We had two of them (
MX350 and 650) and they became really popular with other kids in the neighborhood so we had a “gang” of four or five for a while. Even upgraded one with a 36V LIFeP04 battery, which doubled range and reduced weight. The controller will apparently handle 48V but that would have increased top speed. Then we donated it to a school, who used it to create an autonomous vehicle. Purchased on Amazon or maybe WalMart.
If you look around you can buy them used for $1-200, usually needing battery replacement. The batteries are just three 12V garden equipment batteries and can be purchased cheaply and it is simple to replace them. Be sure you get the charger. We also replaced freewheels, chains, motors, etc etc.
It might be my son’s favorite toy, ever. Bicycles and scooters are great but a powered bike gives them an additional sense of independence. The biggest problem we had was that pedestrians would tell them to get off the sidewalk and motorists to get on the sidewalk.
They were also used for towing, which could result in safety issues. Trailers included wheeled luggage, wagons, you name it.
Keep on top of the brakes, which are mechanical disks that need adjustment and pad replacement.
The kids were required to wear a BMX or skateboard helmet, safety glasses and gloves. No helmet and it got locked up for a few days: zero tolerance on that. We started with a full face dirt helmet, but had problems because the neighbors couldn’t see who was on them and would call the police (who repeatedly told them it was legal). The skateboard helmets seemed to work for the >20mph speeds.
BMX Helmets, Full-Face & Skate Style | Bell Helmets