Charles et group:
Since I have owned very few bikes, that's an easy one. Both of the only two that I sold or traded away. First was a 1962 Cilo, all campy (gran sport), finger-tips, sew-ups, etc. with the loveliest paintjob (candy-apple red and blended cream) with superb Swiss pin-striping that I sold to my older brother. He rode it to Long Beach State where it was stolen, promptly. Darn thing is that my brother would have been just as satisfied riding, and not bothering to lock, a JC Higgins. In all charity, it was my lapse to let him have it.
Next, I traded my 1960 Olmo track bike, fixed gear, no brakes, to Jones Bike Shop (LB) - for a 1972 gruppo that I used to upgrade my 1963 Tornado. It probably was a good economic deal (please don't rush to tell me otherwise), but now covered with the wax of nostalgia, not to mention a contemporary appreciation of modern collectible values, I deeply regret trading Old Mo.
JB Froke, Pebble Beach CA