Using a chainwhip is not difficult. I think changing a cog is at least as easy as changing a chainring...
just my 2 cents...




In all seriousness, if you can find cheap chainrings in your BCD, I would swap chainrings. I haven't even done that much swapping, but just in theory I agree with a lot of the above, especially considering the difficulty and wear of swapping a cog vs. a chainring. You have to get that lockring off, and then the cog, which is probably quite sunk in there by now. You either need to use a chainwhip and all that jazz or get creative with the wheel mounted on the bike, versus spending a couple minutes with an allen wrench and a screwdriver.[/QUOTE]