Originally Posted by
Thisguy
So I am really a noob when it comes to bike mechanics, especially when it comes to index /friction shifters and derailleurs. Are there specific index and friction derailleurs? Can someone replace index shifters with friction ones and keep the same derailleurs? How can you tell if a uninstalled derailleur is index or friction?
Modern derailleurs are almost all designed for indexed shifting. Derailleurs from the late 80s or earlier may not be. To work properly without modification or adapters, indexed shifters must be mated to a compatible derailleur and a cassette or freewheel with the right number of speeds.
For Shimano, almost all index compatible derailleurs work with almost all indexed shifters. With Campagnolo I believe the derailleurs are made to match a specific number of speeds and the appropriate shifter. Sram MTB rear derailleurs must be used with Sram MTB shifters, but the front mtb derailleurs will work with shimano shifters.
THere are more exceptions and notable points but I am too lazy to continue.