Description

688 Micro Speed Skate Bearing | Professional Micro Bearing

The common skate version has a width of 5 mm.

5. Wheel Compatibility

The wheel must be designed for Micro Bearings or have a compatible adapter.

6. Spacer

The spacer must be compatible with the 688 system and the axle being used.

7. Shield or Seal Type

The product specifications should clearly state whether the bearing uses Z, ZZ, 2RS, or another type of protection.

8. Ball Material

Whether the balls are made of steel or ceramic must be confirmed from the actual product specifications.

9. ABEC or Stated Standard

If an ABEC rating or another standard is provided, it should be treated as one product specification rather than the only selection criterion.

10. Number of Bearings in the Package

The number of bearings included must match the actual packaging.

Technical Specifications of the 688 Micro Skate Bearing

What Is a Micro Bearing?

Micro Bearing or Mini Bearing refers to a family of smaller bearings used in skating to reduce the weight of the wheel assembly and create more specialized setups.

One of the most common standards in this category is 688.

The typical dimensions of the skate version are:

SkatePro also describes the 688 as a Mini/Micro Bearing with an 8 mm inner diameter, a 16 mm outer diameter, and a 5 mm width.

Why Is the 688 Micro Bearing Used in Speed Skating?

In speed skating, equipment weight is especially important because the entire skate setup is attached directly to the athlete’s foot. The athlete must control and accelerate this mass with every stride.

For this reason, when designing a racing setup, athletes may consider not only the frame and wheels but also the weight of smaller components.

The smaller dimensions of the 688 Micro Bearing can contribute to reducing the total weight of the wheel assembly.

This becomes more significant when the Micro Bearing is combined with other lightweight components, such as:

• Lightweight speed-skating frame
• Suitable speed-skating wheels
• Speed-skating boots
• Micro Bearings
• Suitable spacers
• Adapters, when required
• Compatible axles

Therefore, the purpose of using Micro Bearings should be evaluated as part of the complete skate setup rather than as an isolated bearing.

Difference Between Micro 688 and Standard 608 Bearings

One of the most important points when buying skate bearings is understanding the difference between the 688 Micro and the standard 608 bearing.

A standard 608 bearing generally measures 8 × 22 × 7 mm, while the common skate version of the 688 measures 8 × 16 × 5 mm.

Both bearings may have an 8 mm inner diameter, but their outer diameters are different. Therefore, the 688 and 608 are not direct replacements for one another.

Is a Micro 688 Lighter Than a 608?

Yes. Because of its smaller design, a Micro Bearing generally has less mass than many standard 608 bearings.

For example, Bont states that one of its 688 Mini Bearings weighs approximately 12 grams less per bearing than the 608 bearing used for comparison. Including the spacer, the total weight saving in a four-wheel setup may reach 88 grams.

This figure applies to that specific product and configuration. It should not be considered the standard weight difference for all 688 bearings.

This is one reason Micro Bearings attract athletes who want to build a lightweight speed-skating setup.

Why Does Bearing Weight Matter in Speed Skating?

In a speed sport, the athlete must constantly move the skate, generate acceleration, and transfer force to the wheels.

Reducing equipment weight can be part of designing a lightweight setup. However, removing a few grams from one component alone does not guarantee a specific increase in speed.

Actual skate performance depends on a combination of factors:

Boots + frame + wheels + bearings + spacers + axles + athlete’s weight + technique + skating surface

For this reason, Micro Bearings are most valuable as part of a carefully engineered and balanced setup.

Does a Micro Bearing Make Skates Faster?

This is one of the most important questions when purchasing Micro Bearings.

The answer is that the Micro design alone does not guarantee increased skating speed.

The main benefits of the Micro 688 are its smaller dimensions and its potential to reduce the weight of the complete setup.

The quality of the bearing itself is also important. Performance may be affected by:

• Inner and outer race quality
• Ball quality
• Cage quality
• Lubrication
• Sealing system
• Manufacturing precision
• Assembly quality
• Load placed on the bearing

Therefore, a Micro Bearing should be selected according to the complete skate setup.

What Types of Skates Are Micro Bearings Suitable For?

The 688 Micro Bearing is mainly used in systems designed specifically for Micro Bearings.

In speed skating, this type of bearing has a specialized application. Brands active in speed skating produce dedicated 688 models. Bont offers 688 bearings for inline speed skating, and Powerslide also offers 688 models in its specialized products.

Micro Bearings may be suitable for:

• Speed skates
• Inline speed skating
• Racing setups
• Lightweight setups
• Intermediate and professional athletes
• Athletes who prioritize equipment weight
• Wheels with Micro hubs
• Systems that use a dedicated 688 adapter

Can a Micro 688 Be Installed on Any Skate Wheel?

No.

This is one of the most important points to check before purchasing.

The outer diameter of a Micro 688 is approximately 16 mm, while the outer diameter of a 608 is approximately 22 mm. Therefore, the wheel hub must be designed for Micro Bearings or be compatible with a suitable adapter.

Some manufacturers, including Bont and Powerslide, offer adapters that allow 688 bearings to be used in wheels designed for 608 bearings. The adapter fills the space around the smaller bearing so that it can fit correctly inside the wheel hub.

