Why is my wheel not spinning freely?

If you notice your wheel slows down very quickly when spinning it, you may have an issue with your bearing stack. The bearing stack comprises of the two bearings and spacer placed inside the wheel core. A cross-section of a properly installed bearing stack is shown below.

If the bearings aren't pressed fully inside of the wheel core, thrust loads on the inner race can cause improper alignment of the ball bearings, significantly slow down the wheel, and even cause damage to the bearings. To fix this, make sure to fully seat the bearings into the wheel core. In some wheel cores, the fit with the bearings is very tight.

Similarly, if the spacer is too small, an identical situation occurs. Not all spacers have the same size. If you think your spacer is too small, you may need to try other spacer brands. Endless Twincam ILQ9 bearings and sonic floating spacers are paired optimally to ensure proper spacing between bearings.

Other causes of slow spinning wheels include:

• Dirty bearings (indicated by loud bearings, vibrations or grinding while spinning)- follow online bearing cleaning guides (for serviceable bearings) or replace bearings
• Bearing shield rubbing wheel boss (only applicable for bearings with removable shields) - make sure the bearing shield is fully depressed and not protruding from the bearing.