BICYCLE TRAILERS
Introduction
In many developing countries people live in regions away from the main transport infrastructure. This means transport services are expensive Many villages in the South are not part of road networks and the lack of transport is a constraint on income generating activities such as taking produce to markets and acquiring equipment and materials needed for a small enterprise The approach of Practical Action is to promote a view of transport systems that addresses problems of access and mobility for rural people Strengthen capacity of communities to control & manage transport facilities Practical Action has worked on a Figure 1: Piyasena uses his cycle trailer as a mobile range of transport technologies mini store and kitchen. Hambamtota District, Sri Lanka. that address different transport ©Zul/Practical Action needs, such as Ox carts, extended load carrying bicycles, aerial runways, bicycle taxis, bicycle ambulances, wheelbarrows, low cost wheelmaking, animal harnesses, low cost road construction and bicycle trailers. Cycle trailers are used for transporting goods, fuel, water and harvests where other means are too expensive Trailers allow people can now carry three times as much as with a bicycle, which allows people to carry around 200 kilograms (450 lbs.) The range of use is quite wide including ambulances, mobile shops, and even a mobile library in one instance in Sri Lanka, shown in figure 2. Bicycle trailers Bicycle trailers were developed within Practical Action South Asia (Sri Lanka) then adopted by Practical Action East Africa (Kenya) and now in Nepal and Zimbabwe.
Figure 2: A cycle trailer used as a mobile library for school children in Sri Lanka
©Zul/Practical Action
Practical Action, The Schumacher Centre for Technology and Development, Bourton on Dunsmore, Rugby, Warwickshire, CV23 9QZ, UK T +44 (0)1926 634400 | F +44 (0)1926 634401 | E infoserv@practicalaction.org.uk | W www.practicalaction.org ______________________________________________________________________________________________ Practical Action is a registered charity and company limited by guarantee. Company Reg. No. 871954, England | Reg. Charity No.247257 | VAT No. 880 9924 76 | Patron HRH The Prince of Wales, KG, KT, GCB
Bicycle trailers
Practical Action
To make sure that the cycle trailer are affordable, Practical Action works with local partner organisations who operate credit schemes at low interest rates.
How to make a bicycle trailer
The cycle trailers are made in small village workshops from iron tubing, which is cut, bent, welded and drilled to make the frame and wheels. Modifications are also carried out to the trailers in these workshops at the request of the buyers.
Figure 3 shows one of the designs produced by Practical Action The frame needs to be strong and rigid but as light as possible. Thin wall tube gives the best design but is not always available or affordable and some skill is needed to weld the thin material.
50.8 mm square wire mesh
Details of the Frame Construction
Figure 4: The frame construction is made up from welded steel tube .
Bicycle trailers
Practical Action
The component parts to the frame design are listed in table 1
Part No 1 2 3 4 5 6 7 8 9 10 11 12 Description Round Tube Square Tube Square Tube Square Tube Square Tube Square Tube ‘∟’ Angle Rod Wheel Mounting Plank Hitch (Male) Round Tube Qty 1 2 5 6 4 2 6 2 4 2 1 1 Material Mild Steel Mild Steel Mild Steel Mild Steel Mild Steel Mild Steel Mild Steel Mild Steel Mild Steel Wood Mild Steel Mild Steel Semi Finished Dimensions ○ 19.05 x 2713 □ 19.05 x 914 □ 19.05 x 623 □ 19.05 x 382 □ 19.05 x 877 □ 19.05 x 445 ∟ 19.05 x 19.05 x 125 ● 09 x 240 ▬ 50.8 x 50.8 x 6.35 873 x 126 x 15 ○ 19.05 x 560
Table 1: Parts list for the bicycle trailer frame.
Steel or rubber ball
Alternative frame constructions can be used depending on materials and the production equipment available.
Frame made from round tube Figure 5 shows an alternative frame Minimum size design made from tubular bar. 22 x 1.5 Preferred size 25 x 1.5
Reinforced inside of joint with a piece of tube or bar
Round bar
Base frame and corner posts 25x25x3 angle
Figure 6 shows a frame that can be made from angle and bar
Round bar
Box section made from angle
Flat bar
Bicycle trailers
Practical Action
Hitch Although hitching the trailer at the level of the rear axle has the least effect on the stability of the bicycle, hitching above the rear wheel. (to the carrier or to the frame below the seat) is simpler and more compatible with duel use of the trailer as a handcart. This method has been widely tested on earth roads and tracks in various countries and has caused no problems for the trailer users. Various hitch mechanisms may be used, the requirement being that they are strong and durable and do not constrain relative movement between the bicycle and the trailer. The recommended mechanism is a rubber ball in a steel socket attached to the carrier or the rear wheel stays, but in some cases, the trailer has simply been tied to the carrier. Wheels Normal bicycle wheels are suitable for light loads on good roads but are not robust enough for carrying heavy loads or for use on rough tracks. Strengthened wheels that take standard bicycle tyres have been developed for trailers.
Figure 7: Hitch design. A stee or rubber ball drops into a socket formed from flat bar or cut from a pipe bolted to the carrier or frame of the bicycle
References and further reading
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The Design of Bicycle Trailers Michael Ayre IT Publications 1986 Low-cost Load-carrying Devices: The Design & Manufacture of Some Basic Means of Transport Ron Dennis and Alan Smith ITDG Publishing 1995 Puncture Prevention Techniques for Low Cost Vehicles Michael Ayre & Alan Smith Cycle Trailers for India. Appropriate Technology Vol. 18 No 2 Forum News. The International Forum for Rural Transport and Development
A quarterly newsletter looking at the issues of transport with animal power, bridges, bicycles, gender and transport, financing, engineering, sustainable rural livelihoods, community planning. IFRTD’s address is shown below.
Useful contacts
I. T. Transport is a consultancy in transport for rural development. I.T. Transport Ltd. The Old Power Station Ardington, Nr. Wantage Oxon OX12 8QJ United Kingdom Tel: +44 1235 833753 /821366 Fax: +44 1235 833753/821366 E-mail: itt@ittransport.co.uk Website: http://www.ittransport.co.uk/
Bicycle trailers
Practical Action
The International Forum for Rural Transport and Development is a global network of individuals and representatives from government, academia, multilateral and bilateral donor agencies, consultancies and technical institutions, national and international NGOs and groups of community organisations in 83 countries in Africa, Asia, Europe and North and South America. IFRTD Secretariat 2 Spitfire Studios 63-71 Collier Street London, N1 9BE United Kingdom Tel: 44 20 7713-6699 Fax: 44 20 7713-8290 E-mail: ifrtd@gn.apc.org Website: http://ifrtd.gn.apc.org/
Internet addresses
World Bank http://www.worldbank.org/html/fpd/transport/rural_tr/rts_imt.htm#patterns The DFID transport site is managed by TRL (Transport Research Laboratory). www.transport-links.org
Practical Action The Schumacher Centre for Technology and Development Bourton-on-Dunsmore Rugby, Warwickshire, CV23 9QZ United Kingdom Tel: +44 (0)1926 634400 Fax: +44 (0)1926 634401 E-mail: inforserv@practicalaction.org.uk Website: http://practicalaction.org/practicalanswers/
Practical Action is a development charity with a difference. We know the simplest ideas can have the most profound, life-changing effect on poor people across the world. For over 40 years, we have been working closely with some of the world’s poorest people - using simple technology to fight poverty and transform their lives for the better. We currently work in 15 countries in Africa, South Asia and Latin America.
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