Well, I'm pretty new to the rollers. When I lose control, most of the time my front wheel will go off the side of the rollers and as long as I'm not clipped in or I can get clipped out fast enough I usually catch myself with my feet. But I do have th roller set up next to a wall and on the other side is a chair or bench because I need a boost to get up on my bike, the rollers sit my bike up like 3 inches. So I can catch myself with the wall or the chair also. I've never went over, except only when I was sitting at a stand still and I leaned forward and put to much weight on my handle bars, but once I get going, I've never had that problem. If you go onto Youtube and look up "bicycle roller" there are some pretty good videos to watch and I don't mean educational, hilarious!!!