BB the chainline is totally out (it's actually 50mm like normal, it's the guide that seems to require a 47/48mm chainline).
After having a little measure, it seems that the chainring sits about 3mm too far to the outside (it's mounted in the middle position and just touches the guard as it spins with no chain fitted). Because it's to the outside there's no way to use the BB spacers. So (finally) I was wondering if it's fine just to stick some washers between the spider and chainring to push it inboard about 3mm? I have some old longer steel chainring bolts I'd use. I figure this would bump my chainline down from 50mm to 47mm, would this cause any problems with the gears?
I guess the other option is to push the plastic guard of the XCX out 3mm from the plate, but that would involve a fair bit of filing a shaving I think.
Any thoughts? Thanks in advance.
Starting to wish I'd paid the extra £5 and bought a Paul's.