I waited a bit too long to replace the chain on my commuter, and now both the chain and the cassette are shot. They're not so far gone that I can't ride on them until replacement parts arrive (i.e. no skipping, yet), but the chain-wear gauge does fall rather easily into the gap.
So...question: Do I need to replace my chainrings along with my freewheel? The bike is a double, but I use the big ring almost exclusively.