Bike bearings: definition, materials, types, sizes and maintenance

Bicycle bearings are essential components that allow for smooth rotation in various bike parts, such as the headset, bottom bracket, hubs, pedals, and derailleur. They originated from the early development of cycling technology, where reducing friction between moving parts was key to improving efficiency and performance. Bearings ensure that a bike’s moving components operate with minimal resistance, contributing to a smoother and more efficient ride. The most common type of bearings used in bicycles today are sealed cartridge bearings, due to their durability, ease of maintenance, and effective protection against dirt and moisture, making them ideal for both road and off-road conditions.

In this article, we explain the definition of bicycle bearings, their materials, how these bearings work, the different types based on bearing shapes, bike parts, and related seals, and the lifespan of each type. Then, we dive deep into the different sizes for each type, how to maintain them, and how to choose the right bike bearings for your bike.

Table of Contents

What are bike bearings?

Bike bearings are mechanical components that reduce friction and allow smooth rotational movement between parts like the headset, hubs, bottom brackets, pedals, and derailleur. Originally developed in the late 19th century during the evolution of modern bicycles, bearings became an essential part of cycling, with early versions introduced by companies such as Campagnolo to improve ride efficiency. Typically made from steel or ceramic, bike bearings come in different forms like ball bearings or needle bearings, and their shapes have evolved to offer lower rolling resistance and greater durability. Ceramic bearings, known for their reduced friction and lightweight, are popular in high-performance applications, while steel bearings are valued for their toughness and cost-effectiveness. The primary purpose of bike bearings is to provide a smoother ride, improve mechanical efficiency, and minimize the wear of moving parts, especially under load.

What are bike bearings made from?

Bike bearings are made from materials such as stainless steel, chromium steel, ceramic, and sometimes hybrid combinations of steel and ceramic. These materials are chosen for their specific properties: stainless and chromium steel offer high durability, resistance to wear, and cost-effectiveness, making them suitable for most cycling conditions. Ceramic bearings, on the other hand, are preferred for their low friction, lightweight nature, and corrosion resistance, making them ideal for high-performance applications where reduced rolling resistance and efficiency are crucial.

Steel bearings

Steel bearings have been used in bicycles since the late 19th century, chosen for their strength, durability, and ability to withstand high loads at an affordable cost. Steel is ideal for bearings because it is tough, resists deformation under load, and provides consistent performance, making it highly popular for most cycling applications, including hubs, headsets, bottom brackets, and pedals. Steel bearings are relatively low in cost compared to ceramic options, but they require regular maintenance, such as cleaning and re-greasing, to prevent rust and keep them operating smoothly, especially when exposed to moisture or dirt.

What are the advantages of steel bike bearings?

The advantages of steel bike bearings include high durability, cost-effectiveness, toughness, load-bearing capability, and easy maintenance. These advantages come from the material properties of steel, which are strong, resilient, and widely available, making it suitable for many cycling applications.

  1. High Durability: Steel bearings are resistant to wear and deformation, which makes them ideal for withstanding the constant pressure and rotation involved in cycling.
  2. Cost-Effectiveness: Steel is an affordable material, making steel bearings significantly less expensive than ceramic alternatives, while still providing reliable performance.
  3. Toughness: Steel bearings can handle impacts and rough conditions without easily chipping or cracking, making them suitable for a wide range of bike types, including mountain bikes.
  4. Load-Bearing Capability: The strong nature of steel allows the bearings to handle high loads, making them perfect for areas like the bottom bracket, which bears much of a rider’s weight and pedaling force.
  5. Easy Maintenance: Steel bearings can be easily cleaned, re-greased, and maintained, allowing for extended life and consistent performance with proper care.
What are the disadvantages of steel bike bearings?

The disadvantages of steel bike bearings include susceptibility to rust, higher rolling resistance, weight, frequent maintenance needs, and lower efficiency compared to ceramic bearings. These disadvantages arise from the inherent properties of steel, which makes it prone to corrosion and not as lightweight or efficient as other advanced materials.

  1. Susceptibility to Rust: Steel bearings are prone to corrosion when exposed to moisture, requiring regular greasing and protection to prevent rust from developing.
  2. Higher Rolling Resistance: Steel bearings produce more friction compared to ceramic bearings, which can lead to slightly higher rolling resistance, affecting overall speed and efficiency.
  3. Weight: Steel is heavier compared to ceramic materials, which makes steel bearings less desirable for cyclists looking to reduce overall bike weight, particularly in competitive road cycling.
  4. Frequent Maintenance Needs: Steel bearings require regular cleaning, lubrication, and maintenance to maintain smooth performance, as they are more vulnerable to dirt and moisture.
  5. Lower Efficiency: Compared to ceramic bearings, steel bearings have a slightly rougher surface finish, resulting in less efficient rotation and reduced performance in high-speed or high-efficiency applications.

Ceramic bearings

Ceramic bearings were introduced to cycling in the early 2000s as a high-performance alternative to traditional steel bearings, using ceramic materials like silicon nitride for their low friction, lightweight, and corrosion resistance. Ceramic bearings are popular among competitive cyclists and racers looking for increased efficiency and speed, as their smoother surface and reduced rolling resistance allow for better performance. However, they are significantly more expensive than steel bearings due to the complex manufacturing process. Ceramic bearings require less frequent maintenance compared to steel, as they resist rust and do not require greasing as often. They are commonly used in high-speed, performance-oriented components like wheel hubs, bottom brackets, and jockey wheels where efficiency gains are most beneficial.

