Originally Posted by
cyccommute
Put a bicycle between his legs. He couldn't "plant" his foot to take a portion of the impact because there is a gear in the way.
No there isn't, because you deliberately separate from the bike. I've done it many times. And if you can't position one foot, you do the rest of it. It's not an all or nothing thing.
The bicycle also increase the mass of the system which will change the dynamics of the impact.
No it doesn't.
Also increase the speed the person being throw before the throw and see how quickly he can react to the impact with the ground.
The same amount of time regardless of bike velocity. My fastest wreck was on a motorcycle, about 65 mph, thrown over and above a van. Maybe a hundred feet, I'm not sure. This was before I learned any martial art and I'd had hundreds of off-road motorcycle crashes before then and figured I was pretty good at it, but I had learned a little in a couple of months of stunt-man fall training. I did a back-fall btw, bounced to my feet without a scratch and realized just how less effective "just falling" was.
How many crashes are "low slides".
The ones that actually hurt me, where not coincidentally I did go down with the bike like you suggest and didn't react quickly, flopping like a "rag doll" as you suggest.
Regarding your thought example, if your cannon shell is a cylinder and grazes your body, the only damage you'll see is due to the force of friction from the shell and your skin and clothes. If on the other hand the shell is conical, that's not like hitting the flat ground. That would be a rise in the ground in front of you, as I mentioned earlier.
It might not be worth someone's time for just bicycle crashes, but that's OP's question and I want to reassure anyone reading to disregard the deprecations. If you're skeptical about me - nothing intrinsically wrong with that - you can visit a dojo, find someone who also rides motorcycles or bicycles and *also* is an expert in falling techniques, and ask their story.