Very true. If you've never been able to cruise on a skateboard, you might not realize how much damage an unexpected pebble or sidewalk crack will do.
Riding is a constant balance of scanning the pavement for inconsistencies and making corrections to mitigate them. I don't know if that's even possible at 20+ mph.
Your latter point is why I'm not really sold on electric longboards. Your control authority on a longboard is pretty low, and you need a lot of control authority to react to surprise obstacles/maintain stability after encountering one. Sure, DH longboarders exceed 25mph regularly, but they ride in semi-controlled environments (scout the descent for gravel etc before hitting it) and are exceptionally skilled.
Putting random noobs on electric longboards is a recipe for road rash and broken bones. A few years ago, three people in my office got Boosted boards, and I believe we saw two instances of pretty bad road rash and a broken bone among them.
The danger is in the perception. It took me about 10 hours of dedicated practice (over a few weeks) before I felt comfortable using a longboard as a transportation device off of public roads - eg: on a closed campus. When I have seen people pickup an electric longboard they feel safe in a half hour, but obviously don't have any reflexes to back that up.
I rode a Boosted Board for the best part of 1 year on the streets of Brooklyn. I ended up selling it; although I absolutely loved the experience, I knew one day I would rip my face off if I encountered even a small pothole.
Practically speaking yes, but this isn't an unsolvable problem. I ride Originals spring trucks, which use a cam and a spring instead of the urethane bushing in most skate trucks. It takes effort to keep them steady at speed for sure, but paired with soft wheels they feel like pure telepathy in terms of control authority.
> Electronic skateboards have bigger wheels then skateboard-cruiser which has bugger wheels then skateboard.
i've powered a regular street deck with hard poly wheels, what you said is by no means any kind of guarantee. Lots of hacked together monstrosities out there.
Larger and softer wheels work great for mitigating pebbles, sticks, bumps or cracks. I roll over some pretty gnarly terrain with 60mm 78a wheels. You could even to an extent at certain speeds roll of the sidewalk entirely and roll back on quickly and not eat it with these wheels.
It is totally possible. Generally on a One Wheel if it's a small pebble or sidewalk crack you roll over it. If it's bigger and you jump while going over it normally the board will hit the crack or whatever and bounce up into your feet. I was going down a hill near top speed on a one wheel when I saw part of the pavement was cut out, maybe a 2-3 inch groove. Did this, road through the intersection to the otherside and then sat on the curb until I stopped shaking. Probably the closest I've ever been to dying on a One Wheel.
When I went to university, I was going there in rollers, there was a nice slope where I could go relatively fast, in the morning, almost no traffic, good visibility, relatively smooth surface. All it took was a small peeble to launch me a few meters (tens?) flying away. The fall was much more impressive than the damage, I consider myself lucky and was basically the last time I used them. I realized how dangerous it was in comparison to just biking.
They're more stable than you think. I've ridden an eboard for around 1500km this year, and although I've taken some hard crashes (always wear protection, I lost the skin on my hands once and never again) they have been down to me overestimating my grip or underestimating the obstacle. Every time I've hit a rock I've just gone over it.
A lot of it is also the different, more forward leaning, stance you assume on an eboard.
Riding is a constant balance of scanning the pavement for inconsistencies and making corrections to mitigate them. I don't know if that's even possible at 20+ mph.