A Brief History of Shimano Compatibility by nalc / "Always gritty in Philly"
Mirror of https://old.reddit.com/r/Velo/comments/84z9p9/a_brief_history_of_shimano_compatibility/
I promised /u/thirty-five- that I would give him another writeup for the wiki, and I've got some time today so I figured why the hell not tackle drivetrain and derailleur compatibility?
As usual, the late great Sheldon Brown is a fantastic resource, but following his passing in 2008 it is rather hit or miss whether you can find compatibility information on newer stuff.
To start off with a disclaimer, this information is compiled from a variety of sources and while I believe it to be correct, there could be mistakes. Feel free to point them out and I will correct them.
To start off, we must explain how a derailleur works. At the simplest level, the point of the derailleur is to move the chain sideways at the point where it meshes with the chainrings or sprockets, forcing the chain onto the adjacent chainring or sprocket. In ye olde