What are the advantages of ceramic bike bearings?

The advantages of ceramic bike bearings include low friction, lightweight, corrosion resistance, longer lifespan, and improved efficiency. These advantages are due to the properties of ceramic materials, which offer a smoother surface, reduced density, and enhanced wear resistance, making them ideal for high-performance cycling.

  1. Low Friction: Ceramic bearings have a smoother surface finish compared to steel, resulting in significantly lower rolling resistance, which contributes to a faster and more efficient ride.
  2. Lightweight: Ceramic balls are lighter than steel, which reduces the overall weight of the bearing, making them appealing for cyclists focused on reducing bike weight, particularly in competitive racing.
  3. Corrosion Resistance: Ceramic bearings are highly resistant to rust and moisture, making them suitable for use in all weather conditions without the risk of corrosion that affects steel bearings.
  4. Longer Lifespan: The hardness of ceramic materials means that ceramic bearings wear less over time, resulting in a longer lifespan and less frequent replacement compared to steel bearings.
  5. Improved Efficiency: The reduced rolling resistance and increased precision of ceramic bearings contribute to greater efficiency in power transfer, making them popular in hubs, bottom brackets, and jockey wheels for high-speed performance.
What are the disadvantages of ceramic bike bearings?

The disadvantages of ceramic bike bearings include high cost, fragility, limited impact resistance, specialized maintenance requirements, and diminishing returns for casual riders. These disadvantages arise from the properties of ceramic materials and their specialized nature, which make them better suited for specific high-performance applications rather than general use.

  1. High Cost: Ceramic bearings are significantly more expensive than steel bearings due to the complex and precise manufacturing process required for producing high-quality ceramic materials.
  2. Fragility: Ceramic bearings are more brittle compared to steel and can chip or crack under sudden impact, which makes them less suitable for aggressive off-road or mountain biking where impacts are common.
  3. Limited Impact Resistance: Unlike steel, ceramic bearings cannot deform under high stress, which means they are more likely to be damaged if exposed to rough riding conditions or improper installation.
  4. Specialized Maintenance Requirements: Although ceramic bearings are rust-resistant, they still require specialized maintenance, such as regular inspection and precise lubrication with suitable grease to ensure optimal performance.
  5. Diminishing Returns for Casual Riders: The efficiency gains offered by ceramic bearings are often negligible for casual riders, meaning the high cost and specialized maintenance may not be justified for everyday cycling compared to the performance improvements they provide to competitive cyclists.

Steel vs ceramic bike bearings

Steel and ceramic bike bearings are often compared to determine which is more suitable for different types of cycling, as each has its unique strengths and weaknesses. Steel bearings are widely used due to their affordability, toughness, and reliability, whereas ceramic bearings are favored by competitive cyclists for their reduced friction and increased efficiency. Below is a detailed comparison of these two types of bearings across different features.

FeatureSteel BearingsCeramic Bearings
FrictionHigher friction due to steel-on-steel contact.Lower friction due to smoother ceramic surface.
Rolling ResistanceHigher rolling resistance, reducing efficiency slightly.Lower rolling resistance, providing better efficiency.
Corrosion ResistanceSusceptible to rust, requiring regular greasing for protection.Highly resistant to rust and corrosion, even in wet conditions.
LifespanDurable with proper maintenance but wears over time.Longer lifespan due to harder, wear-resistant material.
EfficiencyGood efficiency but is not as optimized for performance.Highly efficient, especially in high-speed or high-performance applications.
CostSignificantly lower cost, making them accessible for most riders.High cost due to advanced materials and manufacturing processes.
WeightHeavier compared to ceramic, which adds overall bike weight.Lighter, reducing rotational mass and overall bike weight.
MaintenanceRequires regular cleaning and lubrication to prevent rust and wear.Less frequent maintenance is required but needs specialized grease.
Impact ResistanceBetter impact resistance, suitable for rough terrains.More brittle and prone to cracking under high-impact conditions.

Steel vs ceramic bike bearings

Will I notice a difference with ceramic bearings?

Yes, because ceramic bearings have lower friction, reduced rolling resistance, and increased efficiency compared to steel bearings, which can result in noticeable performance gains, especially at high speeds or during long rides. The smoother surface of ceramic bearings allows for a more efficient power transfer, meaning less energy is lost to friction, which is particularly beneficial for competitive cyclists looking to maximize speed and minimize fatigue. However, the difference may be less perceptible for casual riders or those riding at lower speeds, where the efficiency gains may not outweigh the higher cost of ceramic bearings.

Will ceramic bearings make my bike faster?

Yes, because ceramic bearings have lower rolling resistance and reduced friction compared to steel bearings, which allows for more efficient power transfer and less energy loss, resulting in slightly increased speed. The smoother and harder surface of ceramic bearings creates less drag, making them ideal for competitive cycling where even marginal gains in speed and efficiency can make a significant difference, especially over longer distances or during high-speed riding.

Why do bikes have bearings?

