A direct drive transmission system suitable for use with scooters, go-carts or motorcycles is disclosed. The transmission system comprises a drive shaft coupled to a motor shaft and a friction element which is guided longitudinally on said drive shaft, rotating with the rotation of the drive shaft. The system further comprises a roll bearing fixedly attached around at least part of the periphery of its inner ring to an end of the friction element and a stopper which is fixedly attached to the outer ring of said roll bearing. The stopper is adapted to affix a wire, which when pulled, moves longitudinally said friction element towards the inner end of the drive shaft so as to allow engagement of said friction element onto a traction surface of the drive wheel.