Skateboard bearings are little metal rings that fit inside you skateboard wheels. They ensure the wheels spin properly, but skateboarding is very abusive toward bearings. They’re rated using a system called the ABEC; giving the bearings an odd number between 1 and 9 to evaluate how smooth a ride they’ll offer.
The best ratings a bearing can receive are a 3 or a 5, translating to not too tight or too lose. Boarders shouldn’t rely too heavily on the rating system though. If a skateboard bearing is durable and appears to work well when you jump and land on the board, then it’s a keeper.
