Ah, memories... of extremely questionable childhood engineering

Obviously, this photo is staged. My baby sister couldn't even reach the pedals!

I (pictured in lawn chair) was the one who crammed myself onto the tricycle, to cart around my baby sister and little brother (not pictured, taking the photo).

I have no idea what the inflatable intertube was for. Possibly as a yoke if I needed my brother's help getting up a hill.

Speaking of hills, at the bottom of the hill behind us, lived my neighborhood enemies: two boys about my age who enjoyed shooting bb guns at cats. We didn't have a cat at the time, I just objected on principle. With my fists. Okay, it was more like flailing shoving matches.

Anyone else have stories of questionable engineering their parents did nothing about?