Silly me. Of coure, if swap the 42 for a 46, you get a higher gear, not a lower one.

If you add or substract 4 total teeth to the chainring & cog, you end up with the same chain tension. So if 42/14 works, so should 42/18, 38/14, 46/14, 44/16, (which is a perfect around town gear that great man like... me use), 45/13 etc.

Of course, if you try 38/14, you will have to take one link out of the chain.

This method seems to work, esp. if you don't do huge changes. Of course, if you replaced your 42 ring with a 54, then the chain would have to travel at a greater angle along the chainstay, so the chain would probably be too tight for your chainstay length.


(Using a half link, you could make a million more gear combos work: 44/14, 42/16, and so on)