Bikes have bearings because they reduce friction between moving parts, allowing smooth and efficient rotational movement in areas like the wheels, bottom brackets, pedals, and headset. Bearings are essential for maintaining the bike’s performance, as they help reduce energy loss, improve efficiency, and ensure that components like the crankset and wheel hubs spin freely with minimal resistance. This reduction in friction not only enhances the overall riding experience by providing a smoother ride but also minimizes wear on crucial parts, extending the lifespan of the bike’s components.

How do bearings on a bike work?

Bearings on a bike work by providing a low-friction interface between rotating components and stationary parts, allowing smooth movement and reducing resistance. Located in key areas such as the headset, hubs, bottom bracket, and pedals, bearings enable these parts to rotate efficiently while carrying the rider’s weight and the forces generated during cycling. In the wheels, bearings help the hub rotate freely around the axle, reducing rolling resistance and allowing the bike to move smoothly. In the bottom bracket, bearings allow the crankset to spin effortlessly, transferring power from the rider’s pedaling to the chain and ultimately to the rear wheel. In the headset, bearings provide smooth steering by facilitating rotation of the handlebars and fork within the head tube. By minimizing friction, bearings contribute to increased efficiency, better power transfer, and a more comfortable ride.

What makes a bearing high-quality?

A bearing is considered high-quality when it has precise tolerances, durable materials, and a well-engineered design that optimizes performance, efficiency, and longevity. High-quality bearings are often made from premium materials such as chromium steel or advanced ceramics, which offer superior hardness, corrosion resistance, and reduced friction. The internal components, including the balls and races, must be manufactured with exact precision to ensure minimal gaps, reducing play and maximizing load distribution. The surface finish of the rolling elements is also a key factor—smoother surfaces result in less rolling resistance and lower friction, which translates to more efficient movement. High-quality bearings typically use seals or shields to protect against dirt and moisture, ensuring consistent performance under various conditions, while their lubrication is specifically formulated to minimize wear and extend the bearing’s lifespan. Overall, the combination of premium materials, precision manufacturing, and effective sealing makes a bearing more reliable, longer-lasting, and capable of handling high-speed and high-load cycling applications.

Bike bearing types

Bike bearing types include bushings, loose ball bearings (cup and cone), cartridge bearings (sealed), and needle bearings, and they can also be categorized based on their location on the bike, such as headset bearings, frame and fork bearings, pedal bearings, hub bearings, bottom bracket bearings, and derailleur bearings. This classification helps distinguish the types based on their shapes and functions as well as where they are used on the bike, as different parts of the bike have unique performance requirements. For example, loose ball bearings are commonly used in hubs and pedals due to their simplicity and ease of adjustment, while sealed cartridge bearings are popular in bottom brackets and headsets because they provide better protection against dirt and moisture, thus reducing maintenance. Needle bearings are used in high-load areas like suspension pivots because of their high load-bearing capacity. This organization allows for a clearer understanding of which bearing type is optimal for specific bike parts, depending on factors such as durability, efficiency, and load capacity.

Bike bearing types based on the shapes

Bike bearing types—bushings, loose ball bearings (cup and cone), cartridge bearings (sealed), and needle bearings—are sorted based on their shapes because each type of bearing has unique structural characteristics that determine its suitability for specific functions, performance, and load-bearing requirements in different parts of the bike. Bushings are simple and cost-effective, loose ball bearings offer adjustability, cartridge bearings are maintenance-friendly and sealed for protection, while needle bearings have a high load capacity; sorting them by shape helps to match the right bearing type to the desired performance traits and application within the bicycle.

Bushings bearings

Bushings bike bearings are plain bearings that consist of a simple cylindrical sleeve that allows rotational or linear movement without the use of rolling elements like balls or rollers. They were one of the earliest forms of bearings, used since the 19th century, particularly in early bicycle designs to provide a basic, low-cost solution for reducing friction. Bushings were initially popular in Europe, where the first bicycles were mass-produced, and they offered a simple and effective means to support moving parts without the need for complex mechanisms. Though they are not as popular in modern bicycles, bushings are still used in specific applications like suspension pivots or inexpensive pedal systems, where low rotational speeds and cost-effectiveness are prioritized over high performance.

Loose ball bearings (cup and cone)

Loose ball bearings, also known as cup and cone bearings, consist of individual steel balls that roll between a “cup,” which is a concave surface fixed in the bike component, and a “cone,” which is an adjustable conical surface attached to an axle, providing smooth rotational movement. This bearing system became widely used in the late 19th and early 20th centuries, especially by iconic bicycle brands such as Shimano and Campagnolo, due to its effectiveness in allowing adjustability and ease of maintenance. Originally developed in Europe, loose ball bearings quickly gained popularity because they could distribute loads evenly, handle both radial and axial forces, and be easily serviced or replaced. These bearings are still popular today, particularly in wheel hubs and pedals, as they offer a balance between performance, cost, and adjustability, making them suitable for both recreational and professional cycling.

