"road test" a "repaired" power chair or scooter without "testing"
it with the drive wheels off the ground first.
CARE AND MAINTENANCE:
STUFF YOU SHOULD DO YOURSELF:
Visually and "feel" check your chair at least once a week and whenever
it doesn't feel right:
Make sure the rear wheels aren't too loose.
Check the front forks for too much play.
Look at the frame for rust and cracks.
Look for torn upholstery. Make sure the upholstery screws are
tight, but don't over tighten.
Check for loose spokes (if applicable) by "twanging" each one.
If you get (hear/feel) a "thunk", see a qualified technician.
Check the wheel locks (aka brakes). This should be "automatic"
as you use them.
Check the quick release axles (if so equipped) for fit and
function. Also check each time used.
All of the above require immediate professional attention if not
correct.
Keep the chair dry. If it gets wet, dry off with a towel asap.
Clean the chair. But don't ever use water (or steam) under pressure.
Check and maintain tire pressure (if applicable).
Prevent all electronics (on power chairs and scooters) from getting
wet.
Check all connections on power chairs and scooters every couple of
months.
Check water level if you have wet batteries every couple of months.
Bring the chair to a qualified technician for a checkup at least once
a year.
STUFF YOU =MAY= DO YOURSELF IF YOU FEEL QUALIFIED:
Tighten all bolts that are supposed to be tight. NOTE: this requires
knowledge of the chair. DO NOT attempt this unless you know what is
supposed to be tight and what is not! You must also know HOW TIGHT!
Lubricate with the correct lubricants the areas that allow the chair
to fold, folding footplates, brakes, etc. NOTE: this requires
knowledge of the chair. DO NOT attempt this unless you know what is
supposed to be lubricated and what kind to use. Example: most
bearings NEVER require any lubrication whatsoever. They are sealed
and spraying them with WD-40 will actually ruin them by washing out
the grease under the seals. WD-40 is more of a solvent than a
lubricant, but will work fine on wheel locks, guide tips, and that
type of areas. Conversely, no "oil" should be used on a drive chain as
it will hold sand and other abrasives (use white lithium grease
aerosol available in auto stores. Goes on wet, dries to a "soap").
Adjust belts on power chairs. NOTE: this requires knowledge of the
chair. DO NOT attempt this unless you know what the procedure and
tension should be. Anyone with an Invacare Arrow Belt Drive is better
off NEVER ADJUSTING the belts or tensioners, DON'T HAVE THE TECHNICIAN
adjust them either, accept under extreme conditions (like when someone
else mis-adjusted them).
WHERE DO I GET THE KNOWLEDGE TO DO THE ABOVE?
If the chair has a manual, read it. Then ask a qualified technician
to point out the relevant adjustments, tightness, and lubrication
points. While I may have made it sound complicated, most of the stuff
mentioned above can be checked out in ten minutes or less. Actual
adjustments if required will take longer.
STUFF THAT SHOULD BE LEFT TO A QUALIFIED TECHNICIAN:
Any and all repairs that you feel uncomfortable or unqualified to do.
All electrical problems, with the possible exception of battery
replacement if you know the safe procedure to change the batteries.
Never, ever, open the control module of a power chair. There are no
user serviceable components inside.
Frame replacements on most chairs.
"Truing" of wheels. Many times we can't either- we have to refer the
customer to a bicycle shop, and may times they can't true the wheel
either.
ADDING AIR:
Always use a "manual" air pump. Electric pumps, even the "automobile"
style, can add too much air too quickly blowing the tire off the rim.
Foot pumps are excellent, inexpensive, and can be used by "hand" as
well. K-mart sells them for under $10. The gauge on the pump will be
accurate enough for most users (true sport chair users will have their
own equipment).
CHANGING A TIRE, FIXING A FLAT
This is something that most 10 year old kids in the neighborhood think
they can do, so I will lay out the "proper" way (it's faster too).
I usually don't recommend patching tubes. Particularly front caster
ones. Replacement tubes are just too cheap these days to risk a
blowout due to a poor patch job. Here in Florida the tubes tend to
"dry rot" rather quickly- making patching impossible anyway. A dry
rotted tube feels rough and "gritty" when rubbed between the fingers.
Black from the tube will remain on one's fingers as well. A good
inner tube will feel smooth and leave no black. Dry rotted tires will
have cracks on the outer sidewalls. If bad enough, they will pinch
the tube and cause a flat.
