6
tion with the back on the backrest) tips
backward on a surface with a 10° inclina-
tion (uphill in the forward direction) without
using external force (e.g. by pushing the
hand rims, shifting weight to the back, etc.),
the static stability is less than 10°.
Critical obstacles
If the castors of the wheelchair are stand-
ing on an obstacle with the critical obstacle
height and the drive wheels are positioned
exactly in front of this obstacle, the wheel-
chair will tip over backward when an attempt
is made at driving the wheelchair onto the
obstacle if the user does not actively shift
his body forward.
4.2 Wheel camber
The negative wheel camber will be carried
out according to your order. However, it can
be altered at all times by mounting the cor-
responding camber adapter.
For wheel holders that are mounted on the
inside, only a 1° camber can be mounted
(we recommend using only wheel holders
mounted on the inside for body weights
of up to approx. 80 kg). For wheel holders
mounted on the outside, a camber of 1°, 4°,
6° and 12° is possible.
A wheel camber not only increases the
stand stability at the side of your wheelchair
but also widens the track (overall width) of
the wheelchair.
Contact your medical supplies dealer or
PRO ACTIV if you wish to alter the wheel
camber or if you wish to mount the wheel
holder on the outside instead of the inside
and vice-versa.
4. TIPPING AND TURNING STABILITY
Easy tipping and turning stability of the
wheelchair can be achieved when the axle
mount of the drive wheels is located near
to the centre of gravity of the wheelchair
user. Moving the drive wheels further back
reduces the risk of the wheelchair tipping
but also makes it more difficult to turn and
steer. Settings, however, should be made
according to the requirements/ability of
each individual to ensure safe driving.
4.1 Positioning drive wheels
Remove the drive wheels from the quick-
release axles.
If possible, loosen the inner fixing nut (Fig.
4 b) with a SW 30 screwdriver (to avoid
scratches on the outer side of the wheel
holder, push the socket along the slot and
tighten the nut again with a torque of 75
Nm.
Ensure that the sockets on the left and
right are at the same position on the wheel
holder. A scale can be found on the wheel
holders to check correct positioning.
IMPORTANT
After shifting the axle mount for the drive
wheels, check the wheel track and readjust
if necessary. Also readjust the castor axle
and the brakes accordingly (see 6.1-6.2 and
6.4).
IMPORTANT
Extreme settings, for example, drive wheels
that are mounted much further forward are
only permitted for practised drivers who can
shift their weight forward when driving. We
urgently recommend using anti-tip supports
for settings where the static stability angle
in the backward direction is less than 10° or
a critical obstacle height is less than 5 cm.
To minimise the risk of tipping backward, we
recommend using anti-tip supports even for
settings where the wheelchair cannot tip.
Static stability in the backward direction
If the wheelchair with user (upright posi-