Cartridge bearings (sealed)

Cartridge bearings, also known as sealed bearings, are self-contained units that house the bearings and their lubricant within a sealed metal or plastic cartridge, which makes them resistant to dirt and moisture. Cartridge bearings gained popularity in the cycling industry in the late 20th century, primarily in Europe and the United States, as brands like Shimano and Campagnolo began adopting them for their ease of use and low-maintenance advantages. Unlike traditional loose ball bearings, cartridge bearings do not require frequent adjustments or servicing, making them a popular choice for modern bicycles, particularly in high-wear areas such as bottom brackets, wheel hubs, and headsets. Their design allows for easy replacement when worn out, making them ideal for cyclists seeking reliability and reduced maintenance while enjoying smoother rotation and enhanced durability. The sealed nature of these bearings helps protect them from dirt and water, making them highly popular in road, gravel, and mountain bikes, where exposure to the elements is a significant concern.

How efficient are sealed bearings?

Sealed bearings are highly efficient because they minimize friction and prevent contaminants like dirt and moisture from reaching the rolling elements, which helps maintain smooth operation over time. The efficiency of sealed bearings comes from their enclosed design, which keeps the lubricant inside the cartridge while preventing debris from interfering with the bearing surfaces, reducing the risk of wear and friction buildup. Additionally, the smooth surface finish of the rolling elements and races in a sealed bearing allows for low rolling resistance, contributing to improved energy transfer in cycling applications. The seals help maintain optimal conditions for the bearings to rotate freely without the need for frequent maintenance, which further supports consistent performance and efficiency in components like wheel hubs, bottom brackets, and headsets.

Needle bearings (roller)

Needle bearings, also known as roller bearings, are a type of bearing that uses long, thin cylindrical rollers instead of balls to distribute loads more evenly across a greater surface area, reducing friction and allowing for higher load capacities. Needle bearings were introduced in the early 20th century, primarily in the automotive industry, before making their way into cycling applications, especially for high-load components. Their adoption in bicycles started to become more common in Europe, as brands and manufacturers sought to develop systems that could handle higher forces without compromising performance. These bearings are commonly used in suspension pivots and other high-stress areas of mountain bikes, where their design helps distribute forces efficiently, making them ideal for demanding conditions. Although not as popular as ball bearings in most cycling applications, needle bearings are highly valued for their durability and ability to handle the heavy loads that are often encountered in full-suspension mountain biking.

Bike bearing types based on the bike parts

Bike bearing types are sorted based on bike parts such as headset bearings, frame and fork bearings, pedal bearings, hub bearings, bottom bracket bearings, and derailleur bearings because each part of the bike requires specific bearing characteristics to optimize its performance. Sorting bearings by bike parts allows for the selection of the most suitable bearing type based on factors like load, rotation speed, friction requirements, and exposure to the elements, ensuring that each component—whether it’s for steering, drivetrain efficiency, or wheel rotation—performs optimally under its specific conditions.

Bike headset bearings

Bike headset bearings are the components that allow the smooth rotation of the handlebars and fork, enabling steering control of the bicycle. Headset bearings have been used since the introduction of modern bicycles in the late 19th century, originally designed in Europe by early bike manufacturers to improve the efficiency and reliability of steering systems. Traditional headset bearings were loose ball bearings housed in cups integrated into the head tube, providing the necessary support for rotating the front end. Over time, sealed cartridge bearings became popular for headsets, offering easier maintenance and improved protection against dirt and moisture. Headset bearings are critical for the overall handling and control of the bike, and they are used in all types of bicycles—road, mountain, and hybrid—making them a fundamental component in the cycling industry. Their popularity has increased with the development of integrated headsets, which help reduce weight and enhance the aesthetic appeal of modern bike frames.

Bike frame and fork bearings

The bike frame and fork bearings are bearings located in areas where the frame and fork require movement, most commonly in full-suspension mountain bikes to facilitate the articulation of suspension linkages. These bearings were introduced with the rise of full-suspension mountain bikes in the late 20th century, primarily developed by brands like Specialized, Trek, and Giant, who aimed to enhance off-road performance and control. These bearings are typically needle bearings or sealed cartridge bearings, chosen for their ability to handle high loads and reduce friction at pivot points. Frame and fork bearings play a crucial role in maintaining smooth suspension movement, providing consistent traction, and ensuring optimal energy transfer when riding on rough terrain. Their use has become popular in all types of mountain bikes, especially in enduro, trail, and downhill disciplines, where efficient and responsive suspension systems are essential for performance.

Bike pedal bearings

Bike pedal bearings are the components inside the pedal that allow it to rotate smoothly around the spindle, providing efficient power transfer from the rider’s foot to the crankset. Pedal bearings have been used since the invention of the bicycle in the late 19th century, initially utilizing loose ball bearings to allow the pedals to spin freely, thereby improving pedaling efficiency. Originally developed in Europe, early pedals were simple, with basic ball bearings, but over time, advancements by brands such as Shimano and Look led to the introduction of sealed cartridge bearings, which improved the durability and ease of maintenance of pedals. Today, pedal bearings are used in both flat and clipless pedals across all types of bikes, including road, mountain, and commuter bikes. They are highly popular due to their essential role in ensuring smooth pedaling, minimizing friction, and allowing riders to transfer power efficiently during cycling.

