To check if ball bearings are good for skateboards you can spin the wheels and see how good they turn.
If they turn and spin good without resistance then the ball bearings are good but if they don't spin properly and are tight then the ball bearings are bad.
Smooth wheels that are not worn down will make a skateboard go smoother and faster.
Also make sure the skateboard wheel bearings are good and not bad.
Washers help skateboard wheels spin smoothly.
A complete skateboard has a total of eight bearings - two inside each of the four polyurethane wheels.
They look like rings with small steel balls inside.
Bearings fit into either side of the wheel and allow it to spin smoothly on the axle.
Loosen Your Axle Nuts.
Clean Your Skateboard Wheels.
Clean Your Wheel Bearings.
Swap The Wheels Around.
Get Quality Bearings.
Buy New Wheels That Match Your Style.