Originally Posted by
wphamilton
I'm serious, I'm not "arguing" physics with people who haven't studied it. I take this off-topic "why do airplanes flare" as a question. The flare reduces airspeed by increasing the frontal aspect, and produces lift due to the angle. Neither of which have much to do with a bike crash.
I will give you a suggestion though. If you truly want to solve the ballistic motion and get an idea of impact, start with a vector diagram in terms of momentum.
Some of us
have studied physics. You are wrong in your assumptions.
Originally Posted by
wphamilton
You've seen videos of over-the-handlebars falls surely. Hit a curb at full speed, the bike is impeded but you still have momentum. If you're not clipped in and not holding on deliberately, you'll naturally separate from the bike. And frankly your first instinct should be to push off, not hold on.
The only thing that holding on does for you in over the bars is to help start your body rotating before the roll. You need to turn loose as soon as that happens or the timing is thrown off and you'll land flat, not rolling.
And your first instinct is wrong. Instinct also tells you that you should put your hands out to try to stop the fall and/or protect your head. That works well for our monkey brains and walking speed but our monkey brains fool us when we get faster than walking speed.
Additionally, you aren't going to "roll" all that far. If you let go of the bike, chances are that the bike is going to travel further than you and it will hit you, risking further injury. Holding onto the bike provides at least a
little crumple zone so that the body doesn't take the full brunt of the impact. If nothing else, hanging onto the bars keeps you from putting your hands out.