Bike hub bearings

Bike hub bearings are the components that allow the smooth rotation of the wheel hubs around the axle, providing efficient rolling performance. Hub bearings have been used since the early development of bicycles in the late 19th century, starting with loose ball bearings to reduce friction and improve wheel efficiency. They were initially developed by early cycling innovators in Europe, and brands like Campagnolo and Shimano played key roles in improving the hub-bearing design. Traditionally, cup and cone bearings with loose steel balls were used in hubs, but sealed cartridge bearings later became popular for their ease of maintenance and enhanced protection against dirt and moisture. Hub bearings are found in both front and rear wheels, and they are crucial for maintaining smooth rolling, minimizing drag, and providing durability under various conditions. They are highly popular in all types of cycling—from road to mountain biking—since their quality and efficiency directly impact the overall performance and feel of the bike.

Bike bottom bracket bearings

Bike bottom bracket bearings are the bearings that allow the crankset to rotate smoothly within the bottom bracket shell, enabling efficient power transfer from the rider’s pedaling to the drivetrain. Bottom bracket bearings have been part of bicycle design since the late 19th century, originally employing loose ball bearings housed in cups to facilitate rotation. Developed initially in Europe, early versions were made by manufacturers like BSA (Birmingham Small Arms) to enhance pedaling efficiency and reliability. Over time, innovations by major cycling brands like Shimano, Campagnolo, and SRAM led to the development of sealed cartridge bottom bracket bearings, which offer greater durability, reduced maintenance, and protection from dirt and moisture. Bottom bracket bearings are crucial for all types of bikes—road, mountain, and gravel—as they directly affect the smoothness of pedaling and the efficiency of power transfer. Today, they are widely popular due to their reliability, with most modern bikes incorporating sealed bearings to maximize performance and minimize maintenance.

Bike derailleur bearings

Bike derailleur bearings are the small bearings found in the pulley wheels (jockey wheels) of the derailleur, which allow these wheels to spin smoothly and help guide the chain during shifting. Derailleur bearings were introduced alongside the first rear derailleurs in the early 20th century, primarily in Europe by cycling innovators such as Campagnolo and Simplex, who sought to improve the efficiency and reliability of gear shifting. Initially, bushings were used in pulley wheels, but as the need for smoother, more precise shifting grew, loose ball bearings and eventually sealed cartridge bearings became common. Today, derailleur bearings are used in almost all modern rear derailleurs, both in road and mountain biking, contributing to smoother shifting performance, reduced friction, and increased drivetrain efficiency. With the increasing focus on high-performance drivetrains, high-quality sealed bearings in derailleur pulleys are highly popular for their ability to improve the smoothness and precision of shifting under varying conditions.

How many bearings are on each side of a bicycle hub?

There are typically two bearings on each side of a bicycle hub, totaling four bearings per hub. In some cases, especially in high-end or performance hubs, the number of bearings may vary—certain rear hubs use three bearings on the drive side to handle the additional forces from pedaling, while some front hubs may use only a single larger bearing on each side for simplicity and weight reduction. The number of bearings depends on the hub design and intended load capacity, with more bearings providing increased stability and durability, especially for hubs that experience higher forces, such as those on mountain bikes or bikes used in heavy-duty conditions.

What types of seals are there on bicycle bearings?

On bicycle bearings, there are primarily two types of seals: rubber seals (contact seals) and metal shields (non-contact seals). Rubber seals are used to provide a tight fit that prevents dirt, moisture, and contaminants from entering the bearing, offering optimal protection, especially in wet or muddy conditions. Metal shields, on the other hand, do not contact the inner race of the bearing and provide moderate protection while minimizing friction, which is ideal for applications requiring low resistance, such as road cycling. Additionally, there are labyrinth seals, which use a series of narrow passages to block contaminants, providing a balance of protection and low drag. The choice of seal type depends on the application—rubber seals are often used for bearings in bottom brackets and hubs for added durability, while metal shields are more common in bearings where reduced friction is prioritized.

Bike bearing sizes

Bike bearing sizes vary depending on the type and application, with bushings typically being sized to fit their specific mounting point, loose ball bearings usually around 3/16″ or 1/4″ in diameter, cartridge bearings commonly available in sizes such as 6805 (25x37x7 mm) or 6902 (15x28x7 mm), and needle bearings often sized according to the load they need to handle, such as 15x20x12 mm. These sizes are chosen based on the requirements for load handling, rotational speed, and the specific component in which they are used. Bearings are designed to fit perfectly into their respective components to ensure optimal performance, stability, and efficiency while managing the specific load requirements of each part of the bike.

Below is a comparison of the sizes of different types of bike bearings.

Type of BearingCommon SizesPurpose of Size
BushingsVaries (e.g., 20×15 mm)Sized to fit pivot points with low rotational speed, focusing on durability and ease of maintenance.
Loose Ball Bearings3/16″, 1/4″Standard sizes to fit hubs, headsets, and bottom brackets, balancing load handling and adjustability.
Cartridge Bearings6805 (25x37x7 mm), 6902 (15x28x7 mm)Sealed bearings for hubs, bottom brackets, and headsets, were chosen for durability, load capacity, and easy replacement.
Radial vs Angular Cartridge BearingsRadial: 6902 (15x28x7 mm), Angular: 7202 (15x35x11 mm)Radial bearings for high-speed applications with low axial loads; angular bearings for components with combined radial and axial forces, like headsets.
Needle Bearings15x20x12 mmUsed in high-load areas like suspension pivots, offering better load distribution across a larger contact area.

