What is a RKP (Reversed Kingpin)?
RKP (reversed kingpin): Trucks that you can find on most of the longboards. They turn more and are more stable. On most of your basic completes you can find Cast trucks in around 180mm.
There are different materials and techniques used for making trucks. You have CNC machined (precision) trucks, Forged trucks, and Cast trucks. Trucks also come in different widths.
Kingpin
The kingpin is the big bolt that goes through the bushings and holds the skate truck parts together. Most kingpins are solid but there are also hollow kingpins. The are lighter but do not compromise the strength or durability.
Baseplate
The baseplate is the base of the truck. This is the part that attaches to the skateboard deck with four bolts. The Kingpin and pivot cup are attached to the baseplate.
Washers
The washers are the metal rings on the bushings. These washers distribute the load on the bushings and make sure the board returns to its center position after turning.
Pivot cup
The pivot cup is the small cup in the trucks baseplate. It makes sure the truck turns effectively at the baseplates intended angle.
Bushings
The thick soft urethane rings are called bushings. They control the way the board turns and pivots.
Hanger
The second main part of the skate truck is called the hanger. The triangular part rests in the pivot cup and is attached to the bushings and baseplate with the kingpin. The hanger holds the axle and is the part that you can grind on.
Axle
The axle passes through the hanger and is made out of titanium or steel. The bearings and wheels turn on the axle.
Axle nut
The axle nut is there to keep the wheels from falling off the axle.
Kingpin nut
The kingpin nut is the nut that holds the truck together. Tightening or loosening the nut influences the way the board steers and how the bushings react to input.
Speed rings
Speed rings are small washers that go on the axles, one in front and one behind the wheel. It prevents the bearings from wearing out against the axle nut or hanger.
Mounting holes
The 4 holes on the baseplate, so you can mount the truck to your board.