Originally Posted by
alexw
Thanks! I'll take a good look at them tomorrow. I'll have to google jockey wheels, but my guess is they are the part the chain runs on. Would those have been made out of plastic in some models? If so, that seems pretty weak.
I've got several bikes with Simplex and agree the retrofriction shifters are very nice. Jockey wheels wear out over time because of chain use. One of my bikes had a broken jockey wheel in the top position and I used a wheel from an old Shimano Tourney for the bottom guide wheel and moved the good Simplex up to the top position. These derailleurs, while cleaned up now, have worked flawlessy for a lot of miles.