Bike bearing sizes

What are the common wheel bearing sizes?

The common wheel bearing sizes for bicycle hubs are 6000 (10x26x8 mm), 6802 (15x24x5 mm), 6804 (20x32x7 mm), and 6902 (15x28x7 mm). These sizes are selected to balance durability, load capacity, and the ability to minimize friction while fitting precisely into the hub shell and axle. Bearings like the 6802 and 6902 are popular because they are compact but offer sufficient load-bearing capacity for both radial and axial forces experienced in cycling, making them suitable for the demands of road, mountain, and gravel bike wheels. Additionally, the standard sizing allows for easy replacement, maintenance, and compatibility across a wide range of hubs and wheelsets.

Bike bearing weight

Bike bearing weight typically ranges from 10 grams to 40 grams per bearing, depending on the type and material. Steel bearings are generally heavier, ranging from 20 to 40 grams due to the density of steel, which provides durability and load-bearing strength. In contrast, ceramic bearings can weigh as little as 10 to 25 grams because of the lighter weight of ceramic materials, which helps reduce rotational mass and improve performance. The weight of a bearing is influenced by factors such as its size, material, and type (e.g., loose ball, sealed cartridge, or needle), with larger bearings and those designed for higher load capacities being heavier due to increased material volume and structural requirements.

How to measure bike bearings?

To measure bike bearings, use a digital caliper to accurately determine the bearing’s inner diameter (ID), outer diameter (OD), and width. Start by removing the bearing from the component, then use the caliper to measure the inner diameter by placing the tips of the caliper inside the center hole of the bearing. Next, measure the outer diameter by placing the caliper around the outer edge of the bearing, and finally measure the width by positioning the caliper across the side of the bearing. Accurate measurements are important to ensure proper fit when selecting replacements, and using a digital caliper allows for precise readings down to tenths or hundredths of a millimeter.

Are all bike bearings the same size?

No, because bike bearings come in various sizes depending on the component they are used in and the specific requirements of each application. Different parts of a bike, such as hubs, bottom brackets, headsets, and pedals, have unique load, rotational speed, and size constraints, which means that bearings are designed in different dimensions to fit properly and function efficiently in each part. For example, headset bearings are often larger to handle the forces of steering, while hub bearings are more compact to minimize friction and ensure smooth wheel rotation.

How long do bike bearings last?

Bike bearings typically last between 1,500 to 5,000 miles (2,400 to 8,000 kilometers), depending on factors such as material, type, riding conditions, and maintenance. The lifespan of a bearing is affected by its material—ceramic bearings generally last longer due to their harder surface and resistance to corrosion, whereas steel bearings are more prone to wear and rust. The design also plays a role, with sealed cartridge bearings often outlasting loose ball bearings because they are better protected from contaminants like dirt and moisture. Regular maintenance, such as cleaning and re-greasing, can also extend the lifespan of the bearings, while harsh riding conditions, such as wet or muddy environments, can accelerate wear and reduce their longevity.

How to maintain bike bearings?

To maintain bike bearings, you need to regularly clean, inspect, and re-grease them to ensure smooth performance and prevent wear. Start by removing the bearing from the bike component (such as the hub, headset, or bottom bracket) using the appropriate tools like cone wrenches or a bearing puller. Clean the bearings thoroughly using a degreaser and a clean cloth to remove any old grease, dirt, and grime. Once cleaned, inspect the bearings for signs of wear, such as pitting or rough spots, and replace them if necessary. Apply fresh bearing grease evenly using a grease gun or your finger, ensuring the bearing surfaces are well-coated for smooth rotation. After greasing, reassemble the components, making sure the bearings are properly seated and torqued to the recommended specifications. Proper maintenance helps extend the lifespan of the bearings and keeps the bike performing efficiently, especially in challenging riding conditions.

How to replace bike bearings?

To replace bike bearings, start by removing the component, such as a hub, bottom bracket, or headset, from the bike using the appropriate tools like cone wrenches or a bottom bracket tool. Disassemble the component to access the bearings, using a bearing puller or punch to carefully remove the old bearings. Clean the bearing seats thoroughly using a degreaser and a clean cloth to ensure that no dirt or old grease remains. Inspect the area for any damage before installing new bearings. Press in the new bearings using a bearing press tool to avoid damaging them, ensuring they are seated evenly and correctly. Reassemble the component, making sure all parts are aligned and torqued according to manufacturer specifications. Properly replacing bearings with the right tools and careful alignment will help maintain the efficiency and lifespan of the component, ensuring smooth operation during riding.

Can bearings in a bike wheel be replaced?

Yes, because bearings in a bike wheel are designed to be replaceable to maintain smooth performance and extend the life of the hub, but the process requires specific tools, such as bearing pullers and presses, and care must be taken to avoid damaging the hub or the new bearings during installation. Both loose ball bearings and sealed cartridge bearings can be replaced, with cartridge bearings being easier to swap out, while cup-and-cone systems may require more careful handling and adjustment.

How to change bearings on a bike crank?

