Off Road chairs, why do I need a Fieldmaster 224?
There are a few options available for wheelchair wheel arrangement;
1. Front Wheel Drive – This arrangement is able to descend a steep ramp but has the tendency to tip forward, also when it climbs a steep ramp it can loose grip and slip.
2. Rear Wheel Drive – This arrangement has the opposite problems as it will slide down a ramp, but climb well with the tendency to tip backward.
(Both these systems require twice their length to turn through 360 degrees)
3. Mid Wheel Drive – This arrangement means the chair can turn in just its own length so is more manoeuvrable. As the weight of the user is over the drive wheels it means it grips better up and down ramps, etc. However, two sets of castors are needed which require complicated springing to allow for going over bumps, etc.
These three options are fine for everyday use in the home and on pavements but unfortunately when attempting to go off-road these problems become magnified, the bumps are bigger and the hills are steeper, on top of that the ground can be loose, uneven, muddy, sandy or wet grass. The castors on the front and rear wheel drive have problems immediately, the front wheel drive will fair better as the drive wheels are at the front, but the castors will tend to sink into soft ground and try to steer the chair on uneven ground. Larger castors could be fitted to help this problem, but for everyday use they absorb more power and are difficult to turn on good surfaces.
So, mid wheel drive appears to be the answer to these problems, however, it has a major problem that can make it treacherous on steep inclines. All everyday chairs are made to go through a standard doorway which limits them to 26 inches (66cm) wide; this restricts their ability to cross slopes. When tackling a steep slope, up or down, you must always approach it square on as the chair will tip sideways if you attempt to turn across it. A mid wheel drive chair trying to climb a ramp that is too steep can loose its grip on one wheel first while the other is still gripping, the position of the weight will then cause the chair to spin around, if the wheel is still gripping it can turn the chair across the slope, causing the chair to tip sideways.
A four wheel drive chair with the user positioned mid way between the axles overcomes all these problems; you have four wheels driving in the correct direction and provides twice the grip of two wheel drive chairs. If traction is lost on one of the wheels, you still have three more continuing to travel so you carry on. Also, with no castors you never have direction problems on uneven surfaces and traction is much greater through mud or sand. However, some of the 4x4’s available are too wide to go through a standard doorway and they have a turning circle of several feet, this makes it unsuitable for use as an everyday chair.
That is except for the Fieldmaster 224. The 224 is 26 inches wide and easily converts to 2 wheel drive for everyday use. So it can be used indoors in two wheel drive and then on pavements, beaches, woodland and most other places in four wheel drive.
If you would like more information on our Fieldmaster chairs please do not hesitate to contact Clare on 01902 798633