Wheels have an enormous influence on speed, stability and overall riding experience. They are usually made of polyurethane, because the only one is durable and runs. However, the life of each wheel is limited. It depends how often you ride. If you want to keep them as long as possible, it's good to swap them on the board. The basic parameters of wheels include the size, indicated in millimeters, and hardness (durometer). Both parameters are a matter of personal preferences and style what you want to ride. Wheel size Small wheels have a lower weight and faster pop, because you have a tail near to the ground and you do not have to reflect as much. Larger wheels provide more stable ride and they better get over with road inequality. Larger wheels are faster. 50-53 mm - small, slower wheels, street, skatepark and bowl 54-59 mm - average size for beginners and more advanced riders, best suited for street, bowl and ramps 60 mm + - Made for cruising and rough surfaces. Hardness o...