Author: Sam Brady, 26th November 2020

A really important factor to take into consideration when thinking about the technological development of sports wheelchairs – and wheelchairs generally – is what materials are used. In any design project, choosing a product’s composite materials is crucial. This can dictate anything from the ‘feel’ of the product and the end user experience, to production costs and manufacturing requirements. Historically, new materials have been introduced to alter various aspects of the wheelchair, but for sports wheelchairs, two aspects reign supreme; weight, and durability/rigidity. This blog post will take a brief look at these changes, as what a wheelchair is made of is just as important as how it used, or the shape it takes.

The weight factor is pretty straightforward: certain metals are heavier than others. So, in order to improve performance in sporting wheelchairs, lighter materials need to be identified. Originally, sports played as part of rehabilitation programmes at places like Stoke Mandeville made use of standard clinical wheelchairs – there was no such thing as a sports wheelchair at the time. These wheelchairs were often literal armchairs, like the Travaux, or were made almost entirely of tubular steel, like the Everest and Jennings folding wheelchairs.[1] Accordingly, these wheelchairs were heavy, weighing around 30lbs-40lbs, thus making the practicalities of fast-paced sport more difficult.[2] It should be noted, however, that these wheelchairs were massively improved compared to pre-1930s technology – which often weighed between 70lbs and 110lbs – but more refinement was necessary to arrive at the ultra-lightweight wheelchairs used today.[3] Many have acknowledged the importance of wheelchair sports to the development of ultra-lightweight wheelchairs, primarily due to the work of users who adapted their own equipment as manufacturers granted more importance to the voice of rehabilitation and medical professionals than those actually using the wheelchairs.

New metals were introduced to help reduce weight. Aluminium, for example, was experimented with by Bud Rumple and Joseph Jones in the early 1960s when they developed a rigid box frame that reduced weight by 10lbs.[4] By the 1990s, aluminium was one of two standard materials in sports chairs, particularly in racing wheelchairs – the other being chromoly steel, a chrome and steel alloy which is lighter and stronger than a carbon steel and offers similar advantages to aluminium.[5] Aluminium is a standard material to this day, due to its lightweight nature and low cost. This can be seen in an experimental table-tennis chair created this year, adapted primarily from a Quickie Q7, which is made from heat-treated aluminium.[6] Titanium was also utilised, despite the fact that it is slightly heavier than aluminium, as it is stronger in smaller quantities – making it very light overall.[7] This was experimented with in the 1990s, when Bob Hall worked with bike manufacturer Merlin Metalworks to create a titanium racing chair, which reduced weight down to only 12lbs.[8] Wheelchair manufacturing also took inspiration from other industries, such as bicycle engineering, and made use of similar materials – most notably Reynolds 531 tubing, a lightweight steel-alloy that was a bicycle industry standard for decades.[9] Finally, modern advancements have increased the usage of carbon fibre. For example, carbon fibre wheels and frames can be found in racing chairs such as the Top End Eliminator NRG, and custom moulded seats made from carbon fibre are found in basketball chairs such as the RGK Elite CX.[10] This can be prohibitively expensive, but also dramatically decreases the weight of a chair – perfect for maximising gains at the top level.

However the reduction of weight has an important impact outside of sport as well. As mentioned, modern ultra-lightweight wheelchairs owe their design largely to the sports wheelchair, as methods and materials used here were later evoked for the everyday design. This allows wheelchair users more independence and manoeuvrability, something that would not be possible with the heavy, medicalised wheelchairs of 100 years ago. Additionally, the ease with which  a material can be formed and shaped is significant when considering that many users customised or built their own chairs. Pre-formed materials like Reynolds biking tubing, for example, provided an advantage to those fabricating their own equipment, and explains the popularity of relatively cheaper lightweight materials such as aluminium, when titanium (and now carbon fibre) is considerably more expensive and difficult to work with.

Similarly, durability and rigidity are vital to retain the form of the chair, and to prevent injury of the athlete and breakdown of the equipment. In wheelchair basketball and rugby, for example, wheelchairs are constantly colliding with each other, so this factor also needs to be considered. After all, it makes no difference how light a chair is if it breaks easily. New materials are significant here, as whilst the steel used in earlier medicalised wheelchairs was robust, materials such as aluminium and titanium maintained this strength whilst also being significantly lighter.[11] However, this also had a lot to do with the shape and form of new chair designs, such as the aforementioned aluminium box frame created by Rumple and Jones. 

Ultimately, which materials are used when creating a wheelchair is important, but this still remains far from the only defining factor in creating an efficient and effective sports wheelchair. The shape of the chair can make a fundamental change to performance, such as in the shift from four wheels to three wheels in wheelchair racing. As well, the custom fit of a chair to the user makes a considerable difference – today, any elite level sports wheelchair will be customised to its user, and this advantage works in tandem with weight and shape to maximise efficiency. Furthermore, the addition of strapping in sports like basketball help to reduce injury beyond what durability can achieve. Vitally, this can be seen back in the early days of wheelchair sport design – in the 1960s, wheelchair basketball players first achieved weight reduction by removing unnecessary parts – e.g. armrests and breaks – and by altering key design elements, such as using a box frame instead of a folding frame, which also increased the rigidity of the chair during play.[12] It was not simply the material change that helped to decrease weight and increase rigidity, but the combination of new materials with a myriad of other factors. This underlines the complexity and ingenuity of sports wheelchair design, as often one factor alone is not individually responsible for changes in weight, performance or fit.

