Do You Know What Are The Standard Skateboard Bearings Sizes

Skateboard bearings are small components that play an outsized role in your riding experience. Located inside each wheel, they allow the wheel to spin freely around the axle of your truck. While they may look simple, understanding their specifications, materials, and maintenance requirements can help you make better purchasing decisions and extend the life of your equipment.

This guide provides a comprehensive overview of skateboard bearings, including standard dimensions, material options, selection criteria, and proper maintenance techniques.

What Are Skateboard Bearings?

A skateboard bearing is a precision component designed to reduce friction between the wheel and the axle. Despite their small size, they consist of several precisely engineered parts:

The interaction between these components determines how smoothly and how long your bearings will perform.

Standard Skateboard Bearing Sizes: The 608 Standard

The 608 Bearing: Industry Standard

When discussing skateboard bearing sizes, one number dominates: 608. This is the industry standard size for the vast majority of skateboards, longboards, roller skates, and even many scooters.

• Standard 608 Bearing Dimensions:
• Inner Diameter (Bore): 8 mm
• Outer Diameter: 22 mm
• Width: 7 mm

This 8mm bore is designed to fit the standard 8mm axle found on virtually all modern skateboard trucks. This directly answers a common question: “Do I need 7mm or 8mm bearings?” Since modern trucks use 8mm axles, 8mm bearings (608) are the appropriate choice.

Other Bearing Sizes

While 608 bearings dominate the market, other sizes exist for specific applications:

Types of Skateboard Bearings: Materials and Seal Designs

Skateboard bearings are categorized primarily by two factors: the materials used and the type of sealing mechanism.

By Material

Chrome Steel Bearings

Chrome steel (typically SAE 52100) is the most common bearing material. These bearings offer reliable performance at an accessible price point. They provide good durability under normal skating conditions but require maintenance to prevent rust, particularly if exposed to moisture.

Ceramic Bearings

Ceramic bearings typically refer to hybrid bearings with steel rings and ceramic balls (usually silicon nitride). Ceramic balls offer several characteristics:

• Harder than steel, potentially reducing wear
• Lighter than steel, reducing rotational mass
• Generate less friction and heat
• Naturally corrosion-resistant

Full ceramic bearings (ceramic rings and balls) exist but are less common in skateboarding due to their brittleness under impact.

Stainless Steel Bearings

Stainless steel offers improved corrosion resistance compared to standard chrome steel. This makes them suitable for skaters in humid climates or those who occasionally skate in damp conditions, though they typically cost more than standard steel.

Titanium Bearings

Titanium bearings are relatively rare and typically found in premium applications. Titanium components offer excellent corrosion resistance and weight savings, though at a significantly higher price point.

By Seal Type

The seal design significantly affects bearing performance and longevity:

Rubber Sealed Bearings (2RS)

Rubber seals press firmly against the inner ring, creating an effective barrier against contaminants. These provide the best protection for street skaters who encounter dirt, debris, and moisture. The trade-off is slightly higher friction, but the extended bearing life typically justifies this for most riders.

Metal Shielded Bearings (ZZ)

Metal shields are non-contact rings that block large particles while allowing minimal friction. They offer less protection against fine dust and moisture but may spin slightly more freely. These are often preferred by park or vert skaters in cleaner environments.

Non-Contact vs. Contact Seals

Some rubber seals are designed as “non-contact,” meaning they don’t physically touch the inner ring. These offer a middle ground between protection and low friction but are less common in skateboarding.

How to Choose Skateboard Bearings: Beyond the ABEC Rating

Understanding ABEC Ratings

The ABEC (Annular Bearing Engineers’ Committee) rating system is frequently mentioned in bearing discussions. This system classifies bearings based on manufacturing tolerances:

A higher ABEC rating indicates tighter manufacturing tolerances, which theoretically allows for smoother operation at very high speeds.

