>>1213576If it shifts all gears, it's possible you only have to play with the barrel adjustment on the RD because it's too tight or too loose. Does it misshift from time to time (as in you go up and stays down and go down and it stays up?). The "roaring" anyway is usually the stuttering of the RD due to cable tension or adjustment being off.
The only noise a BB does is a grinding sound and you can tell when you push. If the BB was so fucked up that it actually causes the chain to jerk around, then you need to service it immediately.
