You are here: Home > Support Center
Custom Upholstery Wheelchair Terms Bearing Sizing Chart
Color Chart

Support Center


What if I cannot describe nor find what I need?
Many parts are known by several different names depending on the wheelchair manufacturer.
Please email us a picture and some measurements of the part to be replaced, and our Customer Service will look into it for you.
Caster Guide - How to measure wheelchair casters
An easy way to find out the caster axle size, use an open end or box wrench:
If a 1/2 inch wrench fits the axle bolt head, it is a 5/16" axle.
If a 5/8 inch wrench fits the axle bolt head, it is a 7/16" axle.

(Caster Axle Size = Bearing ID)
When measuring bearings, do not measure the flange diameter!


Size of the caster with a solid tire: Measure from the floor to the very top of the caster, than round up to the next whole number to allow for wear.
Size of the caster with a pneumatic tire: The size is on the side of the old tire.

Width of the caster: Measure across the tire.

Hub Width: To measure the caster hub width, the best method is to remove the caster from the wheelchair and measure as shown below:
how to measure a hub width

Bearing Guide - What else do I need to know about bearings?
Wheelchair bearings come in a variety of styles and sizes depending on what manufacturer made the wheelchair and what type of wheelchair it is. Bearings for a standard wheelchair will not always fit a lightweight wheelchair.

Wheelchair bearings come in three types:
Stem Bearings: The stem bearings are located where the front fork attaches to the wheelchair frame.
Caster Bearings: The caster bearings are located in the caster/ front wheels.
Wheel Bearings: The rear wheel bearings are located in the rear wheels.
drawing of bearing types

Understanding bearing sizes: If you do not know the brand or cannot find it, you will need to know the bearing size. Wheelchair bearings are sized by, axle diameter (or bearings inside diameter) X the bearings outside diameter. The standard Invacare caster uses a 7/16" diameter axle and the bearing outside diameter is 29/32", so the bearing will be listed as 7/16 ID X 29/32 OD.

QUICK TIP:
An easy way to find out the caster axle size, use an open end or box wrench:
If a 1/2 inch wrench fits the axle bolt head, it is a 5/16" axle.
If a 5/8 inch wrench fits the axle bolt head, it is a 7/16" axle.

When measuring bearings, do not measure the flange diameter!



Download our Bearing Sizing Chart: Bearing Template (Do not scale when printing / Print actual size.)

Wheelchair Guide - A guide to buying the right wheelchair
Picking a wheelchair that fits best to your needs is not really that difficult. The main thing to know is the size you need, the wheelchair style you want, and what type footrest and armrest works best for you.

1) SEAT SIZE
Probably the most important information to provide is the seat width, depth, and height.)

Seat Width: A good way to get an accurate measurement is to sit on a measuring tape and add 1-2 inches on each side for winter coats, heavy clothing, etc.

Seat Depth: While sitting upright in a chair, measure from the back of the seat to about 2 inches behind the knees. The seat should be long enough to provide proper leg support without rubbing against the back of the lower legs.

Seat Height: Using a seat cushion is highly recommended if spending a lot of time in the chair. Please consider the thickness of the cushion when determining the seat height.

Users Height Seat Height
5'4" and above standard: 19"-21"
5'4" and under hemi: 17"-18"
4'11" and under super hemi: 14"-16"



2) WHEELCHAIR STYLES
Standard Wheelchairs
User weight: < 300 lbs
Self propelling ability: User can self propel easily or has someone that pushes the chair
Wheelchair weight: Up to 45 lbs
* Less expensive than a lightweight wheelchair

Lightweight Wheelchairs
User weight: < 300 lbs
Self propelling ability: User can self propel less easily or has someone that pushes the chair
Wheelchair weight: Up to 34 lbs
* Most popular type wheelchair

Heavy Duty, Extra Wide, or Bariatric Wheelchairs
User weight: 300 - 1000 lbs.
Wheelchair weight: Some models are very heavy

Reclining Wheelchair
Wheelchair weight: Heavy and very difficult to transport.
* Only recommended for people that need to be in a prone position at times

Transport or Companion Wheelchair
Wheelchair weight: Lightweight and easy to transport.
Self propelling ability: User cannot self propel by hand. User either must have someone to push the chair or uses the feet to scoot along.
* For occasional use. Many models have a folding back and fit in a car trunk very easily.


