Floater rims are a type of wheel rim that is designed not to rotate with the wheel. This may be accomplished with ball bearings in a manner similar to spinners, though floater rims are weighted to prevent them from rotating when the wheel does. Slight movement may occur when the vehicle starts or stops moving, though the weight will tend to keep the rotation of the rims to a minimum. Floaters are often used in conjunction with large diameter rims and thin tires, which may create the illusion that the tires are not moving at all and that the vehicle is floating over the road.
Spinners were first patented in the US in 1992, and floaters were a later derivation of that basic design. Like floaters, spinner rims typically use ball bearings to allow the rim to spin independently from the wheel. With spinners, this usually results in the rim continuing to rotate when the vehicle comes to a stop. Since the ball bearings have very little friction, the momentum built up by the spinner can allow it to continue moving. This typically gives the illusion that the wheels are still rotating when the vehicle is stopped.
Floater rims use a very similar mechanism to create the the opposite visual effect. This is typically accomplished by weighting the floater rims on the side that is intended to remain on the bottom. The weight tends to overcome what friction exists in the ball bearings, and the motion of the tires fails to transfer to the rims. Since momentum is never built up, the floater rims will tend to not rotate with the wheels or when the wheels have stopped.
The weight itself may cause the rims to rotate slightly when the vehicle begins moving. This rotation will usually be in opposition to the direction the wheels themselves are turning, and then become a gentle back and forth rotation as the weight pulls the rim into a resting position. A similar motion can occur when the vehicle comes to a stop. The amount of this movement may depend on the quality of the ball bearings, the weight of the rim, and other factors.
Floaters and spinners are both popular with enthusiasts of car customization, and rims with this functionality may be very expensive. They may also be accompanied by lift kits that allow the installation of much larger rims, or installed on low rider vehicles. In this case, floater rims may serve to increase the illusion that the vehicle is hovering over the ground.