The invention discloses a torque strengthening device for land surfboard adapters, comprising an upper connecting plate and a lower connecting plate, wherein a number of tension springs are connected between the upper connecting plate and the lower connecting plate; the upper connecting plate and the lower connecting plate are provided with the same number of evenly arranged spring connecting blocks on the side facing the tension springs; the number of the tension springs is twice the number of the spring connecting blocks on the upper connecting plate, and each of the spring connecting blocks is provided with two spring connecting holes; the spring connecting blocks of the upper connecting plate and the spring connecting blocks on the lower connecting plate are alternately arranged. The invention can replace tension springs with different torques to obtain different surfing feelings.

A self-propelled, one-wheeled vehicle may include a board having two deck portions each having a concave front footpad configured to receive a foot of a rider, and a wheel assembly disposed between the deck portions. The concave front footpad has a rider detection sensor in the form of a membrane switch conforming to the shape of the footpad (e.g., facilitated by one or more slots formed in the membrane switch). A motor assembly drives the vehicle in response to board orientation and rider detection information. The vehicle may have a secondary battery chargeable via a three-pin charging port including an input pin, a ground pin, and an identification pin configured to receive an expected identification signal from an external charging circuit.

A modular skateboard assembly for facilitating a user to employ a pair of skateboards in the convention of a skateboard or roller skates includes a pair of skateboards which each includes a pair of rollers that roll along a support surface. Each of the skateboards is attachable together such that the pair of skateboards extends along a common axis thereby facilitating the pair of skateboards to be employed in the common convention of skateboards. Furthermore, each of the skateboards is detachable from each other thereby facilitating the pair of skateboards to be employed in the common convention of roller skates. Each of the skateboards includes a pair of foot restraints to restrain a respective one of a user's feet.

An exercise device is described which includes a platform having a first end and a second end opposite the first end; first and second wheels, wherein the first wheel is positioned proximate the first end and the second wheel is positioned proximate the second end and the first and second wheels are configured to roll across a surface as the exercise device is displaced along the surface; a first motor configured to apply a first torque to the first wheel where the magnitude of the first torque is related to the distance of the exercise device from a zero position and the direction of the first torque urges movement of the exercise device toward the zero position. Versions are also described with more wheels and more motors.

A skateboard deck with multiple layers constructed from multiple materials is disclosed. Embodiments for design and manufacture are disclosed.

A skateboard deck with multiple layers constructed from multiple materials is disclosed. Embodiments for design and manufacture are disclosed.

A suspension for a skateboard, comprising a pair of steering knuckles on opposite sides of a chassis frame of the skateboard, a pair of upper control arms connected between the pair of steering knuckles and the chassis frame, a pair of lower control arms connected between the pair of steering knuckles and the chassis frame, and a first spring damper connected between the pair of upper control arms.

A skateboard and a variable-rate elastomeric steering control spring include a boardside unitary body formed of an exterior first elastomer having a first durometer on the Shore “A” scale, and an interior second elastomer coupled to the first elastomer and extending at least a length of the exterior first elastomer, the second elastomer having a second durometer on the Shore “A” scale and a through hole disposed to receive the kingpin of the skate truck, the exterior first elastomer and the interior second elastomer configured with a first irregular anti-slip junction; a roadside unitary body formed of an exterior third elastomer having a third durometer on the Shore “A” scale, and an interior fourth elastomer coupled to the third elastomer and extending at least a length of the exterior third elastomer, the interior fourth elastomer having a fourth durometer on the Shore “A” scale and a through hole disposed to receive the kingpin; and wherein the first, second, third and fourth elastomers comprise at least two durometers on the Shore “A” scale between 65 A and 100 A to enable the boardside unitary body and the roadside unitary body to form the variable-rate elastomeric steering control spring when disposed on the king pin of the skate truck.

A portable energy-saving and environment-friendly electric vehicle is light in weight, small in volume, convenient in electricity charging, and can be disassembled for portability in a backpack. The backpack is further furnished with a crank-handle generator to enable manpower electricity generation and working out simultaneously. This energy-saving and environment-friendly electric vehicle is mainly comprised of two adjustable skateboards and a support rod for adjusting speed and connecting a battery set. The battery set can be conveniently replaced roadside or at other locations. In a situation of power loss, manpower can be used to charge the battery set. Thus, the situation of power loss fully disabling the electric vehicle can be met. In addition, the battery set associated with the generator is reliable for charging mobile phones and computers.

A personal vehicle system including a control system and at least one wheel motor coupled to the personal vehicle system and subject to control by the control system. A control system for a personal vehicle system including steps for calibrating the control system, where the control system includes a sensor system having load sensors incorporated into the personal vehicle system and also having lean forward and lean backward outputs, a user interface that prompts a user to lean forward and backward and allows a user to input a sensitivity value, and an electronic hardware component for calculating a normalization value where the wheel motor current is controlled as a function of the normalization value.