Originally Posted by
chaadster
I'd tend to agree with your wife, if only because the moveable front wheel would tend to let the child/weight naturally move towards the ground, possibly smacking a kid face first on the ground, with the bike's and your trailing weight coming to bear on top.
Like you, I have no idea if that is actually how it happens, and certainly the nature of the accident would be a huge factor. One thing for sure, though, is that a weighted steering mechanism is inherently less stable, and I've never seen a bike crash where the front wheel stayed straight (i.e. inline with the frame).
The biggest issue for me is the height of the fall in any situation. With the mamachari, the kid's head is 4 or 5 feet off the ground; that's lot's of space to accelerate the tender noggin into the tarmac. It's a serious impact. With a trailer, for example, the child's head is probably less than half the distance, not to mention less likely to tip in the first place. Most also have some type of frame to protect the child in the extreme case of a flip.
So yeah, I agree the outcome of a crash with front seating and a crash with rear seating would probably be equally devastating.
My baby seat (see pic in post #4) is molded in such a way that the seat itself would hopefully absorb most of the impact in the event of a sideways fall. Hopefully his helmet would protect his little noggin. I also added another strap around his waist that I pilfered from his toboggan to make it a 5-point instead of a 3-point harness. Of course, I try to be proactive and avoid falls by riding at moderate speeds and avoiding busy streets.