3) FRONT RIGGINGS
One potential problem with front rigging is that the more the footrest sticks out, the harder it is to maneuver the wheelchair. Listed below are the two different types of front riggings available.

Footrests: This is the best choice, if there is no need to elevate legs due to swelling or other issues. To get easier into and out of the chair chose swing-away footrests. However, footrests do not have calf pads to help support the leg.

Elevating Legrests: This is the best choice, if there is the need to elevate legs due to swelling or other issues. Legrests do have calf pads to help support the leg.

Articulating Legrests: Like elevating legrests, the only difference is that the footplate extends out a few inches while elevated. Often not necessary, but it might be helpful to some people.


4) ARMRESTS
Desk Length Arms: Helpful for getting closer to tables, etc. Only available in detachable style, which also makes transfers easier.

Full Length Arms: Helpful if the extra length is needed to push yourself up from the chair, or if extra arm support is needed. Full length arms are available in a fixed or detachable style.
Note: Fixed full length arms take about 2 inches off the available seat width. If you have fixed arms and an 18 inch wide seat, you will have 16 inches between the arms, unless it is offset. This can be a problem for some people.

Height Adjustable Arms: Helpful if the user is taller or shorter than normal. Height adjustable arms are available as full or desk length.

Parts Guide - Replacing/Interchanging Wheelchair Parts
Most standard wheelchairs are based on Invacare or E&J (Everest & Jennings) designs, so many wheelchair parts will interchange among brands. This is not necessarily as true for lightweight wheelchairs or transport/companion chairs and there is of course always a chance of finding an odd model. Please double check before ordering.

It is always best to take your own measurements and compare it to the measurements provided on our product pages. This guide can help you narrow down the search.

Wheelchair Brand Upholstery 8" Casters Bearings Wheels
Everest & Jennings (E&J) E&J E&J E&J E&J
Invacare Invacare Invacare Invacare Invacare
Guardian E&J E&J E&J E&J
Hoyer E&J E&J E&J E&J
Lumex E&J E&J E&J E&J
Smith & Davis (S&D) E&J E&J E&J E&J
Tuffcare E&J E&J E&J E&J
Theradyne
C, D, E, G Series
E&J Depends on
axle size
Depends on
axle size
Theradyne
Theradyne
A Series
Invacare Depends on
axle size
Depends on
axle size
Theradyne
Colson Invacare Invacare Invacare Invacare
Rolls Invacare Invacare Invacare Invacare
Quickie Quickie 5/16 Brg Quickie Quickie
Breezy Breezy 5/16 Brg Quickie Quickie
Evermed Evermed 7/16 Brg Invacare Invacare
Gendron Gendron 7/16 Brg Gendron Gendron



Footrest Guide - A guide to finding the right footrest
Note: Some footrest attachments are very similar with only small differences. Please double check before ordering to avoid restocking fees.

There are 4 very common (and brand interchangeable) footrest styles:
Invacare Standard Invacare Hemi
Hanger Spacing (on frame): 3-1/4" Hanger Spacing (on frame): 1-1/2"
Hanger Pins (holes in footrest): 1/4" in diameter Hanger Pins (holes in footrest): 1/4" in diameter
Locking Mechanism: On top Locking Mechanism: On top
standard invacare footrest hanger hemi invacare footrest hanger
Fits many different brands including Invacare, Evermed, Medline, some Rolls, and many others.
Notice that the top pin platform extends to the inside of the wheelchair frame?
This is where the footrest latches.


