Three major parts making up a skateboard

Skateboard wheels are designed in many different sizes and hardness. These wheels are made of a rubber like material called urethane. The size and hardness of the wheels affect the smoothness of the ride on a skateboard, how well it handles, and its speed. Skateboard wheels are normally 52 mm to 60 mm and have their own ball bearings built in. Street skateboard wheels are usually very hard, which allows them to slow down quickly and store energy as you move along. Park wheels are usually made of a softer urethane for better bite and handling. Modern skateboard wheels are bidirectional, meaning that they can be attached in either direction unlike the wheels on a car or the back wheel of a bicycle. This means that if the edges start to wear, you can flip the wheels and use them on the other side. Skateboard wheels are attached to the trucks by hex head axle bolts and ABEC (or another company's) ball bearings to provide the free-spinning movement of the wheels.

Skateboard trucks are axles attached to a base plate. Most trucks are made from an aluminium alloy and they are very strong. Trucks come in many different shapes, sizes and colours. These trucks are finished from special cast metal moreover permit the skater to twist the board. Depending how tightly the nut on the kingpin is secured, the trucks can be loose or tight just like the suspension on a car. The main purpose of having trucks that are not fixed is to enable you to turn or "carve" without lifting your front wheels off the ground. The looser your trucks are, the further you will be able to lean in one direction or the other.

Skateboard wheels don't just keep your skateboard rolling, they are also responsible for keeping you on your feet as you tackle different terrain. Wheels are attached to the axles of the trucks with a hex bolt and there are 8 bearings, two inserted into each wheel with a space between.

The skateboard wheels come in different sizes, from 48 to 100 mm, and different hardness. Most skateboard wheels, like mentioned above, are made from urethane, and have a hardness rating stamped on the wheel for example, 95a or 100a  always with an "a" after the number. The higher is the number the harder the wheel. For example, a 101a wheel is harder than a 95a. So a good choice for street riding might be a 100a or 101a. A 95a would do well on ramps and in a skateboard park.

So, a skateboard is made up of three main parts, the deck, the trucks, and the wheels. The deck is the flat part on top where you plant your feet. The trucks are bolted to the bottom of the deck. The trucks are fastened to the bottom of the deck; it also acts as suspension and axles for the deck along with wheels. The wheels fasten onto the ends of the trucks and contain wheel bearings as a result the wheels can turn. Wheels come in different sizes and hardness to support you to modify your ride.