I separated my cartlidge from my floating rib when I wrestled my freshman year. I was going crazy bridging out of a pin. My torso turned too violently, and separated it. I had to take a week off because of the pain. When I twisted to the left, it felt like some one was hamering a nail into the area.
Took at good 4 months for the pain to totally go away. Mostly because I kept working out, lifting, etc on it. The doctor gave me 500mg Naproxen, but besides being an anti-inflmatory, I stoped taking it after a few weeks.
Riding on it depends what it means to you. If you have two months left in your season, then take a week off. If you got a few weeks left, go ride. What isn't gonna stop you from hurting again if you did take a few weeks off.
Remenber to take deep breaths, this contributed to me getting a case of pneumonia with it.