Drift scooter

Abstract

A drift scooter comprising a longitudinal frame including opposed leading and trailing end portions. A steering assembly is pivotably disposed on the leading end portion and includes a transverse member with two wheels rotatably supported on opposite ends of the transverse member. A stem is fixed in perpendicular orientation relative to the transverse member and a handlebar is connected to the stem. A rear wheel assembly is pivotably disposed on the trailing end portion, wherein the wheel assembly pivots about an upwardly extending pivot axis. The rear wheel assembly is preferably biased toward a centered position, aligned with a centerline of the frame. A resilient member is connected between the frame and a leading portion of the caster. The resilient member may be in the form of an extension spring. Means for adjusting the tension of the extension spring may also be included.

We claim: 
     
         1 . A scooter, comprising:
 A. a longitudinal frame including opposed leading and trailing end portions;   B. a steering assembly pivotably disposed on said leading end portion, said steering assembly including:
 i. a transverse member, 
 ii. two wheels rotatably supported on opposite ends of said transverse member, 
 iii. a stem fixed in perpendicular orientation relative to said transverse member, and 
 iv. a handlebar connected to said stem; and 
   C. a rear wheel assembly pivotably disposed on said trailing end portion, wherein said wheel assembly pivots about an upwardly extending pivot axis.   
     
     
         2 . A scooter according to  claim 1 , including a deck extending along at least a portion of said frame, wherein a top surface of said deck includes a convex portion. 
     
     
         3 . A scooter according to  claim 1 , wherein said rear wheel assembly includes a caster pivotable about said pivot axis. 
     
     
         4 . A scooter according to  claim 3 , wherein said caster is biased toward a centered position, wherein said caster is aligned with a centerline of said frame. 
     
     
         5 . A scooter according to  claim 3 , including an end stop limiting the extent to which said caster can pivot. 
     
     
         6 . A scooter according to  claim 3 , wherein said pivot axis is inclined forwardly with respect to said leading and trailing end portions. 
     
     
         7 . A scooter according to  claim 6 , including a resilient member connected between the frame and a leading portion of said caster. 
     
     
         8 . A scooter according to  claim 7 , including a guard located in front of the caster. 
     
     
         9 . A scooter according to  claim 7 , wherein said resilient member is an extension spring. 
     
     
         10 . A scooter according to  claim 9 , including means for adjusting the tension of said extension spring. 
     
     
         11 . A scooter, comprising:
 A. a longitudinal frame including opposed leading and trailing end portions;   B. a deck extending along at least a majority of said frame;   C. a steering assembly pivotably disposed on said leading end portion, said steering assembly including:
 i. a transverse member, 
 ii. two wheels rotatably supported on opposite ends of said transverse member, 
 iii. a stem fixed in perpendicular orientation relative to said transverse member, and 
 iv. a handlebar connected to said stem; 
   D. a single caster pivotably disposed on said trailing end portion, wherein said caster pivots about an upwardly extending pivot axis that is inclined forwardly with respect to said leading and trailing end portions; and   E. an extension spring connected between the frame and a leading portion of said caster.   
     
     
         12 . A scooter according to  claim 11 , wherein a top surface of said deck includes a convex portion. 
     
     
         13 . A scooter according to  claim 11 , including a caster guard disposed on said frame forward of said caster, and wherein at least a portion of said extension spring is contained within said caster guard. 
     
     
         14 . A scooter according to  claim 11 , including means for adjusting the tension of said extension spring. 
     
     
         15 . A scooter according to  claim 11 , including an end stop limiting the extent to which said caster can pivot. 
     
     
         16 . A scooter according to  claim 11 , wherein said pivot axis is inclined forwardly with respect to vertical between about 5 and about 25 degrees. 
     
     
         17 . A scooter according to  claim 11 , wherein said leading end portion includes a head tube with at least one bearing housed therein, said bearing including an inner race attached to said stem and an outer race attached to said head tube, wherein said inner and outer races include interfering projections that limit the rotation of said stem with respect to said frame. 
     
     
         18 . A method for inducing oversteer in a scooter during a turn on a surface, the method comprising:
 providing the scooter with a rear wheel assembly pivotably disposed about a pivot axis on a trailing end portion of the scooter, said rear wheel assembly including a wheel rotatably mounted on an axle;   biasing said rear wheel assembly toward a centered position, wherein said wheel is aligned with a centerline of the scooter; and   positioning said axle rearward of said pivot axis such that a lateral load generated against said wheel by the surface during the turn causes the rear wheel assembly to pivot away from the centered position in a direction opposite the turn thereby inducing oversteer.   
     
     
         19 . The method according to  claim 18 , further comprising limiting the extent to which said rear wheel assembly can pivot. 
     
     
         20 . The method according to  claim 18 , wherein said scooter includes a deck and further comprising maintaining said deck at a generally level attitude relative to the surface during the turn.