Before purchasing a Micro Bearing, determine whether:

• Your wheel is designed for Micro Bearings or 608 Bearings
• If the wheel is designed for 608 Bearings, a compatible 688 adapter is available

How Are Micro Bearings and Adapters Related?

In some systems, an adapter makes it possible to install a 688 bearing in wheels originally designed for 608 bearings.

Bont offers 688 adapters for this purpose, and Powerslide also provides a dedicated 688 adapter system.

However, the existence of an adapter does not mean that every adapter is compatible with every wheel or bearing.

The following components must be compatible with one another:

688 Bearing + Adapter + Wheel Hub + Spacer + Axle

What Is the Role of the Spacer in a Micro System?

A spacer is positioned between the two bearings inside a wheel. When the axle is tightened, it supports and helps align the bearing assembly.

Using the correct spacer is particularly important in Micro systems.

For example, Bont’s 688 system refers to the use of a cylinder spacer and states that a conventional self-centering spacer should not be used with that system.

Therefore, it is not enough for the axle diameter to be the same. Any spacer should not be used with every Micro Bearing system.

Structure of a 688 Micro Bearing

Like other deep-groove bearings, Micro Bearings consist of several main components:

Inner race: The part that interfaces with the axle.

Outer race: The part that fits inside the wheel hub.

Balls: Positioned between the inner and outer races, allowing rotational movement.

Cage: Keeps the balls positioned correctly relative to one another.

Shield or seal: Depending on the model, the bearing may include a protective cover or seal to reduce exposure to dirt and contamination.

Bont also describes the basic bearing structure as consisting of the inner race, outer race, balls, and cage, while identifying the shield as an optional protective component.

Difference Between Shields and Seals in Skate Bearings

When purchasing bearings, you may see terms such as Z, ZZ, 2RS, RS, or RZ.

These terms refer to the bearing’s protection or sealing system.

• Z: One metal shield
• ZZ: Two metal shields
• 2RS / RS: Rubber seal or seals

SkatePro explains these terms in its skate-bearing guide and distinguishes between metal shields and rubber seals.

For this product, the exact shield or seal type must be listed according to the actual model specifications. It should not be inferred solely from the product image.

Is a Micro Bearing Ceramic?

Being a Micro Bearing does not mean that the bearing is ceramic.

These terms describe two different characteristics:

• Micro / 688 refers to the bearing’s dimensions and standard.
• Ceramic refers to the use of ceramic components in the bearing structure.

The skating-equipment market includes both steel Micro Bearings and 688 models with ceramic balls.

For example, Powerslide’s WCD Jason Suttels 688 model uses 11 Si₃N₄ ceramic balls, Chrome Steel races, and a T9H Nylon cage.

This example shows that a ceramic construction can be used in a Micro 688 bearing. However, the feature must be confirmed for the exact product model. Ceramic construction cannot be inferred from the word “Micro.”

Unless this product is specifically the ceramic version, the word “ceramic” should not be listed as a product specification.

Micro Ceramic vs. Micro Steel

Both types can use the 688 size, but their internal construction is different.

Therefore, the 688 designation alone does not indicate whether the bearing is steel or ceramic.

Micro Bearings and ABEC: Does a Higher ABEC Mean More Speed?

A common mistake when buying bearings is selecting a product solely based on its ABEC rating.

ABEC refers to a specific level of manufacturing tolerance and precision. However, it does not describe every performance characteristic of a bearing.

SkatePro also emphasizes that ABEC is a manufacturing-precision rating and is not, by itself, a complete measure of performance under load or bearing durability.

When evaluating a Micro Skate Bearing, also consider:

• Race quality
• Ball quality
• Cage
• Lubrication
• Sealing
• Assembly
• Applied load
• Skating conditions
• Type of skate

Therefore, an ABEC 9 rating alone does not guarantee that a bearing is the best choice for every skater or setup.

Does the Number of Balls Matter?

The number of balls is one structural specification of a bearing, but it should not be used as the only measure of quality.

Different 688 models on the market may use different numbers of balls.

For example, Bont uses nine steel balls in one of its 688 models, while Powerslide’s WCD Jason Suttels 688 uses 11 ceramic balls.

It is therefore incorrect to assume that more balls automatically means a better bearing.

The ball track design, dimensions, material, cage, lubrication, and overall manufacturing quality are also important.

How Much Does a Micro Bearing Weigh?

The exact weight of a Micro Bearing depends on its design, material, number of balls, cage, shields, and other specifications.

For this reason, a single fixed weight should not be stated for all 688 bearings.

For example, Powerslide lists the weight of its WCD Jason Suttels 688 model as 3.6 grams. This figure applies only to that specific model and should not be presented as the weight of all 688 Micro Bearings.

If the exact weight is required for a product page, it should be taken from the manufacturer’s official information or measured from the actual product.

Is a Micro Bearing Suitable for Professional Skaters?

The 688 Micro Bearing has a recognized place in specialized speed-skating equipment because of its small dimensions and suitability for lightweight setups.

Specialized versions are produced by brands active in speed skating, including models with ceramic construction for professional applications.

