The SRG "Abec 11 bearings" are solid, and they do what bearings are supposed to do--spin and last. Over the past 6 years, we've been selling complete longboards in our online shop, and we've sourced a lot of stock bearings during that period. Some were good, some decent, and some not so good. These are the best Abec 11 bearings we've found. They're good, they're cheap, and they last. We believe in them enough to put our name on them. Pop them in and don't worry about getting them dirty.  

SRG Bearings are the first precision bearing designed for skateboarding that incorporates an integrated spacer and washer. The perfectly faced inner races provides precise spacing and perfect alignment so that the locknuts can be snuggly tightened without pinching or binding the bearings. The bearings work together to more evenly share the sideloads and keep your wheels flat on the ground for better wear. This patented system is guaranteed to give you the fastest and strongest bearings on the planet. They fit all skateboard wheels that use the industry standard .400" spacing (10.16mm). Tested by the world's fastest skateboarders in the most demanding conditions, Biltins provide unparalleled performance in all types of skating. They are also the easiest bearings to use, making those nasty little washers and annoying spacers a thing of the past. Designed to be easier to maintain than other bearings, Biltins are simply the best and fastest skateboard nsk bearings on the market today.

Tolerance classes for ball bearings were defined by a committee within the ABMA known as the “Annular Bearings Engineers Committee” (ABEC). These tolerances are commonly referred to as ABEC rating, or grade. Tolerance classes for roller bearings are covered by the RBEC classifications contained within the same standard. These classes are defined in ABMA standard 20 – Radial Bearings of Ball, Cylindrical Roller, and Spherical Roller Types and ABMA standards 12.1 and 12.2 – Instrument Ball Bearings. The ABEC (and RBEC) tolerance classifications specify both tolerances of size and form for the individual inner and outer rings. The critical features of the rings include the bore (or inner diameter of the inner ring), the outer diameter of the outer ring, the ring widths, and the raceways of each ring. Tolerances of form include roundness, taper, runout, and parallelism.

ABMA standard 20 defines 5 classes: ABEC 1, ABEC 3, ABEC 5, ABEC 11, and ABEC 9. Instrument series ball bearings are defined in standards 12.1 and 12.2 and carry the suffix “P”. Extra thin and thin section ball bearings defined in standards 12.1 and 12.2 carry the suffix “T”. The higher the number of the classification, the tighter the tolerances become resulting in higher precision of the assembled bearing. When the classification system was first set up, machine tool technology was such that manufacturers mass produced only ABEC 1, and sometimes ABEC 3. koyo Bearings for the higher classifications were selected from the production runs of the lower classification. Today, the technology has advanced to the point where manufacturers can produce ABEC 11 and ABEC 9 bearings routinely.