One of the most important components of a powerchair is the wheel traction, which enables a chair to move over different types of terrain.
Not everyone plans on racing across canyon land, but even if you use your chair primarily indoors, you inevitably end up outside and need stability.
This is why it’s important to have quality traction. In this guide, we discuss exactly how to achieve this-even without investing in specialized tires.
What is Wheel Traction?
Before we get into the intricacies of the powerchair wheelbase, it’s essential to understand what traction is and why it’s important.
Traction is a type of friction that occurs between the rubber tire and the ground. Other factors, such as the weight of the wheelchair and the surface area covered by the tire, contribute to traction performance.
For example, a heavy power wheelchair with large, wide tires has more traction off-road than a lightweight model with skinny tires.
Without enough traction, a powerchair might have difficulties traveling off-road, resulting in sliding or sinking and getting stuck in place.
Understanding Different Drive Modes
Now that we know that traction helps powerchair tires stick to the ground and move easily, let’s take a closer look at the different types of wheels a powerchair might have.
With this type of setup, a powerchair has a larger driving wheel at the front of the chair. It allows the user to climb up curbs and tackle other inclines with ease.
That’s because the design distributes the user’s weight over the drive wheels, creating more stability and increased traction.
This is an ideal setup for off-roading and for use in environments that require maneuvering in tight spaces, such as an office or driving in a car.
With this powerchair wheelbase, the driving wheels are situated towards the center, while castors are positioned at the front and rear.
This is also a suitable choice for tight maneuvering and off-roading, as the castors create an excellent center of gravity by keeping constant contact with the ground.
The stability also increases traction when traveling up or down an incline, preventing the wheelchair from tipping.
As you can probably guess, the drive wheels are stationed at the back of the chair, while castors are placed at the front.
That means you’re going to have most of the weight distributed at the back of the powerchair, which enhances control when climbing or tracking.
This rear weight distribution also increases speed performance, smoothing out the ride while off-road.
For maximum off-road traction and agility, four-wheel drive is your best bet, with four tires that are each powered by its own motor.
With weight evenly distributed across all four wheels, you’re set to tackle some serious off-roading adventures!
The Importance of Wheel Size
Got the different wheelbases down? Now it’s time to roll into the role wheel size plays in increasing traction of the wheelchair.
The last thing you want is to feel your powerchair’s tires sink into the soft ground or start spinning. If you’re not careful, you can end up stuck in the middle of nowhere!
Sinking and spinning signify that your chair is quickly losing traction. Instead, you want torque matching traction, where you feel the tire adhering to the ground.
The best way to achieve this is with wide tires, as skinny tires lack the proper torque/traction ratio to keep your wheels from digging a rut.
The tricky part is finding tires that are just wide enough. If they are too wide, you won’t be able to maneuver your powerchair comfortably indoors.
Even 10” wide drive wheels wouldn’t be able to fit inside a bathroom. Therefore, a smarter and more cost-effective solution would be to increase the traction of the tires you already have on your chair.
How to Increase Wheelchair Off-Road Traction
At this point, you might be wondering how you could possibly increase the traction of your tires. You’ll be surprised to learn it’s easier than you may think.
All you have to do is decrease the air pressure– a trick that off-roaders have utilized for years.
When a tire is fully inflated, it bulges out towards the center of the tread. If you were to study the tread of a new tire with the max PSI rating, you would probably see that the center is worn, but the sides are still fresh from not touching the ground.
That means the entire tread is not being used, decreasing the amount of traction.
This is fine for indoor use since the environment is not taxing on the chair, but this just won’t suffice for off-roading.
To increase the traction, deflate the air pressure until the tread is flattened out, creating a full tire pattern that initiates complete contact on the ground.
Every model is different, so you’ll want to consult your owner’s manual and experiment a bit to find the best pressure.
For reference, the most common wheelchair tire size is 3.00- 8 tires, so lowering from 35PSI to 15PSI is probably acceptable for both indoor and outdoor use.
The Advantages of a Lower PSI
Safety is always of concern when meddling with a powerchair. When it comes to lowering the PSI of the tires, you don’t have to worry about damages. Overinflating is more dangerous, as the tire can explode!
In fact, a lower PSI offers some neat advantages. And, if you don’t like the feel, you can always inflate your tires back to the normal PSI rating.
Here are some of the benefits that come with reduced tire pressure.
- It increases the pulling power.
- The tires can adhere and climb over obstacles.
Final Thoughts on Powerchair Drive-Wheel Traction
If you plan on embarking on more off-roading adventures with your powerchair, it’s important to test out the wheel traction, which can be the deciding factor for whether you rocket over a slope or get stuck in a rut.
Generally, wider wheels equal better traction, but this isn’t ideal for indoor maneuverability. Therefore the easiest way to increase traction is to lower the PSI of your current tires.
Lowering the PSI allows the full footprint of the tread to connect with the ground, improving outdoor performance without sacrificing ease of use at home.
Resources & References:
Tire-Road Friction Estimation and Traction Control Strategy For Motorized Electric Vehicle, PubMed