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 .