I have really old, more than 20 years old, 6 speed shimano 105 rear deraileur with 10T pulleys.
Nowadays the 105 rear deraileur started making noise and don't stop making noise even though I adjusted the rear deraileur.
I found that my chain has been quite stretched and my pulley has been worn. It seems like draileur itself is bent, but not sure about that.
So I'd like to replace both chain and pulleys, but I wonder if I can replace my 10T pulley for my 105 to 11T pulley for Shimano Ultegra. Since I really like my bike, I ride it a lot, and I really do care about it, I'd like to replace my pulley to a good one, not poor one, but I can't find a nice pair of pulley for 6-speed.
I'm not sure my old 105 would work with 11T pulley. If you ever tried this, please tell me if it worked or not. Thank you