Just like skateboards its the bearings that keep the wheels going round. Most bearings are sealed units .
The mud and as much grit as possible is kept out. They come in a couple of sizes depending on your hub and axle .
Just like skateboards its the bearings that keep the wheels going round. Most bearings are sealed units so that the mud and as much grit as possible is kept out. They come in a couple of sizes depending on your hub and axle .