Pneumatic versus flat-free power wheelchair drive tires was a simple debate in years past. If you
wished a softer ride, pneumatic (air-filled), tires were the best choice, but at great risk of flats.
However, if you wished to eliminate the risk of flat tires, your best choice was a flat-free (foam-filled),
drive tire, but with a rougher ride quality.|
Fortunately, modern power wheelchair technology has
changed dramatically in recent years, making the choice between pneumatic and flat-free drive tires less
of a give-and-take, and more of an easy decision.
Drive Tire Construction
pneumatic drive tires are conventional by nature – featuring a soft rubber tire and an inner-tube, commonly
inflated to 35 PSI on most rehab power wheelchairs – and it's imperative to maintain the tire pressure
by properly inflating it approximately every two weeks. Of course, pneumatic drive tires are at risk
of puncture-related flats – actually quite easily because power wheelchair tires are relatively thin
– and to repair a flat tire, the power wheelchair must be elevated off of the ground, the drive wheel
removed, the rim unbolted in halves, the tube replaced or patched, then reassembled (needless to say,
not an achievable task for those with severe disabilities).
Flat-free drive tires are an outer
“pneumatic,” soft rubber tire, as well, but instead of an air-filled inner-tube, the void is filled with
a modern, specific-density foam, one that matches the tire's maximum PSI, where the ride quality equals
a fully-inflated tire. (More recently, an even newer flat-free tire construction has entered the global
market, where a layer of gel is placed atop the foam for a softer ride; however, thus far, the technology
proves problematic in that the tires equate to a “half-inflated” tire, dramatically increasing rolling
resistance and tire wear). Predictably, the absolute benefit to flat-free drive wheel tires is that they'll
never leave you stranded, and are maintenance free – that is, they typically don't need to be touched
until the tread wears out. (If you let foam-filled tires sit on an unused wheelchair for months in one
spot, they can develop a “flat spot” where the power wheelchair compressed the foam insert, but this
isn't an issue for regular users.) Lastly, foam-filled tires shouldn't be confused with polyurethane
“solid” tires, which aren't used on higher-end power wheelchair drive wheels due to limitations in durability
In all, if you look at a pneumatic and a foam-filled power wheelchair drive tires
side-by-side, you can't tell the difference – it's what's on the inside that sets them apart.
A foremost difference between pneumatic and flat-free drive tires that users have long noted
is that pneumatic tires offer a softer ride than flat-free tires. And, it's true – but only when pneumatic
tires are under inflated. Again, on an industry-standard 14”x3” drive tire, for example, the modern foam
density equates to the tire's maximum PSI rating, so when you compare, say, a 35 PSI foam-filled tire
to a properly inflated 35 PSI pneumatic tire, the ride quality and performance characteristics are truly
Now, a seeming advantage to pneumatic tires remains that the air pressure can be decreased
for a softer ride – but not without consequences. Reducing the air pressure in a tire increases rolling
resistance, which decreases battery range and dramatically increases tire wear. For these reasons, maintaining
maximum tire PSI is recommended – and if you need a softer ride, strive to address it at the power wheelchair's
suspension, not the tires.
Additionally, some users believe that decreasing the tire pressure
will increase traction, but there's simply not enough surface or volume on a typical 14”x3” power wheelchair
tire to dramatically alter the power wheelchair's performance by decreasing the air pressure. In fact,
lowering the tires' air pressure on 6-wheel power wheelchairs can actually decrease traction, as it redistributes
weight away from the center drive wheels, placing it on the front and rear casters, reducing drive wheel
traction. Therefore, when you hear people recommending lowering the air pressure on typical power wheelchair
tires to improve traction, they're truly misapplying techniques used on vastly different vehicles, and
don't understand the mechanical aspects of modern power wheelchairs, especially those in the 6-wheel
suspension arm class.
Unquestionably, pneumatic drive wheel tires are more efficient
than foam-filled, flat-free drive wheel tires. The fact is, foam-filled drive wheel tires are heavier
than pneumatic drive wheel tires, and a heavier wheel requires more energy to accelerate. Therefore,
each time a power wheelchair accelerates, it uses more energy doing so with a foam-filled drive wheel
tire than with a pneumatic tire. If you wish the absolutely most efficient drive wheel tire, then, pneumatic
is the best choice.
Still, drive wheel tire efficiency isn't only about the type of tire, but
it's also about how it's maintained. Again, pneumatic tires require routine inflation, and if not properly
maintained, a pneumatic tire that's low on air will dramatically decrease a power wheelchair's efficiency.
In this way, foam-filled tires can prove more efficient in the long term for those who don't routinely
air up their tires, as foam-filled tires consistently perform at a full PSI.
A Special Consideration
for 6-wheel Power Wheelchairs
Flat drive wheel tires on 6-wheel power wheelchairs can be especially
debilitating, rendering a power wheelchair all but inoperable. A flat tire on a rear- or front-wheel
drive power wheelchair will cause it to lean, but still drive at a reduced pace. However, when the drive
wheel goes flat on a 6-wheel power wheelchair, it redistributes the weight to the front and rear casters,
effectively high-centering the drive wheel, eliminating most traction. As a result, driving on flat ground
is very difficult, and ascending transitions like ramps is often impossible.
Can You Truly Afford
Ultimately the choice for many in deciding between pneumatic and foam-filled drive wheel
tires isn't about technology, but about abilities and lifestyle: Can you, personally, afford to get a
flat tire on your power wheelchair without it drastically affecting your life?
There are some
individuals who remain semi-ambulatory, with full upper body use – and are tinkerers by nature – who
are able and glad to roll their power wheelchairs into their garages and change a tire. For them, a flat
tire isn't debilitating, just a temporary task.
However, for others with severe disabilities,
where if their power wheelchair gets a flat tire, they have to rely on a provider, there can be great
consequences. For them, a flat tire can mean being without mobility for several days – a life-altering
In these ways, it's important to understand one's abilities and the potential consequences
of a flat tire, deciding whether pneumatics drive wheel tires are worth the risk, or if foam-filled,
flat-free tires are the securest solution?
Making the Call
While there are die-hard holdouts
who still swear by pneumatic drive wheel tires, it's increasingly difficult to dispute the overall merits
of foam-filled, flat-free drive wheel tires on modern power wheelchair technology. Under ideal circumstances
and maintenance, surely pneumatic drive wheel tires offer great efficiency and performance; however,
many users don't live in ideal circumstances, and can't risk flats. Furthermore, with specific-density
foam-filled tires, and most power wheelchairs now featuring suspension, the days of rough riding flat-free
tires are over. With all said, it's hard not to make the call that for users wishing utmost long-term
performance and reliability, foam-filled, flat-free tires become the easy choice on modern power wheelchairs.
Published 1/2010, Copyright 2010, WheelchairJunkie.com