What ABEC Ratings Don’t Tell You

However, the ABEC rating has important limitations when applied to skateboarding:

• It does not consider material quality
• It does not evaluate seal effectiveness
• It does not measure impact resistance
• It does not indicate lubricant quality
• It does not predict durability in skateboarding conditions

A bearing with a high ABEC rating but poor seals and low-quality steel may fail faster than a well-sealed, lower-rated bearing made from quality materials.

Practical Selection Criteria

When selecting skateboard bearings, consider these factors instead of focusing solely on ABEC ratings:

1. Sealing Requirements

• Street/urban skating: Rubber seals recommended
• Park/vert skating: Metal shields may suffice
• Wet/humid conditions: Rubber seals essential, stainless steel recommended

2. Material Considerations

• Standard use: Quality chrome steel offers good value
• Corrosion concerns: Stainless steel or ceramic hybrids
• Weight-conscious: Ceramic hybrids or titanium (premium options)

3. Maintenance Commitment

• Low maintenance preference: Better seals reduce cleaning frequency
• Regular maintenance: Any bearing type can perform well with proper care

4. Budget

• Entry-level: Chrome steel with rubber seals
• Mid-range: Improved steel quality, better seals
• Premium: Ceramic hybrids or specialty materials

Skateboard Bearing Materials: A Technical Overview

Understanding material properties helps explain performance differences between bearings.

Steel Bearings

Most skateboard bearings use high-carbon chrome steel (SAE 52100 or equivalent). This material offers:

• High hardness (Rockwell C 60-65)
• Good wear resistance
• Excellent load capacity
• Reasonable cost

The primary limitation is susceptibility to corrosion. lubrication and storage help mitigate this

Ceramic Hybrid Bearings

Hybrid bearings combine steel rings with ceramic balls (typically silicon nitride). Silicon nitride ceramic offers:

• Hardness approaching diamond (about 2x harder than steel)
• Lower density (about 60% lighter than steel)
• Smooth surface finish reducing friction
• Complete corrosion resistance
• Lower thermal expansion

The ceramic balls do not deform under load as much as steel, potentially reducing friction. However, they are more expensive and can be brittle if subjected to hard impacts.

Stainless Steel

Stainless steel bearings (typically AISI 440C) offer:

• Good corrosion resistance
• Slightly lower hardness than chrome steel
• Higher cost than chrome steel

These are valuable for skaters in coastal areas or humid climates.

Comprehensive Skateboard Bearing Maintenance Guide

Proper maintenance significantly extends bearing life and maintains performance. Here’s a systematic approach to bearing care.

When to Clean or Replace Bearings

Auditory Indicators

• Grinding or gritty sounds during wheel spin
• Unusual noise while riding on smooth surfaces

Tactile Indicators

• Wheels don’t spin freely when flicked
• Noticeable friction or roughness when spinning wheels by hand
• Uneven resistance between wheels

Visual Indicators

• Visible rust on bearing surfaces
• Dirt or debris visible around seals
• Damaged or missing shields
• Lubricant leaking from bearings

Severe Damage Indicators

• Flat spots on balls (feels like vibration)
• Cracked or deformed shields
• Excessive radial play (wobble)
• Rough spots in rotation

Cleaning Process

Materials Needed:

• Cleaning solvent (acetone, isopropyl alcohol, or dedicated bearing cleaner)
• Small container for soaking
• Safety pins or fine needles for seal removal
• Clean, lint-free cloth
• Skateboard bearing lubricant
• Paper towels

Step-by-Step Cleaning:

• 1.Removal：Remove bearings from wheels using the truck axle or a bearing removal tool. Avoid prying against the shields.
• 2.Seal Removal：Carefully remove rubber seals using a fine needle or safety pin. Work around the circumference gently to avoid bending the seal. Place seals aside in a safe location.
• 3.Cleaning：Place bearings in cleaning solvent. Swirl and soak for 10-15 minutes. Repeat with fresh solvent if heavily contaminated. Shake bearings gently in solvent to loosen debris.
• 4.Drying：Remove bearings from solvent and place on paper towels to dry. Allow to air dry completely. Do not use compressed air, as this can cause bearings to spin at damaging speeds.
• 5.Lubrication：Apply one small drop of skateboard bearing lubricant to each bearing. Spin the bearing slowly to distribute lubricant evenly.
• Avoid over-lubrication, which attracts dirt.
• 6.Seal Replacement：Press seals back into place carefully. Ensure they seat evenly around the circumference.
• 7.Reinstallation：Reinstall bearings into wheels and reassemble your skateboard.

