TOR for African bicycles 1985 - R.J.G. van Bergen

Terms of reference for an African Bicycle July 1985

R.J.G. van Bergen

Delft University of Technology

Terms of reference for African Bicycles

R.J.G. van Bergen

CICAT - CLT, in cooperation with Delft University of Technology, department Traffic

Stevinweg 1 2628 CN DELFT.

August 1985.

Index

1.

Introduction.

page.

1

2.

Conclusions following the Study.

page.

3

3.

Consideration pertaining to the options for use of the Bicycle

page.

8

9

in Africa, focussing on Tanzania.

3.1.

Topographical conditions.

page.

3.2.

Roads.

page. 10

3.3.

The situation of Traffic in general.

page. 11

3.4.

Goods to be transported with Bicycles.

page. 13

3.5.

State of art of Bicycles.

page. 14

3.6.

The condition of Bicycles.

page. 19

3.7.

Conclusions.

page. 27

4.

Terms of reference.

page. 31

4.1.

Objective.

page. 31

4.2.

Principals.

page. 31

4.3.

Preconditions.

page. 33

4.4.

Content of terms of reference.

page. 34

5.

Evaluation of terms of reference.

page. 43

- 1 –

1.

INTRODUCTION.

By comparing the transport situation in the Netherlands with that in African countries, the differences are enormous. All means of Transport in the Netherlands are motorised. Partly due to the good infrastructure, ample financial resources and good energy supply, an intricate and differentiated transport system has occurred.

In Africa, the transport situation is significantly worse. Virtually no infrastructure, limited financial resources and a scarce and expensive energy supply. Hence motorised transport is very expensive and therefore limited.

This has far-reaching consequences on many fields, such as distribution of raw materials, transportation of agricultural products and food distribution.

Especially concerning the latter aspect, there are many examples of a failing distribution of food for starving people in Africa.

Given the nature of the transportation problems simple solutions are desired, especially while the possibilities are limited. Therefore the bicycle might be a practical solution while it is a relatively simple and inexpensive means of transport. The bicycle is already used in many developing countries on a wide scale. The advantages of the bicycle are its simplicity. Low-cost and mainly the capability of transporting people and goods. Compared with walking it can carry 3 to 4 times over 5 to 6 times greater distances.

The bicycle is not always the most appropriate means of transport. There are many limitation of its use, such as Road safety, high purchase costs, theft, etc. The low bicycle use in African countries (especially compared with Asian countries) and the lack of attention by donor countries to transport and in particular to promote the use of bicycles, has been the start for the Centre for Low Cost Transport, CLT, to study the possibilities of the bicycle and cycling to improve the transport situation.

A close examination of the situation shows that various factors limit the use of bicycles, such as high acquisition costs, insecurity and the poor quality of the available material. Contacts with the Mission Action for Means of Transport, MIVA, Breda, one of the few organizations that offer solutions in

transportation in developing countries showed also there conclusion that there is a strong need for a bicycle, which is better adapted to the African - 2 -

situation. This has resulted in a joint study in Tanzania, (March 16-April 4 1985), with the aim to gather specific information for terms of reference for an African bicycle. In drawing up this list of requirements good use was made of already existing knowledge within CLT in bicycle technology in general and the situation in African countries in particular. In Chapter 2 the main conclusion from the study are indicated. Section 3 discusses the potential for bicycle use in African countries. The situation in Tanzania is taking as an example. In Chapter 4 the Operational Requirements for an African Bicycle are discussed in greater detail.

The ultimate goal of this project is the construction of an African bicycle (perhaps a few different models) which is then tested in the field. For now we see an important task for the Dutch bicycle industry in terms of design and manufacture of bicycles is. Ultimately we seek a situation where bicycles are manufactured locally. I think that this situation is only possible through a process of several intermediate steps, such as assembly, manufacturing of parts, etc. that will take some time. Involvement of all relevant agencies, governments and bicycle industry and certainly the people using the bicycle is a vital part. Finally it is important to mention that in the present report only a minor but important aspect is discussed of conditions to be met to make the introduction of the bicycle in African countries successful.

- 3 -

2. CONCLUSIONS FOLLOWING THE STUDY.

The activities in many areas in Tanzania have increased as a result of more opportunities to import, sell and buy goods, which affected also the field of small-scale industry and agriculture. That resulted e.g. in a greater need to transport goods, both in the rural areas as in cities.

As the possibilities for carrying goods on head, shoulders and / or back are very limited (up to 35 kg over limited distances) one looks for other means to transport goods in a simple way and cost effective way. The alternatives are very limited. In Urban areas there are some alternatives, such as wheelbarrows, handcarts, small and large motorised vehicles. These vehicles can be hired. Renting wheelbarrows or handcarts is not expensive. For motorised vehicles, the prices are high and not affordable for most people.

Therefore non-motorised transport is therefore used extensively.

- 4 -

fig. 3.

