Thanks all for the suggestions & links. The front sprocket was just
starting to hook (slightly concave on one side), so I replaced it with
the chain. The bike runs sooo much smoother now - it's like it's
young again.
I ended up getting a DID O-ring because that's all that I could find
locally and I didn't want to wait for mail-order. The dealer markup
was huge ($150 for a 130-link DID-O-ring). That impatience taught me
a lesson, though: order online next time - get what I want at a better
price.
