I understand the reason why I would have to change - just trying to make sure it is always the case with these specific gear rings. I'm still getting conflicting reports. One shop agrees with you (and I suspect you are both right), but a friend says he talked to another repairman who says it may not be necessary. Since this particular repairman is arguably the best around, that is worth noting. When I get a chance, I hope to take my bike for him to see for sure.

My suspicion is that my friend either didn't pass on accurate info about my bike to him or he misunderstood what he was told! So while I wait for a chance to go there myself, I thought I'd do some basic checking with people here.

Thanks.