Well, my worst fear yesterday happened.. I had Sonya's bike up on a bike jack and both rims off getting new Whitewalls put on them... The bike was strapped down etc. When I went to put them back on Yesterday, I had already installed the front and was in the process of installing the rear. Well, the bike was close enough to one side of the jack from being shifted around etc that it slid off sideways. Luckily I was there to catch its fall..... Needless to say, I am sore as ****** after wrestling that thing back to a safe position.. ( which was not back onto the jack but sitting on the exhaust on the floor upright, couldnt get it back onto the jack alone.... ) Had to jack it back up from the swing arm and used lots of boards under bike to eventually get it high enough.. ( used 3 jacks including the bike jack.. Well, after that experience, I know that if I ever go to pull the rims from a bike, I will not do it on the jack, I will have a wheel in a wheel vice and do 1 at a time..... My already jacked up Knee cant take much more when it comes to bikes landing on it. Oh, and the bike came out with one little scratch on the rear fender ..........