The new design aims to cost approximately / of the current cheapest handcycles available in Australia, while retaining all of their features and more. This would be of great benefit to Australian cyclists, and has potential for worldwide impact, as cheap alternatives to current technologies are in demand in developing countries.
Handcycles have been used for hundreds of years as an alternative to wheelchairs, hand cranks can be attached to wheelchairs, or exist as a stand-alone unit. They can be electrically powered, have full suspension for mountain riding, or exotic composite parts and high tech accessories for racing. As well as useful and fun, many studies have shown that handcycles are more efficient than wheelchairs, less physiologically straining, and can be used by wheelchair users to cross train, improving their wheelchair performance.
Appropriate technology means technology that is appropriate for the context in which it is used, which usually means it is sustainable – i.e. requiring few resources and producing less pollution than other available alternatives, as well as typically being decentralised, small scale and locally controlled.
In the context of handcycles, which are typically used by people suffering from spinal cord injuries, making them unable to ride standard bikes, the use of appropriate technology is especially important.
For my project, this means using scrap bikes for prototyping on a tight budget. Prototypes can be developed and refined using old parts at very little cost, and then the design can be adapted to be manufactured from scratch using modern manufacturing techniques. Design for manufacture and assembly principles play into the design – reducing the total number of parts used in the bike, by using standard parts –for example using only one or two standard pipe diameters, if screws or bolts are needed, use as few types as possible.
The cost of current handcycles ($ – $,) is high due to their heavy reliance on custom parts and relatively small scale manufacturing. This is exacerbated in Australia by the lack of Australian handcycle manufacturers, forcing buyers to import them. Medical insurance coverage also adds to the problem, as handcycles are generally not covered by insurance as they are not “medically necessary”, meaning generally no assistance is possible.
Talks with the users revealed that, above cost, the principle issue was ease of use. If it was too hard to get into the bike (transfer), especially by one’s self, or if it was hard to use, it simply wouldn’t be used. Therefore the most critical consideration is looking at the context of the design. For this project, this was done firstly through research of handcycles currently available, finding areas in which current designs were particularly weak, talking with users of handcycles, and reading forums online that concerned handcycles.
Ease of use is critical – even if all the parts are perfectly positioned to maximise mechanical efficiency and minimise physiological strain, it won’t matter if the cyclist can’t get in the bike, or it’s so hard to get in, they can’t be bothered. No handcycle that I have seen has included much help in this respect. One of the biggest issues seems to be the difference in height between the seat of the wheelchair and the bike.
The first handcycle prototype is nearly completed, and testing will begin soon. A second, optimised prototype will be developed later this year, considering outcomes from the first prototype, computer simulations, and input from handcycle uses. A costing exercise will be performed after this, involving a comparison of different costing models and materials. The publication of these findings will hopefully encourage more research and development in this field, and pave the way for the development of both cheaper and easier to use handcycles.
Tim Fraser is in his final year at RMIT, studying Mechanical Engineering and a Diploma of Languages. He is working on the EWB Humanitarian Engineering Research Program this year. He is interested in mechanical design and computer aided design, and is looking forward to finishing up his studies and travelling at the end of this year. As part of EWB’s Research Program he is researching new designs to make handcycles more affordable.
Photos:Top left- Tim testing the Hancycles at Melbourne Disability Sport and RecreationTop right- the first prototype, ready to be weldedBottom left- cutting up old bike frames to build the first prototype