Originally Posted by BabyCowHK

Sorry that I didn't go through the whole thread, so what's your crankset? It should work just fine if you have the hollow shaft type crankset with a BSA 24 BB. Taper crankset is a no go. It will cause small chainring & big sprocket combo to scratch the rear fork above the fork pivot area. The chain line is too narrow.

This hollow shaft crankset can be directly converted to use a double chainring. The only requirement is to make sure that there is a 2.5mm spacer on the drive side or both sides to balance out the Q factor. And of course the rest of the FD mount and FD itself.

Some crazy mechanics I have seen installed two 2.5mm spacers on the drive side which kind of shifted the chain line too much. Don't make that mistake.