Caster Wheels Flapping; Replacing The Caster Wheel Forks Replacing The Caster Wheel Forks - PRO ACTIV LITTY 4you Operating Instructions Service Booklet

18.2 Caster wheels flapping

Caster wheels flapping
Uncontrolled swivelling backwards and fo Uncontrolled swivelling backwards and for-
wards of the caster wheels around their axes r wheels around their axes
on the caster fork (while moving) is called "flu on the caster fork (while moving) is called "flut-
tering".
If the caster wheels start fluttering, then If the caster wheels start fluttering, then
immediately reduce the speed you are trave immediately reduce the speed you are travel-
ling at to avoid the caster wheels jamming ling at to avoid the caster wheels jamming
sideways so as to avoid the risk of fal sideways so as to avoid the risk of falling over.
The speed limit at which a caster wheel can The speed limit at which a caster wheel can
start fluttering, reduces with:

increasing size of the caster wheels increasing size of the caster wheels

increasing weight of caster wheels increasing weight of caster wheels

falling load on the caster wheels falling load on the caster wheels

decreasing caster length of caster wheels decreasing caster length of caster wheels
The following options are available to counte s are available to counter-
act caster fluttering:

Fluttering can be reduced by reducing the Fluttering can be reduced by reducing the
caster wheel diameter. This means instal caster wheel diameter. This means install-
ing a small caster wheel in a different ing a small caster wheel in a different
wheel position in the caster wheel fork wheel position in the caster wheel fork
(seat height thus remains the same) would (seat height thus remains the same) would
be one way of reducing fluttering. Ho one way of reducing fluttering. How-
ever, please note that using a smaller ever, please note that using a smaller
caster wheel makes it more difficult to caster wheel makes it more difficult to
overcome obstacles and makes tilting ne overcome obstacles and makes tilting nec-
essary more often. The smaller the caster essary more often. The smaller the caster
wheel is, the more driving skill is required. wheel is, the more driving skill is required.

Another way to reduce fluttering would for o reduce fluttering would for
example be to use a light caster wheel with example be to use a light caster wheel with
the same diameter or, as described above, the same diameter or, as described above,
with a smaller diameter.

It would also be possible to increase the It would also be possible to increase the
caster length. The caster length is the di caster length. The caster length is the dis-
tance between the rotary axle tance between the rotary axle of the caster
wheel fork projected onto the floor and the wheel fork projected onto the floor and the
wheel contact point. The wheel contact wheel contact point. The wheel contact
point of the caster wheel trails behind the point of the caster wheel trails behind the
rotary axle as it were. The caster length rotary axle as it were. The caster length
has a stabilizing effect on moving in a has a stabilizing effect on moving in a
straight line. Increasing the cas straight line. Increasing the caster length
can be attained by mounting the caster can be attained by mounting the caster
wheel in a different wheel position on the wheel in a different wheel position on the
caster wheel fork (the caster wheel fork r caster wheel fork (the caster wheel fork ro-
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Operating instructions LITTY 4you Operating instructions LITTY 4you
tary axle is then no longer completely at tary axle is then no longer completely at
right angles to the ground). right angles to the ground).
Rotary axle for
caster wheel
Wheel extension Wheel extension
point point
Caster length
Figure 23: Caster length
18.3 Replacing the caster wheel forks Replacing the caster wheel forks
A distinction needs to be made between the A distinction needs to be made between the
caster wheel forks with a bolt caster wheel forks with a bolt-on axle and
those with a quick-release axle. release axle.
18.3.1 Caster wheel fork with bolt Caster wheel fork with bolt-on axle
The caster wheel fork with a bolt caster wheel fork with a bolt-on axle is
removed using a wrench which is included in using a wrench which is included in
the scope of delivery. This wrench is inserted the scope of delivery. This wrench is inserted
into the two holes on the protective cap on the into the two holes on the protective cap on the
caster wheel bearing block and turned anti- caster wheel bearing block and turne
clockwise. The caster wheel fork needs to be clockwise. The caster wheel fork needs to be
held still. Once the cap has been completely held still. Once the cap has been completely
removed, the caster wheel fork can be pulled removed, the caster wheel fork can be pulled
out.