How do I move my chainring without moving my crank arm?

Question

I recently did a 1x10 conversion on my mountain bike. I replaced almost everything on my drive train except for my crankset. The single chainring (104 BCD, 34T) fits onto my drive-side crank arm in the position where the large chainring used to fit (used to be 3-speed in the front). This causes some severe cross-chaining (if it's even called that on a 1x) when my chain is on the biggest cassette ring.

How do I move my chainring closer to the bike frame and therefore more to the center of the cassette? Can I buy spacers? Do I need to move my drive-side crank arm itself? Do I need to replace the crankset entirely?

Answer 1

If your bike was previously set up with three chainrings, then the new single ring should be placed in the middle chainring location (i.e., on the inside of the four mounting points of the crank). Assuming that this is a somewhat ordinary mountain bike, the previous middle chainring was likely a 32t, so the new 34t single ring should fit with sufficient clearance between the ring and the chainstay. This should substantially reduce your cross-chaining issues, although it is worth noting that a 1x setup will never have as straight of a chainline in either the lowest or highest gears as a properly used 3x setup.