The HUSQVARNA automatic gearbox
HUSQVARNA 420 AIC/AE Automatic, 1982
It is not a well-known fact, but between 1976 and 1988, HUSQVARNA produced and marketed off-road motorcycles with automatic gearboxes.
The system used, which remained more or less unchanged during the period in which it was produced, consists of a centrifugal clutch connected to a series of secondary clutches that engage sequentially to shift to the upper (initially, 4-speed) gears.
When the accelerator is cut until it is closed, the motorcycle goes into freewheel, when accelerating again, the gearbox engages again in a ratio according to the speed of the rear wheel.
The system was very simple, efficient and reliable.
The great advantage is, especially for less experienced pilots, not having to pass the box to overcome obstacles, together with the fact that there is no risk of the engine shutting down in a more delicate situation. The big disadvantage is that the bike is freewheeling when you close the throttle, and this feature can be really scary when descending, for example, a firebreak!
In any case, the series-produced motorcycles were sold in reasonable quantities, although their production ended in 1988 with the liquid-cooled 430cc and, in this model, only 3 speeds.
The latest automatic version
The ease of learning and use led Hagglund & Sons (an engineering company that, among other activities, designed military equipment) to have designed, under the initial designation of XM-74, and HUSQVARNA to have produced about 3,000 units of a model with this technology for the Swedish army, a 250cc 2T with the final designation of MC-258-MT, this version also had the particularity of having two retractable side skis to facilitate use in the snow.
The military model in action in the snow!