I've sold several bikes in the past, but there's only two that I've regretted selling, a 2005 Colnago MIX and a 2007 Redline Conquest Pro, sold both bikes when I got laid off last year (only 2 of 4 bikes I sold during this time period), I've since replaced them with other bikes now that I'm working again but those two put the old saying "you don't know what you've got till it's gone" to use. What have you sold that you regret?