Originally Posted by Rob Glatfelter

Most people replying don't seem to actually be reading this, you however, are spot on, so thank you.
The bike I'll be putting this on has extended drops, but I'm not kidding myself about them being extended enough, 13 to 22 is a pretty big jump, I was planning on carrying 2 chains from the get-go, though from what you said, that MIGHT not actually be necessary, sweet.
I think I might go ahead and build a rear wheel with a BMX hub then, would make this a perfect setup and would only have to worry about space for one bike then. Fantastic.