I've had one honest low-speed tipover. It was with my Kawasaki Concours - nearly 700 lbs with a full 7.5 gal fuel tank - talk about top heavy. I was trying to get around a friend's car in his driveway, drove up onto the lawn and lost momentum, and was too far off the ground to get a foot down. When it came to rest, it was lying past horizontal, and there was not a chance of budging it - in fact I may have been stuck under it. I had to get my friend help me to lift it back vertical. I'm 6'3" and 210 lbs, so it can happen to anyone of any size. If you're smaller and thus, weaker, I can see where this could happen more easily. Even on a much smaller, lighter, shorter (seat height) bike, I can imagine a situation that could result in me dropping it.