Let's hear the horror stories! My worst was a Wally World bike my wife and I inherited from a friend. The bike was a "Mountain Bike" style fully rigid and about one size too large for me. When I sat on the bike the front fork visibly flexed outward as if it was going to snap off (I weighed 140lbs at the time). I rode down a small downhill, not wanting to go fast for fear of structural failure. I applied the brakes (which I had just adjusted) and after a breif moment of funtion they gave up entirely. I luckily coasted to a stop and looked at the brakes. The calipers were made of flat stamped metal and when I had applied the brakes the calipers simply bent. Shifters were down tube but would not hold a gear and continually shifted back to the lowest tension gear available. Got off the bike and threw it in the garbage.
Who else has a bike horror story?