a three - wheel motorcycle having an outer frame with rear wheels mounted on a double axle with differential therebetween for a drive from a powerful automobile type engine together with an inner support frame pivotally mounted from said main outer frame with said inner pivotal frame supporting the front motorcycle type single steerable wheel . handlebars mounted for four - way movement together with an operator &# 39 ; s seat and passenger seats are also supported and mounted on the pivotal frame . a unique hydraulic actuated tilting mechanism is associated with the two frames for semi - automatically tilting the inner pivotal frame and the front wheel , operator and passenger thereon , whenever the operator turns the handlebars in order to make a turn of the vehicle and / or a turn is made which will exert centrifugal force upon the device . a pivotally suspended mass associated with the actuating mechanism aforesaid will automatically through the hydraulic mechanism tilt the inner frame whenever centrifugal force acts upon said suspended mass . this automatic operation as effected by the pivoted mass will function as a safety factor to automatically tilt the inner frame even though the operator neglects to do so . other features include a fail - safe system for the hydraulic mechanism in case of hydraulic failure , a unique shock and spring mechanism for the inner frame , and the use of the frame tubing as part of the overall cooling system for the high powered internal combustion engine .