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Are you unsure which bearings you should get? In this guide, we'll explain the most important terms and facts about bearings. We'll also explain which bearings are best for exactly your way of riding or skating.

1. Bearings in general

A wheel needs 2 bearings to rotate on the axle. A bearing can have a big influence on the speed and feel of your riding/skating.
Regardless of the type of bearing you have, you should avoid sand, water and humid conditions at any time, as this will shorten the lifespan of your bearings considerably. Regular cleaning and lubrication of bearings can help to increase their durability and speed. See how to clean your bearings here.

Also, a spacer to fill out the space between the bearings is required, as to avoid destroying the bearings and to create clean rotation when the axles are tightened. The size of the spacer depends on the size of the axle used.

8 mm spacer

6 mm spacer

The quality of bearings depends on a range of factors, such as:

• Material
• Precision (ABEC)
• Lubrication
• Sealed or open (Removable Shield)

Which type of bearing is best for you:

• Are you mainly riding/skating outside, we recommend sealed bearings lubricated with grease,
  as these are most resistant to dirt & dust and require low or no maintenance.
• Are you mainly riding/skating inside, you can use open bearings that spin fast and are easy to clean.
• Are you interested in speed and long distance runs, you can use high precision bearings lubricated with oil. They spin extremely fast and are easy to clean, but dirt can damage them quickly.

2. Mounting

A bearing can usually be pressed in with your thumbs. When the bearing is mounted correctly, it is in line with the wheel core/hub. If it points out in one corner, it's not mounted correctly and will be destroyed upon skating it. If you have a metal core wheel it can be hard to mount the bearing, in this case, use a rubber hammer or a square piece of wood to knock it in.
Never use a metal hammer as it will destroy the bearing and your warranty.
Alternatively, you can use some lubrication to get a bearing in place, if you do then remember all excess lubrication has to be removed afterwards.

3. Bearings in detail

Material

The material of bearings is one of the most important factors for their quality and durability. Most bearings are made of steel. Cheap bearings are usually made of pressed sheet metal or hardened carbon steel, both types are not recommendable for a long lifespan.
Better bearings are made of real bearing-steel, such as chrome, titanium or Swiss steel.
In ceramic bearings (usually used for speed skating) the balls are made of industrial ceramic (Silicon Nitride). Ceramic balls seldom rust and are more durable than steel.

Price and quality are very closely related when it comes to bearings, and you can usually trust the known brands to produce good and durable bearings.

Precision/ABEC

Bearings are categorized according to the industry accepted ABEC-specification. ABEC describes how good bearings are at translating the force applied on them. The higher ABEC classes provide better precision, efficiency, and greater speed capabilities, but do NOT necessarily make the components spin faster. The ABEC rating does not relate to other critical factors, such as the precision of spacers and wheels or the material. All bearings do lose their precision level after some wear.

Please note, that not all brands make use of the ABEC scale (e.g. Bones) and that other scales for bearings exist.
ABEC stands for Annular Bearing Engineering Committee.

Lubrication

Bearings can either use oil or grease as lubrication. A bearing must never run "out" of lubrication, if it does it will melt and lose speed or block completely.

• Oil: Results in high speed because of less resistance in the lubrication material. A thin oil gives higher speed, but also requires more frequent maintenance.
• Grease: It resists water and dirt more than regular oil. Requires almost no maintenance, but creates higher resistance, also means less speed.

Notice: Water can remove all lubrication! If this happens and the water dries, your bearings will get very hot and possibly melt and make sounds, the next time you use them. This means you need to replace the bearings. In some cases, if you have not rolled on them in between, it can be saved if cleaned and oiled properly before the next use.

Shields/Seal

In order to prevent dirt, sand and water to enter the bearings, a shield or seal is often placed on each or one side of the bearing.

• A Shield is usually a metal shield mounted to the outer ring and has a little space to the inner ring (also called a dustproof bearing). Bearings with shields have little friction and therefore rotate more easily, giving you more speed. On the other side is the bearing not perfectly protected against water and dirt.
• A Seal (pictured below) is made of steel-enforced rubber, which is mounted to the outer ring, and slightly touches the inner ring. It gives better protection and almost no maintenance, but also higher friction and slightly lower speed.

4. The standards and bearing precision explained

There are a number of factors covered by the ABEC grades. One is the eccentricity (roundness) of the track in the inner ring. The table below is the maximum eccentricity allowed.