If, however goods are to be transported from urban to rural areas the costs will be high, at least with motorised means of transport. The non-motorised means are limited in terms of cargo and distances. The bus is an affordable alternative, for personal transport and small amounts of goods.

Hence the bicycle is intensively used on which daily trips of 50 km are be bridged. This includes not only personal transport, but also significantly for goods transport. The load on the bicycle during that goods transport is often quite high, up to about 100 kg. The above illustrates the need for freight on a small scale. The problems of transport by bicycle brings is very broad, including:

- Poor facilities on the bicycle for transport goods resulting loss of goods, - Overloading the bicycle, which costs more energy, intensive wear of parts resulting in reduction of the distances - The life cycle of the Indian and Chinese bicycles is limited thanks to the poor quality, which make the necessary cost of repairs and the large number of spare parts high.

- The poor state of roads in both rural and in urban areas is a danger to cyclists and causing technical problems with the bicycle resulting in restrictions of cycling.

- 5 -

I will discus the issues as mentioned above later extensively. There are other reasons to indicate that the widespread use of bicycles is hampered. The first obstacle of purchasing a bicycle is the price. That price has risen sharply in recent years and is subject to strong differences. In 1979 the price of a Chinese bicycle was 700, -. sh. (1 sh / fl O, 25), in 1984, prices were between 7000, -. and 10,000, -. sh. despite the official price of 2500, -. sh.

That price difference is an indication of the shortage of bicycles while there was a great demand. This year, the prices of bicycles significantly decreased, due to higher imports freedoms, which means a large number of Chinese bicycles had entered the country.

Officially bicycles are sold through the Regional

Trading Corporations, RTC. One must register and there are long waiting lists.

Unofficially bicycles are more expensive, but faster available.

As I mentioned earlier, the bicycle is a popular and useful means of transport. The limitations and shortcomings are unfortunately such that many people will not buy a bicycle. In discussions people made clear to me that they were willing to pay more for a better bicycle. Such a bicycle is currently not available.

The main technical limitations are in fact two points, namely

- Poor quality of the material, - Lack of knowledge regarding use, maintenance and repair of the bicycle.

The bicycles that are available in Tanzania are made of a lower quality than what is used in the Netherlands. Production techniques used in manufacturing bicycles in China and India are also of a non-comparable quality. Greater tolerances result in inaccurate connections and large clearances in parts.

Altogether this results in a product, which has a shorter life expectancy under the conditions in Tanzania.

- 6 -

The lack of knowledge about the use, maintenance and repair is due to the low level of education and totally different technological tradition, so any technical device which is introduced in the country, requires a certain adaptation of the users. Thus maintenance depends on preventive action.

Problems are prevented through regular maintenance. It appears that preventive thinking among users of bicycles is virtually absent. Due to the large number of bicycles, many repairer shops were set up by people without any specific education or with limited knowledge, mostly along the side of the road. As far as I have seen the quality of the repairs is moderate. Especially important repairs of the frame like welding are of such a quality that within a certain period it had to be repaired again.

The most significant repairs concern; - Flat tires, - Broken spokes, - Broken pedals, - Broken crank and cotter pins, - Broken bearings, - Broken chains - Broken front fork, - Frame cracks.

In Urban areas parts are pretty good available. The quality is poor and prices high. Repair men are found in the streets, usually near a spare parts shop, since they themselves have almost no parts in stock. Wide racks are specially made for transporting goods on a bicycle. Material used for repairing and for racks is primarily reinforcing bars. That results in a heavy but sturdy rack.

The more expensive racks are made of sheet metal, 1 mm thick, bent into a U shape. The many construction welding to both the series racks as the locally produced types, has quite a negative impact on the quality of the rack.

Given the large number of special racks it indicates that people still prefer such racks over the standard commercially available racks.

- 7 -

Local production of bicycles is a difficult matter. The most viable form of production is assembling imported parts. This production method is simple and can be implemented on a small scale. It concerns of the assembling of fully machined parts. This method is widely used in India by sending bicycles in crates to bicycle dealers who assemble on site.

The large-scale bicycle assembly factory in Dar Es Salaam, the National Bicycle Corporation, NBC, proved a failure. Reason for that failure was not the assembly, but management and a badly designed production line. The frequently heard view was that in small projects it worked well to guide the people and work resulting in products with reasonable to good quality. Large projects seem to be one step to far. Reasons are the lack of knowledge and experience to deal with large scale production and that workers are not used to work at assembly line. Small working groups, with a specific task under good supervision could produce good results. It is certainly important to take this into account, if a plan is made to set up an assembly line on any scale.

Another problem in manufacturing technical products is the supply of raw materials and components. That supply is mainly limited by the long supply lines and the effects of scarcity. Especially the latter is evident due to the many missing items during transport and in assembling. Components in high demand with high prices seem to disappear. The large number of different components is also problematic. Especially rural areas suffer from shortages of certain items, given the demand in the city and the long supply lines. An often expressed wish is therefore to reduce the number of different components. Standardisation of the components used seems to be a desirable development.

