Standard for Roll-Line Wheels
1 - Aluminum Spacer
7mm Axles. (Standard quad Roll-Line Frames)
 

Why Use Spacers in Roller Skate Wheels?

Any Wheel with Bearings, when properly installed on Skate Axles, should use Spacers.

Years ago, when we used Jam Nuts instead of the Nylon inserted Lock Nuts used today. A Jam Nut must be locked down to keep from loosening and coming off. To achieve good Roll from this type of configuration, the sides of the spacer must be absolutely parallel, without any burrs and just a couple of thousandths of an inch wider than the web (that smaller center portion) of the wheel or space between the Bearings. The sizes of the web of the Wheels vary between manufacturers and even between various wheels from the same manufacturer, in some cases. Once again, years ago, the Wheel manufacturers used to supply the Spacers with the Wheels. When the Axle Nut is tightened down on the wheel (with bearings and a spacer), it creates a solid boss of material (the inner race of the inside Bearing, the Spacer, and the inner race of the outside Bearing) that effectively increases the Axle size from 7mm to approximately 14mm. The increasing of the Axle size greatly reduces the possibility of bending or breaking any Axle. By locking the Bearings and Spacer down, it also assures that the center race of each Bearing is not spinning on the Axle, but that the balls of the Bearings are actually doing the work that they are intended to. Tightening the Axle Nut on a Wheel without a Spacer can severely mis-align the center races of the Bearings to the outer races of the Bearings by compressing the inner races towards the center of the Wheel. The Locked Down approach also requires near perfect alignment of the Wheel bore and the web of the Wheel must have very clean square corners to provide a seat for the outer race of the Bearings.