I haven't touched anything on my bike. My old classic '85 Fuji is perfectly fine and just goes and goes and goes... I wrenched my back when I was hitting golf balls at the range, and stupidly tried to ignore it thinking it will go away on its own. Worse thing I did was continue physical things immediately after donating blood (I'm also one of the blood drive coordinators with Masonic Lodges), instead of waiting at least a week. Lesson learned!