I'm no gear head, so hope I didn't confuse more than help with my version of the technical answer. Sorry if I did. I do have bikes with a wide variety of wheel sizes, so I do know there are differences, but translating that into something others can understand isn't easy. Again, sorry for my clumsy attempt, everyone.

I stand by my answer of keeping your XS bike and working on your training, though, Kajero. From personal experience, I know it's much more the biker than the bike we ride. Best of luck, but no matter what you do, just keep riding.