Fluido 57mm Freestyle Wheels

The RollLine Fluido 57mm small profile width professional freestyle wheels are designed to be used on many types of skating surfaces including standard wood floors coated with plastic or poly urethane, but also unusual surfaces like tile basketball and volleyball courts, indoor and outdoor tennis courts and concrete or terrazzo surfaces. Fluido wheels use a stiff Delrin hub which is strong, light, and with close tolerances for roundness, trueness, and for the cage where the bearings and spacers are mounted. The tread is an injection molded mix of elastomeric formula, which provides strong grip, while providing great roll and a higher rebound than most other RollLine thermo-plastic and urethane wheels (except the Helium wheels). 
 
The tread color identifies which hardness the wheels are.
45D = Fuchsia
47D = Blue
49D = Grey
53D = Cappuccino
 
Set of 8 wheels
 
The softer the wheel, or lower shore “D” hardness number, the more the grip and slightly less roll. The harder the wheel, or higher shore “D” number, the more the roll, with slightly less grip.  The shore “D” scale is used for rubber and plastics, while the shore “A” scale is used for urethane.
 
It is almost always recommended to use spacers in the wheels, when using standard 7mm bearings.