when I was a kid in Belgium I dropped my front wheel down a grate that was replaced in the wrong direction. the wheel instantly dropped and stopped, I flipped over the handle bars, landing on my back. We had sreetcar rails everywhere and another hazard, cobblestones. slippery when wet, and so much vibration they would numb your hands.
No rides for me lately, below freezing and snowstorms lately. Warmer but raining today. It will be another month or two before it is fit to ride again up here in the great white north.
Steve