About 18 months ago I purchased a Trek 820 MTB for $50 for use as an about town bike from my office. Intent was to leave it locked up on campus, in an outdoor rack. The bike was well used, the previous owner, a woman, had used it in mountain bike races in Alaska. She left a $100+ Terry Fly Ti saddle on it, which I moved to my primary bike and loved it. So I considered the rest of the bike to be a freebie.
I did use it about 10 times last year. Then got away from it when our cold, icy winter swept in. I had it locked in a rack that was under a roof, but it was buried in snow drifts from time to time.
This Spring I admit that I never got around to cleaning it up. I walked past it on occasion to check to see if it was still there, but never even touched it until today. So it had been 8 months since I had even laid hands on it.
I found it dusty, dirty, rusty, and there were cobwebs on the frame. I felt bad when I saw that. So I cleaned it up, lubricated it, filled the tires, adjusted the brakes a little, and took it on a 4-5 mile spin. It ran well. But there's a lot more rust on it than when I got it ... some on the handlebars, several of the screws are badly rusted, the cables, and the chain. Cleaned that up some, but it needs more TLC. At least it doesn't look like it has been abandoned.
Don't know why I didn't get to it sooner. I walk past it every day to/from my parking lot.