Bicycle bearings: everything you need to know
Bearings are often overlooked components that actually bring life to your bike. Without bearings, you can’t steer, roll, pedal, or have a functioning drivetrain. They allow the wheels to spin freely and provide a smooth and comfortable ride.
The most common types of bicycle bearings are cartridge bearings, cup bearings, and loose ball bearings. Each type has its advantages and disadvantages, so it’s important to choose the right type of bearing for your bike.
In this guide, we’ll take a look at the different types of bearings commonly used on bicycles. It also discusses why one bearing is better than another and how to maintain it.
The different types of bearings used on a bike
There are many different types of bearings used on bicycles. Deep groove ball bearings are used in the wheels and pedals as well as the bottom bracket and headset. Needle bearings are primarily used in hubs and bottom brackets, as well as headsets. Cartridge bearings are used in brakes and derailleurs. Here we explain how each bearing is different.
Bushing, sometimes referred to as a bush or sleeve bearing, is a type of simple bearing commonly used in shock mounts, pulley wheels, and shifters. This device works by forming a sleeve between two surfaces for decreased friction and guided movement.
Loose ball bearings (also known as ‘cup and cone bearings)
Loose ball bearings are used on many entry-level bikes, and although traditional in design, can feature superior performance when tuned optimally. These components can be found in hubs, bottom brackets, and headsets. At the high end, most brands have opted to use tapered bearings instead of loose bearings. However, some companies still utilize loose ball bearings for their pedals.
Loose ball bearings utilize corner contact points but often require maintenance to ensure they perform at maximum efficiency. To keep these individual parts separate and secure, retainers or ‘cages’ made of pressed steel are used – hence the name ‘cage bearing’.
Cartridge bearings are the most widely used type of bearing, apart from the cheapest ones. As manufacturing technology has become more advanced and tolerances in hub, frame, and component bores have gotten better, their popularity has grown because of their precision.
A typical cartridge bearing is a single-piece unit that usually gets pressed into the bearing bore, composed of an outer race, an inner race, ball bearings, a cage/retainer to keep the bearings in place, and two seals on either face to keep out dirt. Unfortunately, these bearings can’t be adjusted or disassembled.
Needle roller bearings, which are also known as roller bearings, have largely been replaced in the cycling industry by cheaper and more reliable technologies such as multiple rows of cartridge bearings. Needle bearings feature cylindrical rollers instead of ball bearings and can provide exceptionally smooth movements and stable platforms when used correctly. However, if not mated properly, they may fatigue quickly, thereby diminishing their potential benefits. Therefore, it is important to ensure proper mating surfaces with needle-bearing applications to maximize performance levels.
Radial vs angular cartridge
The choice between radial and angular cartridge bearings depends on the specific application and system load requirements. If the system is primarily loaded in the radial direction, radial cartridge bearings would be more suitable. If the system bears radial and axial loads at the same time and emphasizes axial loads, angle clip bearings will be more suitable.
A radial bearing is a rolling bearing designed to support radial loads, which are loads acting perpendicular to the shaft or axis of the bearing. They are commonly used in a wide range of industrial applications including machinery, automotive systems, and power transmission equipment.
Radial bearings usually consist of an inner and outer ring separated by a number of rolling elements such as balls or rollers. The rolling elements are held in place by cages or separators, keeping them evenly spaced and preventing them from touching each other.
When a radial load is applied to the bearing, the rolling elements roll along the raceway and distribute the load evenly on the bearing. This helps reduce friction and wear, extending the life and performance of the bearing.
There are many different types of radial bearings, including ball bearings, roller bearings, and needle bearings. The choice of bearing type depends on the specific application and the load and speed requirements of the system.
Angular contact bearings
Angular contact bearings are a type of rolling bearings designed to support radial and axial loads. They are typically used in high-speed applications that require precise control of rotary motion, such as machine tools and automotive systems.
Angular contact bearings usually consist of an inner and outer ring separated by a number of rolling elements such as balls or rollers. The rolling elements are held in place by cages or separators, keeping them evenly spaced and preventing them from touching each other.
The raceways of angular contact bearings are at an angle to each other, called the contact angle, and can range from 15 degrees to 40 degrees or more, depending on the specific design of the bearing.
When an axial load is applied to an angular contact bearing, the rolling elements are forced to slide along the raceways, creating a force perpendicular to the axis of rotation. This force can be used to control the rotational motion of the shaft, allowing precise control and high-speed operation.
What makes a high-quality bearing?
There are many factors to consider when selecting a quality bearing. The first is load-carrying capacity, which is the maximum weight the bearing can bear. This is followed by the maximum speed, which is the highest speed at which the bearing can run trouble-free. Other factors to consider include abrasion resistance, resistance to sudden shocks, and the ability to operate in extreme temperatures.
What are bearings made from?
Bearings are made from a variety of materials, but the most common material is steel. Other materials that are used to make bearings include brass, bronze, and ceramic. The material that is used to make a bearing will depend on the application it will be used for. For example, bearings that will be used in high-speed applications will be made from materials that can withstand high speeds and friction.
How to maintain bearings?
Bearing maintenance is critical to keeping machines running smoothly and reducing wear. There are a few simple things you can do on a regular basis to extend the life of your bearings and keep them in good shape.
Here are some tips for bearing maintenance:
Keep bearings clean and free of debris.
Lubricate the bearings regularly.
Check the bearings for signs of wear or damage.
Replace bearings when they show signs of wear or damage.
By following these tips, you can keep your bearings in good condition and extend their life.
Also, if you’re using angular contact bearings, the seals are a different color for a reason – black seals are meant to face the centerline, while red should face out.
In summary, bicycle bearings play a vital role in the performance and longevity of bicycle components. When selecting a bearing, it is important to consider factors such as load capacity, friction, and durability, as well as the specific requirements of your bike and riding style. Regular cleaning and lubrication will help extend bearing life, while proper mounting and adjustment will ensure optimum performance.