Ninebot = Buynot
From the start my G65 MAX didn't perform up to expectations (having less grunt than the Beam scooters even in sport mode, and hardly moving at all in the default Eco mode), and the provided C5 cord was
defective. Then the rear tyre kept going flat, which turned out to be a faulty valve (I found a bit of fluff in a split in the rubber, apparently from the factory); worst of all, the spare valve Ninebot sells doesn't fit the wheel, and they don't provide the correct type either
So I've lost the morale to continue trying to fix it, and will look at other brands once our old house sells.
I can only guess the Beam scooters perform better because Beam actually hold Segway-Ninebot to their specification, unlike these retail models