The change in materials used in sports wheelchairs in many ways mirrors the evolution of the sport from a rehabilitation tool to a user led industry, and now to a highly competitive and technologically advanced sport. Whilst the materials utilised are not the only important factor in improved wheelchair design and development, it is nonetheless a key factor in the history of the sports wheelchair.

[1] ‘Sports Wheelchairs in the 1980s: The Impact of New Designs and Materials’, Mandeville Legacy, 2011. http://www.mandevillelegacy.org.uk/page_id__37.aspx?path=0p4p14p22p
[2] Stewart and Watson, ‘A Sociotechnical History of the Ultralightweight Wheelchair: A Vehicle of Social Change’, Science, Technology, & Human Values, 44.6 (2019), p. 6.
[3] Stewart and Watson, p. 6.
[4] Ibid, p. 13.
[5] Cooper, ‘Wheelchair Racing Sports Science: A Review’, Journal of Rehabilitation Research and Development Vol, 27.3 (1990), p. 6. /  ‘What Makes A Chromoly Bike Better?’, Detroit Bikes, 2018. https://detroitbikes.com/blogs/the-bike-blog/what-makes-a-chromoly-bike-better
[6] Quickie Q7 - https://www.sunrisemedical.com/manual-wheelchairs/quickie/rigid-wheelchairs/q7  /  Duvall et al, ‘Design of an Adjustable Wheelchair for Table Tennis Participation’, Disability and Rehabilitation: Assistive Technology, 0.0 (2020), p. 4.
[7] Cheng, Arnold, ‘Manual Wheelchairs Are Not All Created Equal’, Rick Hansen Foundation, 2015. https://www.rickhansen.com/news-stories/blog/manual-wheelchairs-are-not-all-created-equal
[8] Vandermark, ‘Wheelchair Design: Race Version’, 25Seven, 2008. https://construct.typepad.com/25seven/2008/11/wheelchair-design-race-version.html
[9] Sports Wheelchairs in the 1980s - http://www.mandevillelegacy.org.uk/page_id__37.aspx?path=0p4p14p22
[10] RGK Elite CX - https://rgkwheelchairs.com/wheelchairs/sport-wheelchairs/elite-cx.html  /  Top End Eliminator™ NRG Racing WheelChair - https://topendwheelchair.invacare.com/eliminatorNRG
[11] Stewart and Watson, p. 15.  /  Vandermark - https://construct.typepad.com/25seven/2008/11/wheelchair-design-race-version.html
[12] Stewart and Watson, p. 12.

Reading list:

• Cheng, Arnold, ‘Manual Wheelchairs Are Not All Created Equal’, Rick Hansen Foundation, 2015. https://www.rickhansen.com/news-stories/blog/manual-wheelchairs-are-not-all-created-equal
• Cooper, Rory A., ‘Wheelchair Racing Sports Science: A Review’, Journal of Rehabilitation Research and Development Vol, 27.3 (1990)
• Duvall, Jonathan, Benjamin Gebrosky, Jeffrey Ruffing, Aaron Anderson, Siew Seang Ong, Robert McDonough, and others, ‘Design of an Adjustable Wheelchair for Table Tennis Participation’, Disability and Rehabilitation: Assistive Technology, 0.0 (2020)
• Quickie Q7, Sunrise Medical https://www.sunrisemedical.com/manual-wheelchairs/quickie/rigid-wheelchairs/q7
• RGK Elite CX, RGK Wheelchairs https://rgkwheelchairs.com/wheelchairs/sport-wheelchairs/elite-cx.html
• ‘Sports Wheelchairs in the 1980s: The Impact of New Designs and Materials’, Mandeville Legacy, 2011. http://www.mandevillelegacy.org.uk/page_id__37.aspx?path=0p4p14p22p
• Stewart, Hilary, and Nick Watson, ‘A Sociotechnical History of the Ultralightweight Wheelchair: A Vehicle of Social Change’, Science, Technology, & Human Values, 44.6 (2019)
• Top End Eliminator™ NRG Racing WheelChair, Top End. https://topendwheelchair.invacare.com/eliminatorNRG
• Vandermark, Rob, ‘Wheelchair Design: Race Version’, 25Seven, 2008. https://construct.typepad.com/25seven/2008/11/wheelchair-design-race-version.html
• ‘What Makes A Chromoly Bike Better?’, Detroit Bikes, 2018. https://detroitbikes.com/blogs/the-bike-blog/what-makes-a-chromoly-bike-better