Maintenance Frequency Guidelines

Common Maintenance Mistakes

Using WD-40 as Lubricant

WD-40 is a solvent and water displacer, not a lubricant. It will dissolve existing lubricant and then evaporate, leaving bearings dry and susceptible to damage. Use dedicated bearing oil instead.

Over-Lubrication

Excess lubricant attracts and holds dirt and debris, forming an abrasive paste that accelerates wear. A small drop per bearing is sufficient.

Removing Seals Unnecessarily

Bearings that are properly sealed don’t require frequent internal cleaning. Removing seals increases contamination risk.

Using Harsh Cleaning Methods

Abrasive cleaning, wire brushes, or ultrasonic cleaners can damage bearing surfaces. Gentle solvent cleaning is sufficient.

Spinning Bearings with Compressed Air

High-speed spinning without load can damage bearings and is potentially dangerous.

Frequently Asked Questions

Do all skateboard bearings fit all skateboard wheels?

Most modern skateboard wheels are designed to accept standard 608 bearings. The wheel core is manufactured with a 22mm diameter to accommodate the bearing’s outer ring. Bearings are held in place by the wheel’s core and the axle nut.

How do I know what size bearings I need?

For standard skateboards and longboards, you need eight 608 bearings (two per wheel). Check your truck axle diameter; if it’s approximately 8mm, 608 bearings are correct.

What’s the difference between ABEC 5 and ABEC 7 bearings?

ABEC 7 bearings are manufactured to tighter dimensional tolerances than ABEC 5 bearings. However, this tolerance rating doesn’t account for material quality, seal effectiveness, or suitability for skateboarding conditions. A well-sealed ABEC 5 bearing may outperform a poorly sealed ABEC 7 bearing in real-world skating.

How often should I replace skateboard bearings?

With proper maintenance, quality bearings can last years. Replace bearings when they show signs of damage (rust, flat spots, cracked shields) or when cleaning no longer restores smooth rotation.

Can I use automotive bearings in my skateboard?

Automotive bearings are designed for different load profiles, speeds, and environmental conditions. Skateboard-specific bearings or general-purpose 608 bearings manufactured to appropriate specifications are recommended for proper fit and performance.

Are ceramic bearings worth the extra cost?

Ceramic hybrid bearings offer advantages in weight, friction reduction, and corrosion resistance. Whether these benefits justify the higher cost depends on individual priorities. For competitive skating or maximum performance, some skaters find the investment worthwhile. For recreational skating, quality steel bearings with proper maintenance provide excellent performance.

Do bearings come pre-lubricated?

Yes, new bearings come with lubricant from the manufacturer. The type and quantity vary by manufacturer and intended use. Some bearings use oil, others use grease. This initial lubrication is sufficient for normal use.

Are all skateboard bearings the exact same physical size?

Yes, for standard skateboards, longboards, and most cruiser boards, the external dimensions are identical: 22mm outer diameter (OD), 8mm bore (inner diameter), and 7mm width. This is the 608 standard. However, “mini” bearings (e.g., 608-2RS with a 6mm bore) exist for some smaller wheel applications like fingerboards or certain roller skates, but they are not interchangeable with standard skateboard wheels.

Will using a higher ABEC rating make my skateboard faster automatically?

Not necessarily. An ABEC rating measures manufacturing precision and tolerance, not speed or rolling resistance. A high ABEC rating (e.g., ABEC 7 or 9) allows for higher rotational speeds, but skateboards rarely reach those RPMs in normal use. For skating, the quality of the lubricant, seal design (low friction vs. high protection), and overall build quality often have a more immediate impact on perceived speed and roll than the ABEC number alone.

