598 chapter 64
FEATURE
Rear bicycle wheel axle
and bearings
hub
metal plate
wheelchair
frame
Used machinery bearings
thin metal pipe
5/8” bolt
holes for
spokes
narrower tube
to hold
bearings apart
bearing
Wood bearing
washer
bolt (welded to fork)
oil-soaked
wood tube
metal fork
wood wheel
(oil-soaked hole)
bolt spot welded to fork
SUPPORT OF AXLES
Axle supported on one side
only
nut
axle passes
through
metal tube
welded to
frame
This is the standard
mount for factory-
built chairs.
Axle supported on both sides
This can be done in
several ways:
metal strips
on wood frame
metal tube on
tube frame
DESIGN DETAILS
• First take free-wheel
mechanism apart and
remove ratchets.
• Then attach
hub to a
metal plate
as shown
and spot
weld it.
• Other methods for
one-end axle support
are in the Healthlink
Manual (see p. 604).
• Find used high-speed
bearings of the size
shown (or near the
size). Volkswagen
alternator bearings
and certain power tool
bearings work well.
• Use 5/8 inch steel bolts
for axle. For details,
see p. 604, 622, and
623.
ADVANTAGES
• Allows axles to be
attached by one
end only.
• no need to adjust,
grease, or clean
• usually free or very
cheap
• In wheelchairs they will
last a very long time.
• If done well, results
are better than with
commercial hubs and
bearings.
• Use a hard wood
that will not split.
• Soak wood in old
motor oil.
• For more ideas and
details on wood
bearings, see
Healthlink Worldwide
Manual p. 604.
• Strong steel axles are
needed for support
at one side only. Axle
should be at least 5/8
inch thick for a large
person.
• For a very small child
bicycle axles can be
supported by one side
only. One way is to
weld bicycle axles to a
thin metal pipe.
• cheap and fairly easy
to make
• Not as wide or heavy
as the chair with
2-side support.
• easier for user to get
a full-length push
with hands and arms
• narrow size important
for doorways and
transporting
Pass pipe through
a wood frame,
• Place outer bar of axle
support so that it allows
as much room for hand
pushing by the rider as
possible.
single
caster
or weld to
metal frame.
• 2-sided support
allows use of
standard bicycle
wheels and axles.
• easy to build and
replace
re-bar
loop on
re-bar
frame
DISADVANTAGES
• Needs fairly skilled
work and welding.
• heavy
• very careful, exact
work needed for good
results
• tends to wear
out, wobble, or
crack quickly
unless very
well made; not
as smooth or easy
to ride as with ball
bearings
• For adults and large
children, standard
bicycle axles are too
weak for one-side
support.
• Even for smaller
children, bicycle
axles are weak, and
rough use can bend
them. Put a sign on
chair:
FOR SMALL
CHILDREN ONLY
• chair wider, more
difficult to get through
narrow doors and
spaces; more difficult to
transport
• Wheel supports get in
the way of hands when
user moves
by pushing
wheels.
• heavy
wood on wood frame
Disabled village Children