Buying Tips for Bearings

Wheelchair and Scooter Bearings

Bearings are used when an object needs to rotate. On wheelchair and scooters, bearings are often found in the caster wheels, caster forks, rear wheels, suspension arms, swivel wheels, motors, and gearboxes. Bearings wear over time resulting in poor performance. There are some visible and auditory indicators that can help identify if a bearing is worn.

• Tire does not freely spin or requires added effort to rotate or push
• Surface rust
• Noises such as squeaks or grinding
• Complete bearing failure

Most wheelchair bearings are replaceable. Knowing the size of the bearing, reference number, and type of bearing can help you identify a replacement. See the image below showing how to characterize a bearing:

Many bearings found on wheelchairs and scooters have a reference number stamped on the side of the bearing which refers to the type and size of the bearing. In most cases, that is all you need to purchase the correct bearing. Suffixes indicate the type of seal or shield the bearing has such as rubber seals (RS, 2RS) or metal shields (Z, ZZ). If the bearing reference appears worn off, you may be able to see it stamped on the other side. You should also note whether the bearing has a flange or snap ring attached to it.

Some points to consider before purchasing (on manual wheelchairs):

• Caster wheels: Spin the casters to see if they spin freely - Inspect them closely for hair and other debris that may be caught or wrapped around the axle preventing them from moving freely.
• Caster forks: A bent caster fork can cause the chair to not roll easily or straight. You can also give the chair a shove on even ground - it should roll straight. If not, you may need caster forks instead of bearings. If the caster fork is wobbly, check that it is properly tightened as a loose caster fork can appear to be worn out bearings. Also make sure the dust cap is securely in place (on top of the stem) - this prevents debris and liquids from falling into the stem bearing.
• Rear wheels: The wheel itself should roll freely and not wobble. If the wheel is wobbly, check that the axle is secure and not wobbly. Many times a rear wheel with play is down to the axle not being tightened all the way. If you are using quick release axles and the wheel is a bit wobbly, it may just need to be adjusted (most quick release axles have an adjustment under the button to account for excess slack)

Installation

Remove the old bearings by pushing a long blunt object into the center of the bearing on one side to push out the bearing on the other side. You can use a screwdriver for this step, however it is recommended to push on the inner race of the bearing (the center part). Turn the caster or wheel over to do the same for the other. For manual or power wheelchair caster fork barrels, you'll have to remove the caster fork first. You can lay the wheelchair on its side (for manual wheelchairs) or prop up the wheelchair (for power wheelchairs). On wheels, there may be a spacer in between the bearings - save for later re-installation. For caster fork barrels, there can be multiple spacers and washers in a certain order which you must note to re-install. Most bearings seat into the space with little effort but some require a gentle pounding to get them in. You only want as much force as necessary to push the bearing in. Two much force can damage the wheel or housing. A rubber mallet works well for this (for casters and wheels, use a cloth or block wood with a cloth on both sides to prevent damage to the caster or wheel). Do one side, re-insert the spacer if you had one before, turn over and repeat. When reinstalling the axle and tightening, take care not to over tighten as this can put undue strain on the bearings.