Skateboarding on a skate- or longboard takes a number of parts:
Bushings are probably the first thing to replace after some wear and tear (Verschleiß). There are three bushings:
When the board becomes slow to roll, it is time to replace the bearings inside the wheels.
Manufacturing precision (ABEC) ratings play only a minor role, as of 2020 ABEC-7 should be the minimum but does not guarantee good rolling either. Sizes seem to be standardized.
That was only a small journey! I hope you enjoyed it and know what kind of parts to replace now. Have a good day!EOF (Sep:2021)