ALL of them? As in every single one that they've ever made?
Wow.
Apparently the problem is the way they behave when max speed is achieved.
The thing is, hitting max speed on a self balancer physically means it can no longer balance itself. Balancing out a lean by the user, IS to accelerate. Simply maintaining speed is not enough, to keep a user that is tilted over, on-board, acceleration has to be occurring to offset gravity. If there is no more speed, then that also means there is no more acceleration. If the user is still leaning by this point, gravity wins.
EUCs solve this problem by keeping their electrical actual top speed far above the advertised top speed, and signaling to the user in some way when they ABSOLUTELY MUST STOP accelerating. Because once the hard limit of the voltage coming out of the battery is reached, the self balancing ceases.
OneWheels have pretty small batteries, and much lower top speeds than most EUCs. I'm not surprised a lot of people pushed the limits, and hit them. AFAIK, they don't have an audible signal that warns the user they are approaching max speed, either.
Couldn't they just put like a small wheel on the front that only got used if they dip too far that way it's not a slingshot. Like it's still "one" wheel when it's used normally.
That still leaves the problem that when it hits top speed, the user is leaning forwards.
When the acceleration stops, the physical effect is the same as when you are leaning at that same angle, but standing still. That the board would be able to continue rolling at that same speed, doesn't solve the fact that to get under a leaning rider and to keep them fom hitting the pavement, it needs to accelerate, not just maintain speed.
Going from top acceleration, to no acceleration, is the same as going from no acceleration, to full braking, front wheel or not.
This is how all self-balancers work, once you hit max voltage, further acceleration, which is necessary for the automatic balancing to work, is no longer possible. Once you are pulling the voltage that the battery is at, that's it, there's no going faster, meaning the second you hit max speed, the self-balancing is also gone.
OneWheels being particularly weak performance-wise probably makes them worse than most, tho. Most self-balancers have plenty of extra speed to spare above their advertised top speed.
Unfortunate, but I kinda saw this coming when I first saw them advertised. Given the speeds, I feel at least a more “normal” electric skateboard is warranted, if not a standup scooter or bike.