Long-wheelbase wheelchair

[Rev. Green]

Does anyone know of a wheelchair manufacturer who makes a lightweight wheelchair with large rear wheels and a wheelbase of at least 40cm?
All the wheelchairs which we have tried which weigh less than 15kg have a short wheelbase and are unstable. We have only found steel wheelchairs with a long wheelbase: they are stable but too heavy.
All wheelchairs are stable on pavements and in hospital corridors, but this wheelchair user wants to explore country paths which have gravel patches. The lightweight chairs tip forward if they hit stones as small as 18mm diameter.

[alavahalf]

Some years ago I used to work for a Ministry of Health contractor. We used to make one off chairs for various special needs. Sorry but the business has been closed for some time now.
To make a wheelchair more stable what you would do is set the rear wheels further back. As in making a bracket with a wheel mount, and welding it in place behind the existing mounting position, attached to the down tube and the lower frame tube.
Just a point to consider... when the wheels are set back, the chair becomes more difficult to manouvere.
This type of chair was usually made for an amputee... having less weight forward
(no legs) meant the conventional chair was prone to tipping backwards.
If I had to get this done I should look for an engineering work shop, and describe what you want. It should'nt be to difficult.

[Rev. Green]

Many thanks Alavahalf. Great idea. The wheelchair always tips forwards, so I'll see if the local engineering firm can make brackets to mount the front wheels further forwards and out to the side (to miss the footrests).

[marcwebster]

Hmm… I’m not really sure. Don’t bigger rear wheels are more unstable? I’m thinking the way it is with cars. Or you just need wider wheels and not bigger ones. It might cost you a lot more if you have it customized however in your local industrial or engineering shop. Check out some good ideas in here and you can also ask their support if they can custom build one for you. http://www.alltimemed...l_Chair_For_Sale.html

[Rev. Green]

Many thanks Marc but the wheelchair is okay now. We had the footplate and the front wheels moved forward.
Wider wheels would not have helped. Think of a car with wide wheels, then move the rear axle forward a bit and move the front axle back until the front wheels almost touched the back wheels - the car would have been as unstable as wheelchairs are.
Interestingly, we saw old wheelchairs in a museum and they had large wheels at the front and small wheels at the back - a much better arrangement for covering rough ground. Present wheelchair manufacturers should be shot.