I had another broken spoke this morning - the third. This pulled the rear wheel completely out of true and I ended up walking back. Replacing the spoke is no big deal but I made me wonder what life there is in the wheels. I'm concerned about the sidewalls which are abraded by the brakes. I've done 11,000 mile on the wheels (Shimano 105) and a lot of it has been commuting along the A5 in grotty conditions.