Wheelchair Bearings: A Guide to Maintenance, Replacement & Installation
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Wheelchair Bearings: A Guide to Maintenance, Replacement & Installation
Bearings are a small component of a manual wheelchair, but they can have a large impact on how smoothly your chair rolls.
Most manual wheelchairs use bearings in several areas, including the rear wheel hubs, front casters and caster forks. Over time, these bearings are exposed to water, dirt, hair and general wear. As their condition deteriorates, you may notice increased resistance, noise or unwanted movement in your wheels and casters.
The good news is that wheelchair bearings are generally replaceable and, with the correct bearings and tools, many mechanically confident wheelchair users can carry out basic bearing replacement themselves.
In this guide, we'll look at where wheelchair bearings are used, how to recognise worn bearings, common bearing sizes and how the correct removal and installation tools can make replacing them considerably easier.
Where Are Bearings Found on a Manual Wheelchair?
Although the exact configuration varies between wheelchair models, bearings are commonly found in three main areas.
Rear Wheel Bearings
Most removable manual wheelchair rear wheels contain bearings inside the wheel hub. Typically, there is a bearing on either side of the hub, with the quick-release axle passing through the centre.
These bearings allow the rear wheel to rotate freely around the axle.
Rear wheel bearing dimensions also need to correspond with the axle system being used. For example, many manual wheelchair wheels using a 1/2" quick-release axle use R8 bearings, while wheels designed around 12mm axles generally require a different bearing.
Front Caster Bearings
Front caster wheels usually contain a bearing on either side of the caster.
Because casters are positioned close to the ground, they can be particularly exposed to water, dirt, hair and other debris during everyday use. Hair and fibres can also accumulate around the caster axle and bearing area.
Caster Fork Bearings
Bearings are also commonly used where the caster fork rotates in relation to the wheelchair frame.
These allow the fork to swivel as the wheelchair changes direction. Depending on the wheelchair and fork design, the bearing arrangement and size can vary considerably.
Some wheelchair components and accessories may contain additional bearings, so you should always check the specifications for your particular wheelchair before ordering replacements.
How Do You Know When Wheelchair Bearings Need Replacing?
There isn't necessarily a fixed replacement interval for wheelchair bearings. How quickly they wear depends on the wheelchair, bearing quality, environment and how the chair is used.
Instead, bearings should form part of regular wheelchair inspection and maintenance.
Signs that a bearing may require attention include:
- Grinding, scraping or unusual noises while the wheel rotates
- A rough or gritty feeling when rotating the wheel by hand
- Increased resistance or reduced free-spinning
- Excessive movement or play
- Visible corrosion or contamination
- A bearing that has seized or no longer rotates correctly
Water is particularly worth considering. Even sealed bearings can eventually be affected by repeated exposure to moisture, and wheelchair users who regularly travel through rain, wet paths or other harsh environments may need to inspect their bearings more frequently.
Front caster areas can also collect hair and other debris, so not every rolling problem necessarily means the bearing itself has failed. Cleaning the caster and axle area is a sensible first step when investigating a problem.
What's Inside a Wheelchair Bearing?
Most wheelchair bearings are ball bearings consisting of several basic components.
These include an inner race, outer race, a series of steel balls, a cage or retainer that keeps the balls correctly positioned, lubrication, and seals or shields on either side.
The inner and outer races rotate relative to each other while the balls reduce friction between them.
Many wheelchair replacement bearings are sealed bearings. You may therefore see bearing codes ending in 2RS. This generally indicates that the bearing has rubber seals on both sides, helping retain lubricant while reducing the entry of water and contaminants.
For wheelchair applications, sealing and suitable lubrication are particularly useful because wheelchairs are regularly exposed to environments that aren't especially friendly to bearings.
Understanding Wheelchair Bearing Sizes
You don't need to be a bearing expert to identify a replacement, but it helps to understand how bearings are measured.
The three important measurements are:
Inside Diameter (ID) × Outside Diameter (OD) × Width
For example, an R8-2RS wheelchair bearing measures:
1/2" ID × 1-1/8" OD × 5/16" wide
The inside diameter is particularly important because this is the opening through which the axle or corresponding component passes.
Another bearing commonly found in wheelchair applications is the R6, which measures:
3/8" ID × 7/8" OD × 9/32" wide
Metric bearings such as the 608 are also widely used, particularly in front casters.
