Thanks for the great advice everyone. Took the bike into a LBS on my way home tonight and the mechanic gave me a few options. He could replace the broken link with a master link and see if it rode okay or replace the chain and freewheel. He said he would recommend just replacing the link (~10 bucks including labor) and seeing if the chain skipped. If it did, then it means I'm stuck replacing all the big stuff.

Haven't had a chance to really ride it out and test it yet, but fingers crossed. Also, while I was in the shop I asked him how much a tune-up costs. I was told 83 dollars!!!

Anyways, for 83 dollars a tune-up is not worth it to me. So a quick question about adjusting my rear derailleurs. I've read the instructions from Sheldon and the written instructions on Bicycle Tutor and just had a question.

Right now, the chain falls off at the highest gear (smallest cog) and will only shift as high as the third cog when I really jam the shifter all the way back. It is a six speed rear cog. Because it is so far off (3 gears away) do I have to tighten the cable or can I get away with just adjusting the limit screws? Adjusting the limit screws seems easy to me, messing with the cable much more difficult. Thanks!