Type mm Inches ABEC 1 0. mm (0.") ABEC 3 0. mm (0.") ABEC 5 0. mm (0.") ABEC 7 0. mm (0.") ABEC 9 0. mm (0.")

This means, that the higher the ABEC classification, the smaller the deviation in the parts of the bearing = more power is transferred to the wheel.

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ABEC and ILQ cannot be directly compared since ILQ is a brand name and ABEC is a standard.

ABEC bearings are measured on the accuracy in production and not the durability or function under a load. Twincam, the manufacturer of ILQ rates the quality of their bearings on a scale similar to the ABEC scale. But despite that, ILQ bearings has 6 balls, where ABEC bearings have 7.

To clarify the difference, ILQ is not a standard, such as ABEC bearings. ILQ should, therefore, be seen as an unrated bearing from a professional inline bearing manufacturer and is not optimal for industrial machinery.

Bones bearings are made purely for skating - and cannot be compared with ABEC specifications.

The vocabulary for bearings and their shields is listed below (the type of the bearing is usually printed on the bearing together with the size, e.g.: 608ZZ).

608

• Standard bearing
• 22 mm outer diameter
• 7 mm width
• 8 mm inside diameter

688

• Mini/Micro bearing
• 16 mm outer diameter
• 5 mm width
• 8 mm inside diameter

Z

• Shield, 1 metal shield
• Open in the other end for easy maintenance (always turn the open side to the inside of the wheel when mounting)

ZZ

• Shield, 2 metal shields
• The shields are mounted with a small C-ring, which must be removed in order to remove the shield for maintenance.

2RS/RS/RZ

• Seal, 2 steel armed rubber seals
• Seals mounted without C-rings. It is possible to remove the seals carefully with a needle for maintenance.

BRS

• Seal, 2 steel armed rubber seals (contact free)
• Seals mounted without C-rings. With extra good protection against water entering the bearing.

Bearing Buying Guide

Shop Bearings with Confidence!

By Forest | July

This guide covers the basic factors that influence a bearing&#;s cost and performance so that you can make an informed decision when purchasing your next set. Topics covered on this page include:

• Size
• Rating
• Materials
• Ball Count
• Serviceable vs Sealed

Size

The vast majority of bearings used in skating applications are sized for 8mm axles; these are also known as standard 608 bearings. 7mm (627) bearings are relatively uncommon by comparison, while other sizes such as Micro (688) are only rarely seen. As the only true restriction when it comes to bearings, we recommend buying the size that your axles and wheels are designed to use.

Materials

Bearings are most efficient when friction is at its lowest, so materials play a pivotal role in performance. Many bearings are constructed from steel alloys that are tough and affordable. Keep an eye out for components or coatings made from bronze, titanium, and especially ceramic &#; these will improve a bearing&#;s resilience, durability, and performance. Ceramic bearings are widely regarded as the best that money can buy.

Rating

Many manufacturers seek out an ABEC rating that scores bearings on a scale of 1-9. Higher ABEC scores indicate a more precisely made bearing, however, the system was developed for industrial applications, not skating. Therefore, a number of companies forgo ABEC ratings on their skate bearings and opt for &#;skate rated&#; labels that signifies that the bearing was tested and approved for skating.

Number of Balls

Skate bearings traditionally have seven balls that provide a good balance of acceleration, top speed, roll, and durability. Six ball bearings use larger balls that generate less friction and roll longer, making them perfect for sustained skating at high speeds (think 27-in-5 or banked track). Eight ball bearings have smaller balls that better withstand side loads, which makes them great for high speed or aggressive turning (think park skating). Derby is a combination of all of those things, so find your magic number!

Serviceable vs Sealed

Serviceable bearings feature removable shields or plastic retainers that allow you to clean and re-lubricate your bearings. Most high-end bearings will be serviceable to allow you to maintain optimal roll and extend the life of the bearing. Sealed bearings have non-removable shields that help keep out harmful debris, but they cannot be cleaned and would have to be replaced when not performing as desired. Sealed bearings are great for those skaters not interested in bearing maintenance but tend to lack the performance offered by serviceable bearings.

Shop All Bearings

Contact us to discuss your requirements of Ball Bearings Supplier. Our experienced sales team can help you identify the options that best suit your needs.