Tools required: "manual" air pump, bicycle tire "spoons" (available
at K-mart really cheap), Soapy water.
Using tire spoons (never, ever use a screwdriver to remove/install a
tube you want to reuse), remove the (flat) tire. If the tube is still
holding air, remove the air before attempting to remove the tire.
Check the rim. If it's a steel spoked rim (as opposed to molded
plastic), make sure no spokes are poking up through the rim or rubber
spoke guard to puncture the tube. Make sure the rubber spoke guard is
in place and in good condition. Bike (and wheelchair) shops sell
replacement ones, and electrical tape works just as well.
Inflate the new inner tube so it just starts to have it's "shape".
Insert the tube into the tire (tire is NOT on the rim at this time).
A slightly inflated tube will not "pinch" as easily as a deflated one
when installed. Obviously too much air will make it difficult or
impossible to install the tire.
Lubricate the tire with the soapy water. Don't be stingy.
Insert the tire/tube over the rim (if the handrim is in the way, go
from the "rear") and insert the air valve into the hole. Screw the
dust cap onto the valve to keep it from falling out of the hole and
inside the tire.
Work the tire around the rim so that one side of the tire is on the
rim. No tools should be necessary for this. Start the other side
onto the rim, making sure the tube is not pinched.
Some rims will "allow" you to put the entire tube on without tools.
This is easier at this point, but will require more attention to
"centering" when air is added. Use the tire spoons to ease the last
section of tire over the rim if necessary.
Move the tire in relationship to the wheel so the valve is straight
through the hole- not on any angle that could cause the rim to bite
into the valve.
Keep the tire "centered" on the rim, add more air, stop at 20 lbs,
check that the tire is centered on both sides of the rim, all the way
around the tire. There is usually a guide line on the tire to act as
a visual reference. Add more air to the maximum rating on the tire,
stopping at 40 (if going above) for another check. Even if you want
less air (for a softer ride), go to the maximum rated on the tire to
"seat" the tire, then "bleed" air from it to the desired pressure.
SOLID TIRES, INSERTS, TUBE GUARDS, & INNER TUBES:
Solid rubber tires never need air, never go flat, but provide a very
hard ride with traction problems, particularly on wet and sandy
surfaces. For spinal cord injured users, the hard ride, even with an
"air" cushion (Roho type), may preclude solid tires on all 4 wheels.
Some users will select solid casters with pneumatic rears, and keep
the front end "light" (rear wheel placement more forward). However
the pneumatics do require maintenance and go flat. To reduce the
chance of flats, a tire that is Kevlar belted is available. Kevlar is
the same material used in bullet proof vests. Thicker INNER TUBES are
also available (called thorn resistant)- they add some weight but not
as much as an insert. Another device is called a tube guard. It is
a flat piece of plastic the length of the circumference of the tire
that is placed between the tube and the tire. Flats are still
possible with all these preventative measures, but the odds decrease.
Air pressure must still be maintained.
To eliminate flats and adding air altogether, pneumatic tires can be
replaced with solid ones, or with a variety of "inserts" that fit
inside the tire where the inner tube used to be. Different kinds of
inserts have different characteristics, some are "softer" (cushier
ride like with less air pressure), most people like the American
Airless style that seem to emulate a pneumatic tire with 55 lbs of air
in it. All inserts add some additional weight to the chair- plastic
or foam rubber weighs more than air.
For some sizes, the tire and insert come as a "set"- the insert must
be molded into the tire at the (insert) factory. For others, the
insert can be installed on an existing tire- assuming the condition
and size (specifications) of the tire are appropriate for the insert.
Once the insert is installed, the tire CANNOT BE REMOVED without
destroying the tire (it must be cut from the rim). Furthermore, many
times the rim is also damaged upon removal of the tire in such a way
that it can never be used with an inner tube again (will work fine
with inserts). So one must be sure that the insert is an appropriate
alternative to the inner tube before proceeding.
Some scooter manufacturers fill INNER TUBES with a rubber chemical
that became solid (instead of using inserts). Our experience is that
at least in the heat of Florida, the solid mass in that inner tube
becomes a tar (liquid) again, bursting the tube and leaving a tar
trail wherever the scooter goes (and the "flat free" tire goes flat as
well). I do not recommend "filled' INNER TUBES as a substitute for
inserts.
