An apparatus, comprising: a frame; a steering mechanism coupled to the frame; a front wheel coupled to the frame; a rear wheel including a rear wheel axle and a rear wheel hub coupled to the frame; a first and a second foot link, with a first end of each foot link coupled to the frame, and a second end of each foot link coupled to a respective one of a first crank arm and a second crank arm, with each crank arm coupled to the rear wheel axle, wherein each foot link has a load wheel and a foot platform mounted thereon for an operator to stand on; and a crank assembly including the crank arms and a crank arm bearing coupled to the frame, wherein the first and second crank arms are rotatably connected at the crank arm bearing to a drive sprocket; and wherein during pedaling the operator exerts a force on the foot platforms and thereby to the foot links to cause the load wheels to roll down the slope of foot link guide tracks towards the rear of the apparatus and to rotate the crank arms about the crank arm bearing to thereby turn the drive sprocket, which is connected to a rear wheel sprocket by drive means, said rear wheel sprocket being connected to the rear wheel hub of the rear wheel to transfer power from the first and the second foot link to the rear wheel via the crank assembly so as to propel the apparatus; the apparatus being characterised in that the crank assembly further includes, for each crank arm, a crank extender rotatably connected to the second end of the corresponding foot link at a foot link bearing, wherein a length of each crank arm is adjustable and wherein, for each crank arm, a distance between a center of the crank arm bearing and a center of the foot link bearing is a crank arm length that can be adjusted to modify a stride length of the operator. a frame; a steering mechanism coupled to the frame; a front wheel coupled to the frame; a rear wheel including a rear wheel axle and a rear wheel hub coupled to the frame; a first and a second foot link, with a first end of each foot link coupled to the frame, and a second end of each foot link coupled to a respective one of a first crank arm and a second crank arm, with each crank arm coupled to the rear wheel axle, wherein each foot link has a load wheel and a foot platform mounted thereon for an operator to stand on; and a crank assembly including the crank arms and a crank arm bearing coupled to the frame, wherein the first and second crank arms are rotatably connected at the crank arm bearing to a drive sprocket; and wherein during pedaling the operator exerts a force on the foot platforms and thereby to the foot links to cause the load wheels to roll down the slope of foot link guide tracks towards the rear of the apparatus and to rotate the crank arms about the crank arm bearing to thereby turn the drive sprocket, which is connected to a rear wheel sprocket by drive means, said rear wheel sprocket being connected to the rear wheel hub of the rear wheel to transfer power from the first and the second foot link to the rear wheel via the crank assembly so as to propel the apparatus; the apparatus being characterised in that the crank assembly further includes, for each crank arm, a crank extender rotatably connected to the second end of the corresponding foot link at a foot link bearing, wherein a length of each crank arm is adjustable and wherein, for each crank arm, a distance between a center of the crank arm bearing and a center of the foot link bearing is a crank arm length that can be adjusted to modify a stride length of the operator.