Quad Wheels 101
Most Roller Skate wheels are made from urethane. Urethane was developed in the 20th century as a replacement for rubber due to a shortage during the world wars. Petroleum was readily available and chemicals produced from oil were used to produce several plastics and then urethane. Urethane was first used for skateboard wheels in the 60’s replacing wooden, hard rubber or clay wheels that would chunk or slide out from under even the lightest skateboarder. The first urethane wheels for roller skates were used for outdoor skating and then harder formulas were produced for top end speed skaters and indoor artistic skaters. Today there are several different methods of processing urethane for roller skate wheels and literally thousands of formulas to produce many different varieties or properties.
Some top end wheels for jam, speed, track and derby skating are made from a material called POLY-BD. This very specific material has exceptional grip while providing excellent rebound, yet remains stiff enough to deliver a quality roll. The POLY-BD also has a very high viscosity which means it pours very slowly when cast and as it cures, tiny air bubbles are caught inside the wheels. These tiny air bubbles show up as holes in the wheel when the running surface is trimmed, as well as, when the wheels wear down and more holes come to the surface. Do not fear the holes, these bubbles do not affect the performance of the wheels and in fact they prove that the material is truly POLY-BD which enhances the performance of the wheels on skating surfaces.
Wheel hardness is determined by an “A” scale rating, the higher the number the harder the wheel. Softer wheels are used for outdoor skating, providing a better rebound for skating on uneven surfaces. Rebound allows for the wheel to toll over uneven surfaces rather than bouncing over them like harder wheels. Hard wheels are used for indoor skating with the softer indoor wheels offering a better a grip than the harder indoor wheels.
Soft wheels below 84A need a hub to reinforce the bearing seat in the wheel. Under normal conditions, an 84A wheel will hold the bearings, but not under extreme conditions. Hubs are used on harder wheels only to lower the weight of larger wheels. Usually nylon or aluminum hubs are much lighter than the urethane they replace. Metal hubs are preferred over nylon hubs to produce a much stiffer wheel and provide a better feel to the top end skaters. Nylon hubs tend to flex while skating.
Narrow Wheels are standard with youth skates, artistic skates, derby skates, outdoor skates, and most rhythm skates. The narrow shape makes the wheels lighter and much easier to maneuver when skating. Wide track wheels are used for most jam skates, track skates and speed skates because the wider surface provides more grip when cornering, especially at high speeds. The speed groove in some RADAR wheels allows the wheel to flex at the groove giving even more grip.
Wheels are offered in an endless array of color; however, different urethane will produce different colors or hues due to the original or natural color of the chemicals. Wheels are cast with powdered pigments to change the urethane color. Wheels color helps the skater know what hardness or grip the wheel is and allows the skater to have a different look.