It's been about a year since I started commuting, 10+ miles a day, 5 days a week, unless the weather is awful or I have a cold or something. I got an old Schwinn cruiser (Giant-made 1980 World Tourist) off of CL for $80, rebuilt and lubed it up, and have loved every minute of it. Put over 2000 miles on it. Alhough I haven't lost much weight, I've gained a LOT of muscle!

Recently, I've had a few (age or wear-related?) mechanical failures, one of which resulted in me bouncing and sliding on my knee and elbow to a stop from about 25 MPH. The bike uses a single chainring with a 5-speed rear freewheel, although there is a 6-speed on it right now, because the LBS couldn't get the old freewheel off. I bent the rim good when I had to choose between a lolheug pothole and running into a car that pulled out right in front of me. Stupid ancient SunTour thing. I'd keep the 6, but I have some good hills on my route, and I can't get to the lowest gear on the 6 without upgrading the shifter or derailer, or something.

Anyway, I am debating spending money on the old girl, because the frame isn't that great (1020 carbon-steel), and there are a lot of components that need replacing or repair. I'm definitely going to buy a new bike to be my main ride, but I'd like this bike to be a backup. The big issue, and the one that resulted in me bouncing on pavement in traffic, is that the chain likes to jump off of the chainring randomly. The chain is not bent or sticky, and the ring itself doesn't look too worn. I'm honestly wondering if the rear derailer is too old to keep tension and slips on bumps. Has anyone ever heard of something like this?

Finally, the bike I'm looking at is the Giant Via 2. The LBS is a Giant dealer, so they can get it in the lolheug size I need (they don't usually stock the XL, but will order it for me). Anyone have experience with this bike? Suggestions for alternatives?