However, a professional setup depends on more than the type of bearing.

A professional setup should have compatibility between:

Boots + frame + wheels + bearings + spacers + axles

Who Is the Micro Bearing Suitable For?

This product may be of interest to:

• Speed skaters
• Professional athletes
• Intermediate athletes
• Inline speed-skating competitors
• Athletes who prioritize setup weight
• Athletes using wheels compatible with 688 Bearings
• Skaters planning to upgrade their speed-skating setup
• Skating coaches and equipment specialists

For ordinary recreational skates, confirm that the wheels support Micro Bearings before purchasing.

Maintaining Micro Skate Bearings

Skate bearings are exposed to dust, moisture, and contamination from the skating surface. Proper maintenance can help preserve their performance.

Keep them away from water and moisture: Continuous exposure to water can corrode metal components and reduce bearing life.

Inspect the bearings after training: If a wheel produces unusual noise, sticks, or rotates unevenly, inspect the wheel and bearing assembly.

Use suitable lubrication: The lubricant should be appropriate for the bearing construction and the manufacturer’s recommendations.

Avoid excessive installation pressure: Incorrect pressure during installation can damage the race, wheel, or other components.

Check the spacer and adapter: Compatible components are especially important in Micro systems.

How Can You Tell That a Micro Bearing Needs Replacement?

The following signs may indicate that a bearing needs inspection or replacement:

• Unusual noise during rotation
• Rough rotation
• Sticking or irregular movement
• Excessive play
• Corrosion or rust
• Damaged shield or seal
• Noticeable deterioration in rotation quality

A final decision should be based on inspecting the bearing and the complete wheel assembly.

What Should You Check When Buying a Micro Skate Bearing?

Before purchasing, check the following:

1. Size

   Make sure the product is a 688 bearing.

2. Inner diameter

   The common skate version has an 8 mm inner diameter.

3. Outer diameter

   The skate version of the 688 has a 16 mm outer diameter.

4. Width

   The common skate version is 5 mm wide.

5. Wheel compatibility

   The wheel must be designed for Micro Bearings or have a compatible adapter.

6. Spacer

   The spacer must be compatible with the 688 system and the axle.

7. Shield or seal type

   Confirm whether the product uses Z, ZZ, 2RS, or another protection system.

8. Ball material

   Confirm whether the balls are steel or ceramic from the actual product specifications.

9. ABEC or stated standard

   If provided, treat it as one specification rather than the only selection criterion.

10. Quantity per package

The number of bearings must match the actual packaging.

An Important Note About 688 Dimensions

When searching online, you may find different specifications for bearings identified as 688.

This is because the bearing industry uses different designations, including 688, 688A, and versions with various suffixes.

For example, NSK lists the 688A with dimensions of 8 × 16 × 4 mm, while the common 688 Mini used in skating is generally listed as 8 × 16 × 5 mm.

Therefore, when buying skate bearings, do not rely only on the number “688.” Check the actual inner diameter, outer diameter, and width.

Is There a Difference Between Micro Bearing and Mini Bearing?

In the skating market, the terms Micro Bearing and Mini Bearing are often used to refer to the same family of small bearings.

Bont also uses the title 688 Mini Micro Bearing for its products.

Therefore, terms such as:

• Micro Bearing
• Mini Bearing
• 688 Bearing
• 688 Micro Bearing
• 688 Mini Bearing

may refer to the same product type or a similar product family. However, the actual dimensions should always be checked before purchasing.

Are Micro Bearings Only for Speed Skating?

No.

688 Micro Bearings are also used in some other skating applications, but one of their important applications is inline speed skating and lightweight setups.

Bont’s guide also discusses 688 bearings in the context of roller skates, inline skates, and skateboards.

However, wheel and installation compatibility must always be checked.

Micro Bearings in a Racing Speed-Skating Setup

In a racing setup, every component should be selected for a specific purpose.

A Micro Bearing may help reduce weight, but the final result depends on the compatibility and coordination of all components.

For example:

Lightweight frame + suitable wheels + Micro Bearings + suitable spacers + speed-skating boots

can create a lightweight and specialized setup.

For this reason, Micro Bearings should not be evaluated separately from the rest of the skate components.

Conclusion: Why Is the 688 Micro Bearing Important for Speed Skating?

The 688 Micro Bearing is a specialized option in skating equipment, particularly for speed-skating setups.

Its smaller dimensions compared with the 608, approximately 8 × 16 × 5 mm in the common skate version, make it possible to use a smaller and lighter bearing in the wheel assembly.

The main benefit of a Micro Bearing should be understood as part of designing a lightweight and properly coordinated setup.

However, the 688 is not a direct replacement for the 608. It must be compatible with the wheel hub, spacer, axle, and, when necessary, the adapter.

Also, being a Micro Bearing does not mean that it is ceramic. If the product contains ceramic balls or other ceramic components, this must be stated separately and confirmed through the official specifications of that exact model.

For anyone building or upgrading a professional speed-skating setup, choosing a 688 Micro Bearing can be an important part of the overall configuration. However, final performance always depends on the compatibility and coordination of the complete system.