Hmm, I've had a similar conversation with my doc but regarding a completely different issue (crohn's disease complications that we really don't know if they're exacerbated by me biking or not). I basically told him that he was going to have to figure out how to manage it without me giving up biking. And that I was completely ready to accept any consequences from my "hard headedness", as he put it. It wasn't a matter of switching bikes, but stopping altogether. So I understand your frustration. It's never easy to hear that you need to stop doing something you absolutely love. Maggie gave some great tips and advice. Maybe you can do some mods and help the ol' back out a bit. And I don't know if a dislocated rib is as painful as a dislocated knee cap, but you gave me some flashbacks. Ouch!

Good luck!