I broke both of my wrists last year pretty badly. I broke the left one in 8 places and the right one in 7places. I had em' both in external fixators with 4 pins in each and a plate in my left one. First off, you have to ensure that you have given the bones long enough time to heal. The younger you are the faster that will be. If you try to do things to quickly, you will be right back where you were when you first broke it, the doc can give you advice on the time period. It also depends on which bones you broke, the navicular and the other smaller bones in the center of you wrist take longer to heal due to the fact they recieve less blood flow than the ulnar and radius bones in your forearm. The biggest thing you'll have to overcome first is the atrophy that occurs in your muscles and tendons. It will feel like you can barely move it at first. You'll have to grit your teeth and move it anyway. I went to physical therapy for 3 months after the 2 months in the fixators. It seems like a long time but in the end it paid off. I can move my wrists with about 90% flexibility with only an occasional ache. Considering the first doctor to look at me didn't want to work on me and passed me on to another doc, it's pretty damn good. Buy a hand squeezer and a gyroscopic ball as well as some light weights. Do alot of reps of hand squeezing, wrist curls, and circular rotations with the gyroscopic ball before you go riding. Get the wrist strong before you jump on your bike again, otherwise it will hurt like hell when you do start riding again. Good luck, be patient and work hard. Don't fool around with this or it will become a life long problem. Do it right and you won't have a problem with it.
Pat