Wheelchairs have rapidly evolved in recent years. Just a decade ago, the world's lightest wheelchairs were in the range of 10kg (approximately 22lbs). Now, it is possible to find ultra-lightweight wheelchairs in the range of 5 kg (approximately 11 Kg) or less including wheels. These new ultra lightweight wheelchairs are possible due to advances in materials, technology and designs.
What is the advantage of an ultra lightweight wheelchair?
There are three advantages to an ultra lightweight wheelchair:
* Transfers and Travel: An ultra-lightweight wheelchair simplifies traveling. Getting into a vehicle is much easier if your wheelchair weighs 5kg instead of 10kg. Many wheelchair users get into a car alone, reach out and pick up the wheelchair and pull it in. This complicated maneuver is considerably easier if the wheelchair frame is a feather light 2 or 3 kg, rather than a clunky 7 or 10kg.
* Performance: An ultra-lightweight wheelchair is easier to push. For example, some wheelchair ramps can be steep. Pushing yourself up a ramp in a wheelchair which weighs 5 kg is much easier than in an old-fashioned heavy wheelchair which can weigh anywhere from 5-15 KG more.
* Cool factor: If you have to be in a wheelchair, it is best to be in the coolest, lightest, most innovative wheelchair possible.
What is the best material for an ultra-lightweight Wheelchair?
Which is the best material for an ultra-lightweight wheelchair is an impossible question to answer. Ultra-lightweight wheelchairs are typically made of four types of materials: aluminium, titanium, carbon fiber and other composite materials. Comparing one type of material to the other is made nearly impossible since each type of material has advantages and disadvantages and technology is constantly advancing. For example just ten years ago carbon fiber was known for yellowing and breaking. But with improved technology, the best carbon fibers of today have come a long way from the carbon fiber wheelchairs of a decade ago. Many composite materials are a combination of carbon fiber and plastics or resins and these too have come a long way in recent years.
As an example, the aerospace industry is on the cutting edge for creating strong and lightweight materials, for a simple reason. The lighter the aircraft, the better it will perform and the more fuel efficient it will be. Boeing states that its new 787 Dreamliner "is the company's most fuel-efficient airliner and the world's first major airliner to use composite materials for most of its construction" According to the Boeing website the new design has "an airframe comprising nearly half carbon fiber reinforced plastic and other composites. This approach offers weight savings on average of 20 percent compared to more conventional aluminum designs". While most wheelchair manufacturers will make a wheelchair from either aluminum, titanium or composites, Boeing takes advantage of all of these materials and uses them appropriately to achieve the lightest and safest airplane possible.
Engineering is more important than material
Further, not all aluminum wheelchairs or titanium wheelchairs are equal. There are so many factors which go into making the frame that an aluminum wheelchair made by one company may easily be lighter than a titanium wheelchair from another company and vice versa. Tubing diameter and wall thickness effect stiffness, strength and weight. One manufacturer could use a thin walled tubing and achieve a lightweight frame which would be very satisfactory for some users, but which could crack under heavier strain from other users. The lightest wheelchairs will employ various thickness and diameter tubing in different parts of the frame in order to achieve the best balance of weight, strength and stiffness necessary for the best ride.
For example, titanium has a higher strength to weigh ratio than aluminum. But in 2008 researchers from the Veterans Administration and University of Pittsburgh published a study of tests on four popular brands of titanium wheelchairs. The scientists found that the titanium wheelchairs that they tested failed quicker than aluminum wheelchairs that they had previously tested. These wheelchairs were lightweight, but apparently some of the lightness may have been achieved at the sacrifice of frame strength.
Therefore, it is mistake to assume that a wheelchair made of a particular material is necessarily going to be lighter, stronger or better than a wheelchair made of a different type of material. The lightest weight and strongest wheelchair of the future will probably be one which uses a combination of different types of materials as in the Boeing Dreamliner.
Some issues to consider about all types of materials
Titanium: Titanium can be difficult to paint. Special painting techniques may be employed, but they are often costly. As a result, many titanium wheelchairs are a dull grey color. Some like it and others do not.
Carbon-Fiber: While improving, there are still complaints about carbon fiber frames breaking. Whether or not the technology is mature enough will most likely depend on the type of carbon fiber processes that your manufacturer is using. Also carbon fiber may yellow when exposed to UV light, unless coated with paint or some other material.
Aluminum: Welded aluminum frames are generally going to be lighter than aluminum frames held together with brackets and screws. But many people do not like the looks of welding on wheelchairs and welding renders the wheelchair non-adjustable. If you want to sell your wheelchair, you may have a problem finding a buyer who is exactly the same size as you.
How Does The Wheelchair Fit?
One of the key issues in selecting an ultralight wheelchair is how the manufacturer makes it fit your body. There are typically three approaches:
* Adjustability Approach: A manufacturer may make a wheelchair with a few frame lengths and widths then use adjustability to make it fit your particular dimensions and requirements. They will adjust the front seat height, rear seat height, front caster angle, back rest angle, backrest height, foot rest length to fit your requirements. The problem is that adjustability requires bolts, brackets and screws and these add weight to the wheelchair. Most ultra, ultra-lightweight wheelchairs will have limited adjustability.
* Fixed Frame Dimensions Approach: Some manufacturers may save weight by having little or no adjustability and have simply have a "few sizes fits all" approach. In order to minimize the number of frame sizes that they must keep in stock, they may try to minimize some dimensions. For example, some wheelchairs may be offered in only 1 frame lengths and recommend that everyone, from very short to very tall fit in a wheelchair frame of the same length.
* Custom Approach: Customization means that the wheelchair is built from the beginning to the exact dimensions of the buyer. This has the advantage that a fully customized wheelchair will fit the owner's body perfectly. With no adjustability required, a customized wheelchair has fewer bolts, brackets and screws and is therefore lighter. The disadvantage of a customized wheelchair is that if the measurements are wrong, the wheelchair must be made again. If you are not comfortable the manufacturer may not be willing to build you a new wheelchair. The other disadvantage is that if you ever want to sell the wheelchair it can be very difficult to find a buyer who has the exact dimensions and requirements that you have.
Wheelchair Weight, Comparing Apples to Oranges
Which manufacturer makes the world's lightest wheelchair?
This is probably not as easy to answer as you might think. Many factors will play a role in a wheelchair's weight and finding the data necessary to compare weights is often an impossible task.
Many manufacturers will give the weights of their wheelchair frames without wheels, locks, side guards, even upholstery. Other manufacturers will include these or other parts. The same frame might come with several sizes or configurations. If wheels are included, the type of wheels can play a significant role. Rear wheels often add 2kg or more to the weight of the wheelchair. Rarely does a manufacturer give the specifications of the conditions under which it was weighed. Rarely do they tell you the frame size or wheel type or used during the weighing. Therefore, making a comparison of weights of one wheelchair to the next will be very difficult to do and the weights given below should be used as an indication. Do not use these weights to compare one wheelchair to the next, but rather to get an idea of how light a wheelchair can be.
The World's Lightest Wheelchairs
If you are looking for the world's lightest wheelchair, here are a few to consider.
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