REPAIR "FAQ's" (manual and electric)
Q: Why do my front wheels wobble? I don't understand why that
happens. I tighten the nuts and that stops the wobble for a while
but I don't feel that that's the solution. I use a power chair.
A: Many wheelchairs have the problem of front wheel "flutter". The
problem is not limited to power chairs, but because of the nature
of fluttering, it may happen more at higher speeds. Tightening
the stem nuts on the fork binds the bearings not allowing for the
fluttering. Unfortunately, it makes the chair harder to steer at
low speeds, and wrecks the bearings.
21st Century Scientific had an "fix" for E&J's that replaced the
upper bearings with a nylon bushing that "grabbed" the stem
tighter. It worked well until it wore out (the hole got bigger),
then the problem got worse. I solve the problem 3 ways:
1. Have the user put more weight on the front rigging if possible.
2. Use a bigger (wider) front caster- or let some air out of the front
casters. This gives more "friction" on the road and doesn't allow
the fluttering to start. It is the only time that worn out solid
casters work better than new ones .
3. I remove the upper bearings on the fork stems, pack shredded
styrofoam (from drink cups) into the space as tight as possible, then
replace the upper bearings. As the "hole" wears bigger in time, I
remove the upper bearings again and add more styrofoam. It works
better then the 21st Century product, but is time consuming.
On some power chairs, the angle of the front casters can be adjusted
by using a fork with multiple holes in it. This will also deal with
the fluttering (if you can find a fork with the holes for your chair).
Q. What can I put into my inner tubes to eliminate or fix flats?
A: Nothing from a can or bottle. The "fix it/prevent it" stuff sold
at automotive stores and bike shops just doesn't seem to ever work
(or maybe I just see the ones that didn't work...). My experience
is that they don't, or at least not for long. All they do is make
a mess (on your floor- and mine when I do the repair). You can
use a heavier inner tube (sometimes called a thorn resistant inner
tube a plastic "guard" between the inner tube and the tire
(available at bike shops, some wheelchair dealers, and K-mart), or
a tire made of the same materials as bullet proof vests are:
Kevlar (I'm serious). See above regarding inserts for more
information and an alternative.
Q: Why can't I use a "plug" to repair my tire?
A: 'Wheelchair tires have INNER TUBES in them. I have never seen a
tubeless wheel on a wheelchair or scooter.
Q. I have a hospital style wheelchair and the plastic piece that keeps
the frame together keeps breaking every few weeks. What can I do?
A: You are describing a guide tip. Fixed arm hospital style
wheelchairs have 4 of them (one in each corner of the seat) and
removable arm hospital-style chairs have 2 (rear of seat only) that
ride up and down the side frames allowing the chair to fold. Most
"rigid" frame folding chairs do not have these (only exception I
can think of is Quickie Breezy). They are breaking because they
have been installed incorrectly, the wrong ones have been installed
for that particular chair, or some frame is very bent on the chair.
While the plastic tips do get brittle over years, replacement more
than once every 3 years means something else is wrong with the
chair. If you are "snapping' these into place without dissembling
the chair, that could be the problem as well. They must fit tight
(some Invacare chairs have them spring loaded), but cannot be
forced in place. It requires a knowledge of the chair to install.
See your repair technician. This "easy" job must be done
correctly.
BACK to Wheelchairs and Scooters menu
All the information provided herein is Copyright © 1993 1994 1995
1996 1997 1998 1999 2000, & 2001 Stuart L. Portner. All rights reserved. May be
printed and reproduced for individual use, but may not be distributed
without the permission of the author.
While wheelchairs appear to be simple (I wish I had a nickel for every
time I'm told how "easy" it appears to repair a chair), even a "basic"
job like replacing a seat (after all, "it's only some screws")
requires knowledge of the construction of the chair and concepts that
=must= be followed. Example: most seats and backs, while only held in
place by some screws, have metal strips hidden inside that =must= have
the screws go through holes in the strips. Miss the holes and the
seat gives way, possibly causing injury. The seat also has a "top",
"bottom", "front" and "back". And on some chairs (many Invacare
models and others), the rear seat screws also hold 2 hidden springs in
place against guide tips that allow the chair to fold. Miss the
springs and the chair may fall apart.