E&J Standard (NO LONGER AVAILABLE) E&J Hemi
Hanger Spacing (on frame): 3-1/4" Hanger Spacing (on frame): 2-1/4"
Hanger Pins (holes in footrest): 5/16" in diameter Hanger Pins (holes in footrest): 5/16" in diameter
Locking Mechanism: On bottom Locking Mechanism: On bottom
standard everest and jennings footrest hanger hemi everest and jennings footrest hanger
Fits many different brands including E&J, Smith & Davis (S&D), Theradyne, and a few others.
Notice that the bottom pin platform extends to the inside of the wheelchair frame?
This is where the footrest latches.



Pinlock Style: This is an old style of footrest attachment used by E&J, Smith & Davis (S&D), Theradyne, and a few others. Unfortunately this style has been discontinued and is no longer available to us.

Quickie Style: Currently, we do not carry this style. (Picture shown below as reference.)
quickie footrest hanger

Tire Guide - What size is my tire?
The size of most pneumatic wheelchair tires can be found on the outside wall/side of the old tire.
The size can be in one of several forms such as 24 x 1-3/8", 37-540, 300-8, or 410/350-4. Tires can also be called several different things for the same size of tire. A 10 x 3" tire is also known as 260 x 85, or 300-4.

If in doubt of the size, write down all the numbers you can find on the side of the old tire and contact us!

Flat free wheelchair tires are also known as foam filled tires. They are the standard tires filled with poly-foam and require a two piece wheel. Flat free inner tubes are made from urethane foam and can be difficult to install without the proper tools.

Please look at our YouTube Videos on how to install tires and/or air free inserts!

Helpful Information: Product Videos
Please check out all our product videos on one page.
Frog Legs? Shock Absorbers Installation Instructions
Tools required to install caster fork:
Small flat head (regular) screwdriver
3/4 inch (19mm) socket and ratchet

Tools required to install caster wheel:
2 allen wrenches: 5/32 inch (4mm)



Directions for Installing Frog Legs Shock Absorbers

Step 1. Use a small screwdriver to remove the plastic cover or dust cap from the top of the caster barrel housing. Find the seam between the cap and caster barrel, and pry up with the screw driver. (See diagram above for caster barrel details.)

Step 2. Use a 3/4 inch (19mm) socket and ratchet to remove the nylock nut located below the dust cap removed in Step 1. The rigid fork assembly will have to be held in place to remove the nut. Usually this can be held by hand, but bracing the assembly against a hard surface will also work. One the nut is removed, the rigid fork assembly can be removed from the caster barrel housing.

Note: A bag of hardware containing new nylock nuts, washers, etc. are supplied with your Frog Legs forks.

Step 3. If your existing caster wheel is 6 inches in diameter or less and you would like to use this wheel for your new suspension system, then this wheel has to be removed from the old rigid fork. Depending on the type of rigid system you currently have, you may have to find some additional tools to remove the caster wheel. Once the wheel is removed, it can be installed on your new Frog Legs Shock Absorbers.

Supplied with your new set are (2) axle pins, (2) button-head screws and (4) wheel spacers you will need to attach your new caster wheels to your new forks. First choose one of the three axle location holes in your new forks, and then put the axle bolt partially through the hole. Add one of the provided spacers, or use your rigid system spacer if you have them. Next, insert the wheel, push the axle through the wheel and then add another spacer. Push the axle bolt through the other side of the fork. Install the button-head screw that came with the axle pin and tighten the assembly.

Step 4. Install the suspension fork assembly on the chair by inserting the stem of the suspension assembly into caster barrel housing on your chair. See above diagram. Install the new nylock nut on the stem bolt with the ? inch (19mm) socket and ratchet. Tighten this nut until all vertical stem play is removed. Over tightening will result in a fork assembly that will not swivel freely. If this occurs, simply loosen the stem nylock nut until fork assembly rotates freely.

Step 5. Snap the dust cover back in place on top of the caster barrel housing. This completes the installation.



Thank you for your business and have a wonderful day!
Your Mobility Direct Team

Mobility Direct brand logo