We use this trick all the time in our shop at Disability Lab when we do not know what size of wheelchair tire is, especially when the tire has no markings. Use this trick the next time you need need wheelchair tires to make sure you are buying the right ones.
Biggest Issue with Tire Sizes
One the biggest issues with wheelchair tire sizes that the way we refer to them, for example a 24" tire, is not very accurate. In fact if you where to go into a bike shop and ask for a 24" tire you would get a 24" BMX tire that is much smaller then a 24" wheelchair tire. Because of this inaccuracy we have found that if you use the metric tire measurement to be precise. For example a 24" wheelchair tire is 540 millimeters on the inside. A any 540 millimeter tire will fit any 540 millimeter rim.
Video
Here is the break down of our measurement trick.
- Measure across that wheel from the outside of the rim to the outside of the rim on the opposite size to the nearest 1/4".
- Take that Measurement in inches and convert to to millimeters by multiplying the number my 25.4
- Subtract 10mm from the number to take into account of the rim depth
- Compare that final number to the chart below to determine your tire size
Here is a chart that converts popular wheelchair tire sizes from inches to millimeters:
| Tire Size in Inches | Tire Size in Millmeters |
|
22" |
501 mm |
| 24" | 540 mm |
| 25" | 559 mm |
| 26" | 590 mm |
Now you have an easy to way to determine the tire size of any wheelchair wheel even if it has a tire on it or not.
If you have any questions contact us, we would be happy to help.