Is there a way to know what size of smallest chainring will be compatible with a given frame?

Question

I've been slowly changing a Devinci Milano I bought to be more like a touring bike than a hybrid. I've installed drop bars and sti shifters. Everything is working pretty well, except that I'd like to have a more road-oriented set of chainrings.

So I plan to swap in a standard road 52 - 39 crankset. Is there any way I can tell if it will fit? I realize it will take me five minutes to check, just wondering if there's a better way.

Answer 1

It depends not only on chainring size, but also in bottom-bracket spindle length, which may vary according to preference/taste/availability, respecting two constraints:

1. Far enough from the frame to avoid rubbing against the chainstay tube;
2. Close enough to the frame to allow for the front deraileur to pull the chain over the big ring.

This constraints are fairly flexible. Your frame is a hybrid one with a OEM chainring size of 48/38/28, so most probably a 53 big ring (only 5 teeth difference) would fit without problems.

All in all, there is no reliable way to anticipate if it will fit or not other than actually trying, which is relatively easy with the help of the Local Bike Shop.

Answer 2

The Devinci Milano uses a standard 68mm English threaded bottom bracket shell. This should be compatible with most road cranksets, so long as you replace the bottom bracket as well.