My main worry about these machines is that they have very small wheels - and therefore are very sensitive to bumps and holes in the road. If they hit a bump at speed they could veer off to the side and it is in the lap of the Gods what happens to the rider

Also - the brakes on them are nowhere near what you would expect from an ebike - and the centre of gravity and ability of the rider to control their movement during sharp braking - are much lower than would normally be acceptable for a road vehicleWhich is why I am very dubious about their safety for use on the road - and the speed that they can get up to nowadays also makes them dangerous in places shared by pedestriansThere is a problem with new electric powered devices like e-scooters and hoverboards - and I am glad I am not the person who has to sort out what to do about it!!!