Usage instructions SPEEDY 4all & 4you & 4teen
38
When
mounting the caster wheel
, position
the caster wheel with its spacers in the caster
wheel fork, hold it in position and insert the M6
axle fixing screw with its washer from the out-
side of the product to the inside through the
axle of the caster wheel. Now attach the wash-
er and the M6 nut (AF 10 mm) from the other
side. The tightening torque of the axle fixing
screws (AF 4 mm) is 7 Nm.
22.2 Caster wheels flapping
Uncontrolled swivelling backwards and for-
wards of the caster wheels around their axes
on the caster fork (while moving) is known as
"fluttering".
If the caster wheels start to flutter, imme-
diately reduce your speed to prevent the caster
wheels from jamming sideways and therefore
reduce your risk of falling.
The
speed limit
where caster wheel fluttering
starts,
is reduced by
:
increasing size of the caster wheels
increase weight of the caster wheels
falling load on the caster wheels
decreasing caster length of caster wheels
The following options are available to
coun-
teract caster wheel fluttering in general
:
Fluttering can be reduced by
reducing the
caster wheel diameter
. This means in-
stalling a small caster wheel in a different
wheel position in the caster fork (seat
height thus remains the same) would be
one way of reducing fluttering. However,
please note that using a smaller caster
wheel makes it more difficult to overcome
obstacles and makes tipping necessary
more often. The smaller the caster wheel
is, the more driving skill is required.
Another option for reducing fluttering is to
use a
lighter caster wheel with the same
diameter
or, as described above,
with a
smaller diameter
.
Figure 101: Caster length
It is also possible to
increase the caster
length
. The caster length is the distance
between the rotary axle of the caster fork
projected onto the floor and the wheel con-
tact point. The wheel contact point of the
caster wheel trails behind the rotary axle
as it were. The caster length has a stabiliz-
ing effect on moving in a straight line. In-
creasing the caster length can be attained
by mounting the caster wheel in a different
wheel position on the caster fork (the in do-
ing so, the front seat height or the angel of
the seat changes, see Chapter 17.2). An-
other possibility is to bend the caster wheel
axle (see Chapter 22.4) forwards in the di-
rection of travel in the lower area. The an-
gle of the caster wheel axle can be adjust-
ed up to approximately 4 mm over the
length of the caster wheel bearing block
out of the vertical. This increases the cast-
er length and the tendency to vibrate re-
duces.
Caster wheel for rotary axle
Caster length
Wheel contact
point