What is the actual speed difference between steel and ceramic hybrid bearings?

Ceramic hybrid bearings (steel races with ceramic balls) offer a marginal reduction in rolling resistance, typically less than 2-3% in controlled tests. Their primary advantages are not speed but rather hardness (ceramic balls do not deform), corrosion resistance, and heat dissipation. They maintain their performance longer under harsh conditions. The real-world speed difference on a flat surface is minimal for most skaters; the benefit is more noticeable during long, high-speed downhill runs where heat buildup and precision matter.

Can I use standard skateboard bearings in any longboard wheel?

Yes, the vast majority of longboard wheels are designed for the standard 608 bearing (8mm axle). The only exception is some very old or specialty longboard trucks that use a 10mm axle. For those, you would need a 608 bearing with a 10mm bore, often called a “608-10” or “skateboard bearing with 10mm hole.” Always check your axle diameter before purchasing.

How many skateboard bearings do I need for one complete skateboard?

You need eight bearings. Each of the four wheels requires two bearings – one pressed into each side of the wheel hub. A standard set of skateboard bearings contains eight individual units. Roller skates or inline skates have different counts (e.g., 16 for quad skates), but skateboards and longboards consistently use eight.

Is it safe to remove the rubber seals from my bearings to make them spin faster?

Removing the seals (or using “seal-less” bearings) slightly reduces friction but exposes the internal balls, raceways, and lubricant directly to dust, sand, water, and grit. This will drastically shorten bearing life, often from months to days or hours when skating outdoors. It is not recommended for standard street or park skating. Only consider seal removal for very clean indoor surfaces (e.g., a polished skate park) and only if you are prepared to clean and relubricate them after every session.

What is the typical lifespan of a skateboard bearing in hours of use?

Under normal street or park skating conditions (some dirt, impacts, moisture), a quality steel bearing with rubber seals lasts approximately 50 to 150 hours of active rolling time before noticeable degradation in performance. Ceramic hybrids can last 2-3 times longer. Factors that shorten life most: water, sand, and direct impacts (e.g., landing sideways). Using your actual weekly skating hours, you can estimate when cleaning or replacement is needed.

My new bearings feel slow. Is that normal?

Yes, this is common. New bearings are typically packed with a heavy, high-viscosity grease for protection during shipping and initial use. This grease creates higher initial rolling resistance. After 1-3 hours of skating, the grease will warm up and redistribute, and the bearings will “break in,” becoming noticeably faster. If you want immediate low friction, you can replace the factory grease with a light oil (e.g., Bones Speed Cream), but this will require more frequent cleaning.

Can I mix different bearing types (e.g., two ceramics and two steels) on the same board?

Technically yes, but it is not recommended for performance. The wheels with ceramic bearings may roll slightly differently than those with steel bearings, which can create uneven drag and affect your board’s tracking (tendency to turn or pull to one side). For consistent handling, always use eight identical bearings of the same model and wear state on a single board.

Conclusion

Skateboard bearings are precision components that significantly affect your riding experience. Understanding standard sizes (particularly the 608 standard), material options, and maintenance requirements helps you make informed decisions and extend equipment life.

The 608 bearing with 8mm inner diameter, 22mm outer diameter, and 7mm width remains the universal standard for most skateboarding applications. Material choices range from standard chrome steel to ceramic hybrids, each with distinct characteristics. Seal selection—rubber versus metal—should align with your typical skating environment.

Proper maintenance, including regular cleaning and appropriate lubrication, substantially extends bearing life and maintains performance. Avoiding common mistakes like using inappropriate lubricants or over-lubricating helps protect your investment.

For those seeking quality skateboard bearings, manufacturers with experience in precision bearing production—such as companies serving automotive and industrial sectors—often apply the same quality standards to their skateboard bearing lines. DUHUI Bearing, with two decades of manufacturing experience across multiple bearing categories, represents one example of such manufacturers serving the skateboard market.

Whether you’re a skater maintaining your equipment or a business sourcing bearings, understanding these fundamentals helps ensure you select appropriate products for your specific needs.