To change bearings on a bike crank, first remove the crank arms from the bike using a crank puller or Allen wrench, depending on the crank system. Next, remove the bottom bracket from the frame using a bottom bracket removal tool. Once the bottom bracket is out, use a bearing press or a bearing puller to carefully remove the old bearings from the bottom bracket shell. Clean the inside of the shell using a degreaser and a clean cloth to ensure no dirt or grime remains. Press the new bearings into place using a bearing press, making sure they are seated evenly and securely without causing damage. Reinstall the bottom bracket into the bike frame and torque it to the manufacturer’s recommended specifications, then reinstall the crank arms. Changing crank bearings helps maintain efficient power transfer and smooth pedaling, ensuring the drivetrain continues to perform optimally.

How to change headset bearings on a road bike?

To change headset bearings on a road bike, start by removing the handlebars and stem using an Allen wrench to gain access to the headset. Next, remove the top cap and loosen the headset preload bolt, then remove the spacers and the stem entirely. Carefully slide the fork out of the head tube, taking care to support it to prevent any damage. Once the fork is out, use a bearing removal tool or gently tap the old bearings out of the head tube using a soft mallet or punch. Clean the bearing cups and head tube using a degreaser to remove any dirt and old grease. Apply fresh grease to the bearing seats, then insert the new headset bearings—ensuring they are the correct type (either sealed cartridge or loose ball bearings in a race) and properly oriented. Slide the fork back into the head tube, replace the spacers, reinstall the stem, and tighten the preload bolt to eliminate any play while maintaining smooth steering. Reattach the top cap and handlebars, and ensure everything is torqued according to the manufacturer’s specifications. Changing headset bearings keeps the steering smooth and responsive, reducing friction and improving overall control.

How to change pedal bearings on a mountain bike?

To change pedal bearings on a mountain bike, start by removing the pedals from the crank arms using a pedal wrench or Allen key, depending on the pedal type. Once removed, use a small flat-head screwdriver or pick to carefully pry off the end cap from the pedal body to expose the axle. Use an appropriately sized wrench or socket to loosen the axle nut or bolt and slide the axle out of the pedal body. Once the axle is removed, extract the old bearings—either using a bearing puller for cartridge bearings or by simply tipping the pedal body if they are loose ball bearings. Clean all components thoroughly using a degreaser to remove old grease, dirt, and contaminants. If replacing loose ball bearings, carefully insert new bearings into the bearing race, making sure to use fresh bearing grease to hold them in place. For sealed cartridge bearings, use a bearing press to install the new cartridge. Reassemble the axle into the pedal body, tighten the axle nut or bolt to the manufacturer’s specifications, and reattach the end cap. Finally, reinstall the pedals onto the crank arms, ensuring they are torqued properly. Changing pedal bearings helps maintain smooth pedal rotation and efficient power transfer while riding.

What type of grease for bike bearings?

Grease for bike bearings should be high-quality, waterproof, and suitable for high-pressure environments to ensure smooth operation and protection against contaminants. The most commonly used types are lithium-based grease, marine grease, and ceramic grease. Lithium-based grease is popular because it provides excellent lubrication, and corrosion resistance, and can handle high loads, making it ideal for most bike applications such as wheel hubs, bottom brackets, and headsets. Marine grease is another great option, especially for mountain bikes, as it offers superior resistance to moisture, making it suitable for wet and muddy conditions. Ceramic grease, which contains ceramic particles, is used for high-performance applications due to its low friction and high durability, commonly applied in ceramic bearings for optimal efficiency. Choosing the right type of grease depends on the riding conditions and bearing type, but all should be waterproof, able to resist washout and provide long-lasting lubrication to maintain bearing performance.

How to grease bike bearings?

To grease bike bearings, first remove the component containing the bearings, such as a wheel hub, bottom bracket, or headset, using the appropriate tools like wrenches or a bearing puller. Disassemble the component to access the bearings, and thoroughly clean them using a degreaser to remove old grease, dirt, and grime. For loose ball bearings, use a small brush or cloth to clean the bearing race and cups. Once clean, apply fresh waterproof grease to the bearings using a grease gun or your finger, ensuring an even layer of grease covers all the rolling surfaces. For sealed cartridge bearings, gently pry off the rubber seal, clean the exposed bearing area, and apply fresh grease before reinstalling the seal. Reassemble the component, making sure all parts are correctly aligned, and tighten everything according to the manufacturer’s torque specifications. Greasing the bearings reduces friction, prevents wear, and helps keep out contaminants, ensuring smooth performance and a longer bearing lifespan.

How to lubricate bike wheel bearings?

To lubricate bike wheel bearings, first, remove the wheel from the bike and use cone wrenches to loosen the locknut and cone, allowing you to access the bearings inside the hub. Carefully remove the axle, make sure to collect any loose ball bearings that might fall out, and clean the bearings and bearing races thoroughly using a degreaser to remove any old grease, dirt, and contaminants. Once clean, apply fresh waterproof grease to the bearing races using a grease gun or your finger, ensuring an even layer is applied. Place the bearings back into their races, and make sure they are securely coated with grease to ensure smooth movement. Carefully reinsert the axle, adjusting the cone and locknut to eliminate any play while ensuring the hub spins freely. Reassemble and reinstall the wheel onto the bike, checking that the wheel spins smoothly and without any wobbling. Lubricating wheel bearings helps minimize friction, ensures smooth wheel rotation, and extends the life of the bearings.

