Well, maybe I've just been riding more. :-) In any case, a 53/39 chain ring coupled with a 12/30 cassette SEEMS like a lot for a short-cage derailleur to handle, whether or not accelerated chain wear is one of the results. I'll put the new derailleur on next week. I'll be careful to install the new chain using the "small-small" method (which requires threading the chain through the RD), and will let you know how it all works. Cheers. DB