At its highest level Motocross is dominated by naturally aspirated 450 cc single cylinder four strokes from Honda and KTM producing around 55 bhp. Stark Future is in January 2023 launching an electric rival that outputs as much as 80 bhp and has a duration of 35 minutes in race mode - much longer if operated in trials riding mode. Moreover, this bike offers direct drive and the full torque range is always available to the rider.
In this (off road) world the energy requirement is significantly less than in a (tarmac) MotoGP event of comparable duration. That is why it is feasible to provide sufficient energy storage for a motocross bike that on paper is more competitive than its ICE equivalent. At the same time the electric motor has a low duty cycle consequently can be smaller than would be required for road racing.
The Stark VARG’s battery is lithium ion having 400 cells and maximum voltage of 420 V and nominal of 360 V and with an energy capacity of just over 6 kWh. It is packaged in a magnesium case and is air cooled. Its structure is partly stressed helping lighten the chassis.
The motor and the inverter are both liquid cooled using a water-glycol mix. The motor has a 7075 aluminium case incorporating the necessary water jacket. The three-phase motor has a permanent magnet rotor that is carbon fibre sleeved to allow high rpm. The motor runs up to 8000 rpm and a single speed reduction gearing plus a chain drive turn the rear wheel appropriately.
The rider can choose from different operating modes covering the likes of power curve, throttle response and engine braking with even a virtual flywheel effect available. More information will be given in RET 145 (February/ March 2023).