Can I use bike chain lube on the bearings?

No, because bike chain lube is formulated for use on chains, which requires a thinner, penetrating lubricant to reduce friction while not attracting too much dirt. Bearings need a thicker grease that stays in place to reduce friction under load and protect against contaminants, but chain lube is not thick enough to provide the needed protection and longevity.

Can external cartridge bike bearings be lubed?

Yes, because external cartridge bearings can sometimes be accessed by removing the seal, allowing you to apply fresh grease, but this process can be delicate, and improper handling can damage the bearing seal or introduce contaminants, making it necessary to proceed with caution.

Can I put car grease into bike bearings?

Yes, because car grease can provide good lubrication and protection, as it is designed for high-load automotive applications, but it can be too heavy and sticky for bike bearings, which could increase rolling resistance and reduce efficiency, making bike-specific grease a better choice for optimal performance.

What is the typical pricing to regrease bearings in the bike hub?

The typical cost to regrease bearings in a bike hub ranges from $15 to USD 25 per hub. This price includes labor for disassembling the hub, cleaning, applying fresh grease, and reassembling. If the bearings are worn and need replacement, the total cost may increase by an additional $10 to USD 20 for parts, depending on the bearing type and quality. The most significant expense in this service is the labor involved, as it requires time and expertise to properly service the hub and ensure optimal performance.

How to clean bike bearings?

To clean bike bearings, first remove the component containing the bearings, such as a wheel hub, bottom bracket, or headset, using the appropriate tools like cone wrenches or a bearing puller. Once you have access to the bearings, remove them from the bearing race or cartridge. Use a degreaser or a solvent to thoroughly clean the bearings, races, and bearing cups, ensuring that all old grease, dirt, and contaminants are removed. You can use a small brush or an old toothbrush to scrub away stubborn grime. After cleaning, rinse the bearings and allow them to dry completely, using compressed air to speed up the drying process if available. Inspect the bearings for wear or damage—replace any that are pitted or rough. Once the bearings are clean and dry, reapply fresh waterproof grease to provide lubrication before reinstalling them in the component. Cleaning the bearings thoroughly ensures optimal performance, reduces friction, and extends the life of both the bearings and the components.

Bike bearings brands

Bike bearings are essential components in ensuring the smooth operation and performance of various bicycle parts, such as hubs, headsets, and bottom brackets. The industry has a wide range of bearing brands, each offering specialized solutions to meet different cycling needs, from affordability and durability to low-friction performance for competitive cycling. Below is a table of well-known bike-bearing brands, including information about their origins, special features, and year of establishment.

BrandCountry/RegionEstablishedSpecial Features
CeramicSpeedDenmark2004High-quality ceramic bearings are known for ultra-low friction and performance.
Enduro BearingsUSA1996Durable, high-performance bearings with MAX-type designs for extra load capacity.
SKFSweden1907Industry-leading steel and hybrid ceramic bearings with excellent reliability.
FSA (Full Speed Ahead)Taiwan, China1993Offers a range of high-quality headset and bottom bracket bearings for road and MTB.
Hope TechnologyUK1989Stainless steel sealed bearings are known for durability in extreme conditions.
DT SwissSwitzerland1994High-quality cartridge bearings are used in hubs and suspension components.
Chris KingUSA1976Precision-engineered bearings with a focus on longevity and serviceability.
NSKJapan1916High-quality bearings with a reputation for durability and smooth performance.
Wheels ManufacturingUSA1988Replacement bearings for bottom brackets, known for affordability and quality.
Kogel BearingsUSA2013Specializes in ceramic bearings with a focus on low drag and improved efficiency.

Bike bearings brands

Bike bearing manufacturers

Bike bearings are essential components in ensuring the smooth operation and performance of various bicycle parts, such as hubs, headsets, and bottom brackets. The industry has a wide range of bearing brands, each offering specialized solutions to meet different cycling needs, from affordability and durability to low-friction performance for competitive cycling. Below is a table of well-known bike-bearing brands, including information about their origins, special features, and year of establishment.

BrandCountry/RegionEstablishedSpecial Features
CeramicSpeedDenmark2004High-quality ceramic bearings are known for ultra-low friction and performance.
Enduro BearingsUSA1996Durable, high-performance bearings with MAX-type designs for extra load capacity.
SKFSweden1907Industry-leading steel and hybrid ceramic bearings with excellent reliability.
FSA (Full Speed Ahead)Taiwan, China1993Offers a range of high-quality headset and bottom bracket bearings for road and MTB.
Hope TechnologyUK1989Stainless steel sealed bearings are known for durability in extreme conditions.
DT SwissSwitzerland1994High-quality cartridge bearings are used in hubs and suspension components.
Chris KingUSA1976Precision-engineered bearings with a focus on longevity and serviceability.
NSKJapan1916High-quality bearings with a reputation for durability and smooth performance.
Wheels ManufacturingUSA1988Replacement bearings for bottom brackets, known for affordability and quality.
Kogel BearingsUSA2013Specializes in ceramic bearings with a focus on low drag and improved efficiency.

Bike bearing manufacturers