However, these examples shouldn't be treated as universal. Wheelchair manufacturers use different bearing sizes across different chairs, wheels, forks and model years.
Always confirm the bearing fitted to your particular component before ordering a replacement.
Do Wheelchair Bearings Need to Be Serviced Every Year?
Annual inspection is a useful general maintenance practice, but that doesn't mean every bearing needs replacing every 12 months.
A wheelchair that spends considerable time outdoors or around water may require more frequent attention than one predominantly used indoors. Bearing condition is more important than simply replacing them according to the calendar.
Routine maintenance can include checking for contamination, removing hair and debris from caster areas, checking for play or roughness and replacing bearings that are no longer operating correctly.
In some cases bearings can be cleaned and repacked with suitable bearing grease. However, given the relatively low cost of many wheelchair bearings and the work involved in removing and servicing a sealed bearing, replacement can often be the more practical option once a bearing has noticeably deteriorated.
Removing Wheelchair Bearings
Getting an old bearing out can often be one of the more difficult parts of the job.
Wheelchair bearings can sit inside relatively small or recessed hubs, casters and fork assemblies. This can make conventional automotive bearing tools too large, while trying to improvise with screwdrivers, punches or other unsuitable tools can increase the risk of damaging the surrounding component.
A purpose-designed blind bearing puller or extractor works by gripping the bearing through its inside diameter. The bearing can then be removed from the component using the appropriate removal tool.
This is particularly useful with recessed wheelchair wheel hubs and other components where access behind the bearing is limited.
Installing New Wheelchair Bearings
Installing the replacement bearing correctly is just as important as removing the old one.
A bearing needs to enter its seat straight and evenly. Trying to hammer a new bearing into position unevenly can damage the bearing or the wheel, caster or fork into which it is being installed.
A bearing press or correctly sized bearing installer allows controlled, even pressure to be applied while the bearing is seated.
When pressing a bearing into a hub or housing, force should generally be applied to the outer race rather than transferring the installation load through the inner race and ball bearings.
Why Use Wheelchair-Specific Bearing Tools?
Wheelchair bearings are relatively small, and many are fitted into lightweight aluminium hubs, forks and caster components where avoiding damage is particularly important.
Purpose-designed wheelchair bearing tools can include:
- Blind bearing pullers or extractors for removing bearings from recessed components
- Pin punches or removal tools used with compatible extractors
- Bearing presses and installers for seating replacement bearings straight and evenly
- Bearing removal and installation stands that support the component while providing clearance underneath for the bearing and tools
Using tools matched to the bearing size can make the job easier while reducing the risk of scratching, cracking, distorting or otherwise damaging an expensive wheelchair wheel, fork or caster.
Can You Replace Wheelchair Bearings Yourself?
For someone comfortable carrying out basic mechanical work, bearing replacement can be a manageable piece of wheelchair maintenance when you have the correct replacement bearing and tools.
However, wheelchair designs vary, and some bearing assemblies are more complicated than others. Certain forks may use retaining rings, spacers or other hardware that needs to be removed and reinstalled correctly.
If you're uncertain about the bearing arrangement, cannot remove a bearing without excessive force, or aren't confident carrying out the work, having the wheelchair serviced by a suitably experienced technician is the better option.
Most importantly, don't force a bearing that doesn't appear to fit correctly.
Choosing the Correct Wheelchair Bearing
Before purchasing replacement bearings or bearing tools, identify exactly what is fitted to your wheelchair.
You can do this by:
- Checking the code printed or engraved on the existing bearing.
- Checking the wheelchair, wheel or fork manufacturer's specifications.
- Measuring the bearing's inside diameter, outside diameter and width.
- Confirming the axle or stem diameter where relevant.
Remember that the wheelchair model alone may not always tell you everything. Rear wheels, casters and forks can be changed or upgraded during the life of a wheelchair, so two chairs of the same model won't necessarily still have identical components.
If you're unsure, contact us with your wheelchair make and model, the component you're replacing the bearing in, and ideally a photo of the existing bearing or bearing code, and we can help identify the correct option.
Shop Wheelchair Bearings & Bearing Removal Tools
Keeping your wheelchair bearings in good condition can help maintain smooth rolling performance and prevent unnecessary wear on expensive wheelchair components.
Whether you're replacing a worn caster bearing, servicing a set of rear wheels or putting together the tools to maintain your own wheelchair, we stock a growing range of wheelchair bearings, bearing removal tools, installation tools and servicing equipment.