Check out the next generation electric dirt bike for kids, the TAKANI TK1210-20.

This model comes with numerous upgrades compared to previous generations:

Peak power output: 2000W
Voltage: 54Vmax (48Vnom)
Motor: brushless DC motor
Torque: 10-35Nm (adjustable)
Battery: 48V LiFePo4
Battery Capacity: 18Ah
Seat height: standard 620mm (suitable for body heights from 115cm at parent's discretion, lower or increase the seat height with optional accessories )
Speed: 8 - 45km/h (adjustable, max speed also depending on rider weight)
Range: approx. 26km
Runtime: approx. 60 minutes
Charge time: 3h (reach 80% after 2 hours)
Weight: 43kg
Max rider weight: 65kg
Charger: 54.6V - 7A
Transmission: fully automatic with chain drive
Front suspension: hydraulic 'upside-down' fork
Rear suspension: adjustable mono shock with air cushion
Tire front: 2.75-12”
Tire rear: 3.00-10”
Brake system: hydraulic 4 piston callipers with heat dissipation liners
Brake safety: electronic motor shut-off
Chain and sprockets: 219H 10T/76T
Ground Clearance: 260mm
Wheelbase: 1010mm
Dimensions: 1470 x 640 x 870mm