I'm gonna buy a FKD Sawblade ABEC 7 bearings sometime and I'm just curious.
Pretty much nothing. It is a measure of precision for high speed machinery where vibrating shafts are a problem. Way higher speeds than wheels on skate boards or inline skates. In some cases, higer abec ratings can cause extra drag in the bearings because of the smaller gaps inside the bearing. Some companies (Zero Drag, Bones, Twin Cam) have designed their best bearings to have lower drag by not meeting even the ABEC 1 standard but with the tolerances close in the areas needed to make them run true in your wheels.
