Skateboard Wheels
Skate wheels are usually made of polyurethane, a man made plastic that originated in the 1930’s. Wheels com in array of sizes, and even moldings, to fit the preference of each individual skater. Larger wheels range from 55 to 85 millimeters in circumference and roll faster as well as move easily over cracks in pavement. Smaller sizes of wheels range from 48 to 54 millimeters in circumference and help keep the board closer to the ground, require less force for movement and also make for a slower top speed. Wheels are also available in the variety of densities that are measured on a durometer on an A scale. Softer wheels reach a score around A75 and hard wheels measure at A101. In actuality the A scale ranges from 1-100 however manufacturers use the term 101 to symbolize the hardest the wheels could possibly be. Some wheel manufactures now use B scales which have a larger range of density.
Most street skaters prefer smaller wheels ranging from 51 to 54 millimeters in circumference because smaller wheels paired with lighter trucks can make a board lighter. Lighter boards are able to perform trick more easily then heavier boards because the center of gravity is located closer to the deck rather than closer to the body. This also allows the deck to spin easier. Equally street wheels are often hard because harder wheels are easily able to slide on hard surfaces like pavement and asphalt. Harder wheels also allow more balance and stability for the rider.
On the counter side most professional skaters prefer the opposite. Because professional skating many types of ticks that are performed, mainly, on ramps or smooth surfaces professionals usually use larger wheels that are softer. Most commonly professionals use wheels that range from 55 to 65 millimeters in circumference because they can reach higher speeds. Equally softer wheels allow them to maintain the high speeds on smooth surfaces without sliding. Other professional skaters use larger wheels ranging from 60 to 75 millimeters in circumference to obtain the highest potential speeds. Typically the larger the wheel the softer it should be so that the speed can balance with support.