Originally Posted by Portis
I've got an old derailleur laying in the garage, where the teeth look like the one on the right. It started to shift like crap. I guess my question is......when you know you have a part that might be suspect and start causing trouble, why leave it on there?
Maybe if you didnt ride every day year round like me, but I like to keep stuff replaced. I'd rather ride than have failures.
A worn derailleur pulley isn't going to break anything else and isn't a threat to life and limb. It'll just continue to wear until it doesn't work very well any more. A worn chain, on the other hand, will wear everything it touches until you have to replace it all together. Worn rims and brake pads or corroded and frayed brake cables can all be very dangerous.
So, if derailleur pulleys are getting worn but they still shift OK, there isn't a pressing need to change them. You might want to reconsider that if you're leaving on a long tour, though.