jtolleson said:If you need to use shorter than a 9cm stem on the XL (preferably not shorter than a 10) then size up. If you have to use longer than a 12 stem on the L, then size down.
It's kind of a generalization, but it is likely what I would do. But if you can ride the L with an 11cm stem, for example, or the XL with a 10cm stem and get a similar reach, then I'd probably go with the smaller frame.
Caveat: I don't know how the headtube lengths compare on each. Will your bars be lower than you'd like on the L?
brianmcg said:I think you explained it backwards.