Tricycle Production Manual - Vehicle design for people with disabilites in developing countries

The tricycle is designed primarily for disabled people in Asia, since the result is a joint effort between four Asian organizations. The Tricycle Production Manual has been developed for basically skilled and equipped workshops in developing countries. Internet publication URL:

by I. Oldenkamp, Industrial Design Engineering, Delft University of Technology

(Permission has been kindly given by I. Oldenkamp, Industrial Design Engineering, Delft University of Technology to allow the Independent Living Institute to present this excert from the Tricycle Production Manual.)

The Tricycle Production Manual has been developed for basically skilled and equipped workshops in developing countries. The manual is, as much as possible, adjusted to the knowledge and experience of workshop workers in these countries. It contains mostly drawings and minimal text to keep the manual accessible to a large group of users.

The first part gives relevant information on tricycle design. The second part is a step-by-step guide to the production of the tricycle. The tricycle production is explained by means of three dimensional drawings and additionally supported by two-dimensional drawings. Measurements are limited to those which are strictly necessary for the drawings to be easily understood. Pictograms are used to indicate the production steps and actions. The structure and lay-out of the manual is clear and practical. The third part gives some ideas about additional features for the tricycle. The fourth part contains extra useful information and alternatives for production. The fifth and last part contains some relevant background information

The tricycle

Who is the tricycle for?
The tricycle is designed primarily for disabled people in Asia, since the result is a joint effort between four Asian organizations. However the tricycle design is also meant for disabled people and their producers in other comparable parts of the world. The tricycle is suitable for disabled people who cannot walk but can use both arms. These users may have lost their mobility by an accident and have a leg amputation or are paralyzed. With the tricycle they have the possibility to travel independently and seek work, sell tickets or transport goods. The measurements (seat, footrest adjustment and propulsion mechanism) of this design are based on persons with a body-length of 1.50 meter up to 1.75 meter. For users who do not fit into this group the measurements should be checked and, if necessary, adjusted.

Why this particular tricycle design?
There are many different tricycles in the world. Some have problems with stability while others are not comfortable or are difficult to produce. In this tricycle design, requirements concerning production, distribution and use have been taken into account as much as possible.

The most important requirements were:

  • Stability
    The stability of the tricycle is very important for the safety of the user. This can be achieved by making the wheelbase wide enough and the center of gravity as low as possible but limited by the space needed for the legs of the user.


  • Driving comfort
    The correct position of the propulsion handles is necessary for easy and comfortable driving. The propulsion mechanism has been made adjustable to accommodate the different arm lengths of users. The gear-ratio of the freewheels is 1:1. This ratio is selected to provide comfortable driving under average road conditions. In hilly places the freewheel of the front wheel should be larger than the freewheel at the propulsion handles.


  • Weight
    Many existing tricycles are very heavy (more than 40 kg) which makes them difficult to drive. Due to the asymmetrical construction of this tricycle design, the weight is relatively low; around 30 kg.


  • Sitting comfort
    The sitting comfort is important, especially for disabled people who have to sit for long periods of time. If the pressure on the buttocks is too high (due to a bad surface or a footrest which is too high) the blood circulation will be bad. For a comfortable seat the following dimensions are important: seat-depth, seat-width, back-height, armrest-height and footrest-height. The footrest is adjustable to the individual user. Cushions are important to avoid pressure sores on the driver's buttocks and springs will absorb shocks during driving.


  • Production
    The tricycle can be produced with basic tools and locally available materials. The measurement tolerances are made as large as possible to avoid production and assembly problems. Jigs and fixtures are not included in this manual. General designs cannot be given since they very much depend on locally available materials. Nevertheless the use of jigs and fixtures is strongly recommended.


  • Costs
    Costs depend highly on local circumstances; material costs, labor costs, number of tricycles in the series, etc. They are intended, however, to be kept as low as possible.


Background of the manual

How was the manual achieved?
The Tricycle Production Manual was part of the project Development of Tricycle Production in Developing Countries (DTP-project), October 1992 - May 1995.

Who contributed to the DTP project?
The project was financed by the Swedish International Development Agency (SIDA) through the Swedish Organization of Handicapped International Aid Foundation (SHIA) and supported by the Swedish Association of Persons disabled by Accidents or by Polio (RTP) and the Swedish Federation of Disabled Persons (DHR). The project was initiated and coordinated by the Center for International Cooperation and Appropriate Technology (CICAT) at the Delft University of Technology (DUT) in the Netherlands. The project has been carried out by the Faculty of Industrial Design Engineering (FIDE) in close cooperation with the following mobility aids producing organizations: Workshop for Rehabilitation and Training of the Handicapped (WORTH) in India; Sarvodaya Economic Enterprise Development Services (SEEDS} in Sri Lanka; McKean Rehabilitation Center (MRC) in Thailand and Bavi Orthopedic Workshop (BOW) in Vietnam. During a period of two years a project-engineer, the manager (or designer) of the tricycle workshop and two technicians from each organization worked for the DTP-project. They collected information, carried out user tests, designed parts or completely new tricycles, built prototypes and optimized the tricycle production. They also participated in the seminars and workshops held respectively in Thailand, the Netherlands, India and Sri Lanka and they participated in a design training in Thailand organized by CICAT/FIDE in cooperation with the Chiang Mai University (Chiang Mai, Thailand).

The Tricycle Production Manual was written by:
Annemiek van Boeijen
Paul Flier
Ingo Oldenkamp
Oscar Toetenel
Ruud Vermeulen
Joep Verweij

For more information please contact:

Faculty of Industrial Design Engineering

Jaffalaan 9
2628 BX Delft
The Netherlands