I know it is super boring, but can you ride a trainer? Spinervals can be your friend.

I did not break my clavicle, but I broke my scapula in January and was able to ride the trainer with a sling (once it wasn't painful to have the jarring from pedal movement).

I used this brace http://www.push-brace.com/Products/S...1/Default.aspx at Wahine's suggestion. It locked the arm against the waist - yet when my strength was better and pain was less, I was able to free my forearm to allow better stabilization while standing on the trainer. It's a very versatile brace.

The trainer isn't great - but I sure wish I had done more of it, as I would now be in better shape than I am now.

ETA: My dogs are pretty smart...