On a skateboard, trucks are the metal assemblies mounted directly to the underside of the deck that connect the wheels to the board and enable turning. Often overshadowed by the deck or wheels, they form the critical suspension and steering system, translating the rider's subtle shifts in weight into smooth, responsive carve lines. Understanding their function is essential for anyone looking to tailor their setup to a specific style of riding.
Anatomy of a Truck Assembly
The truck assembly consists of several key components working in harmony. The baseplate is the flat, rectangular piece that screws directly into the deck's mounting holes and sits flush against the grip tape. Rising from the baseplate is the kingpin, a thick bolt that acts as the central pivot point. Sandwiched around this pin are the bushings, which are pliable polyurethane rings providing the resistance that creates a stable yet flexible turning force. Completing the structure are the hanger, axle, and nuts that secure the wheels in place.
The Kingpin and Pivot Point
The kingpin is a hardened bolt that runs vertically through the center of the truck, just behind the axle. It is this pin that allows the entire assembly to rotate left and right. The top of the kingpin is usually capped with a nut, and the tightness of this nut, in relation to the bushings, dictates how easily the board turns. A looser kingpin facilitates sharp, immediate turns, while a tighter setting offers more stability at high speeds.
Bushings: The Shape of Your Turn
Bushings are the soft, donut-shaped polyurethane rings located above and below the kingpin. They are the primary source of resistance when turning, acting like small springs to return the wheels to a neutral position after a lean. The durometer (hardness) and shape of these bushings are the main factors in determining the "feel" of the truck. Softer bushings result in a deep, loose turning radius favored by surfers, while harder bushings provide a tight, responsive feel suitable for technical street skating.
Barrel Bushings: Offer a progressive turn, making them versatile for cruising and everyday use.
Cone Bushings: Provide a more immediate turn at the start of the lean, preferred by technical riders for flick tricks.
Truck Width and Deck Compatibility
Truck width is measured from the outer edges of the axle nuts and must closely match the width of the skateboard deck for optimal performance. Standard trucks are designed for decks between 7.75 and 8.25 inches. If the trucks are too narrow for the deck, the wheels will hang over the edge, risking wheel bite on turns. Conversely, trucks that are too wide for a narrow deck can make the board feel sluggish and unresponsive.
Standard vs. Reverse Kingpin
While the standard kingpin (SGK) setup has the kingpin facing inward toward the center of the board, the reverse kingpin (RKP) configuration flips this orientation so the kingpin faces outward. RKP trucks are the industry standard for longboards and cruisers, offering a smoother, more stable ride at higher speeds with a greater turning radius. SGK trucks remain the preference for traditional skatepark and street skating due to their compact size and flick capability.
Height and Its Impact on Performance
The height of a truck, determined by the distance between the baseplate and the top of the axle, significantly affects stability and clearance. Low trucks sit close to the ground, shortening the distance the wheels have to travel when leaning, which results in a stable platform ideal for technical tricks and high-speed cornering. High trucks, conversely, offer greater wheel clearance for large wheels and provide enhanced leverage for turning, making them excellent for carving and transitioning.