As a final point, certainly very important and not just for the bicycle, is the acquaintance with and knowledge of the techniques used in common and the bicycles in specific. Lack of training is the cause of unawareness of many technical options. In the Netherlands, for example, this is not a problem, while at school pupils are confronted at an early stage with different technical principles and solutions. Especially for bicycle specific components, such as a closed groove ball bearing or other parts, this is a handicap for a technician or components supplier. New structures or components have to be of a known and existing technical principle.

- 8 -

In discussions with technicians and people of workshops, the question was if they were interested in an especially newly developed transport bicycle, the Africa bicycle, to test it and set up an assembly plant. They showed great interest in a photo of a specially made transport bicycle as an example for a special bicycle. A hospital in Bukumi showed special interest for such a bicycle. They were willing to order several transport bicycles and test them to see if they could be used for transporting medicine and even patients.

Enthusiasm for a workshop in which bicycles were assembled was quite reluctant. The workshops were generally not equipped for assembling bicycles.

There was much interest in a strong durable bicycle, since they were convinced that the standard available bicycle was limited in use and carrying goods.

However, they were cautious.

3. CONSIDERATION OF OPTIONS FOR USE OF THE BICYCLE IN AFRICA, FOCUSING IN TANZANIA.

As far as possible during my trip I attempted to gather sufficient data to to give a clear picture of the situation in the areas visited during my trip. In addition to my own observation I had many interviews with users of the transport sector, residents and those who to lived and work in Tanzania for a long time knowing the situation and it’s potential. The following issues are discussed:

1. Topographic conditions.

2. Roads.

3. The situation of Traffic in general.

4. Goods, transported on bicycles.

5. State of the art of bicycles in use.

6. The condition of bicycles.

- 9 – 3.1. TOPOGRAPHICAL CONDITIONS

fig. 4.

Tanzania consists largely of a plateau. The terrain is also sloping, with low gradients. Areas with high altitude and steep slopes are mainly find in the West and South of the country.

The areas I visited were generally quite flat, excluding the area between Singida and Tabora, where high altitude and steep slopes occurred.

For motorised vehicles these conditions are not a major problem. For cyclists, by contrast, that height differences is indeed a barrier. Ramp rates of 2 to 5% are not a big problem, often with the help of others, who, together with the cyclist push it up the slope. Ramp rates above 5% are definitely a problem for a loaded bicycle. An empty bicycle could be pushed uphill. Given the state of the brakes on most bicycles downhill seems to me a very risky endeavour.

- 10 3.2. ROADS

fig. 5.

The main roads between major cities are not paved, with a few exceptions. The surface varies by region, but in general it is soft (sand or laterite).

Because of the many buses, heavy trucks and intense rainfall in the rainy season the roads are in bad shape. Deep ruts and potholes are not only inconvenient, including technical failures, but also result in severe accidents. Once a year Scrapers will level the surface, but the result is usually of short duration. In short, the road condition is a clear bottleneck in the transport sector for most of the means of transport in Tanzania.

In big cities, the roads and streets paved. Lack of maintenance resulting in pits and holes, which is highly obstructive for small-scale transport, like the bicycle, handcart and wheelbarrow. The sharp edges of pits cause many flat tires. In avoiding such pits dangerous situations arise, as motorised vehicles traffic gives no way to cyclists, resulting in many accidents.

- 11 -

3.3.

THE SITUATION OF TRAFFIC IN GENERAL.

The traffic situation varies greatly by region and city, depending on the population and activities. In rural areas buses, heavy and light trucks and passenger cars are used for long distance traffic. In and around the village’s bicycles, wheelbarrows and handcarts are used intensively. The bulk of goods to be transported are carried on head, shoulders and back.

There is much more variety of modes of transport and the traffic in Cities.

Heavy trucks, buses, cars, taxi’s and people with carts and wheelbarrows have to share the same road. There is no separation of different modes of transport. In the following list a distinction is made between different modes of transport and the intensity is indicated.

fig. 6.

- 12 Overview of the traffic intensity in 6 cities in Tanzania.

Cities Arusha

Nwanza

Tabora

Singida

Morogoro

Dar es Salaam

++

++

++

++

++

++

-

+/-

-

+/-

-

-

+/-

+/-

-

+/-

+/-

-

+

+

+

+

+

+

--

--

--

-

--

--

+/-

+/-

+/-

-

+/-

+/-

Busses

-

-

-

-

-

+/-

Trucks < 5 ton

-

-

--

-

-

-

Trucks > 5 ton

-

-

-

--

-

-

Means of Transport Walking

Wheelbarrow

Cart

Bicycles

Donkeys

Cars

Explanation of signs: ++: very much, +: much, +/-: occurs, -: minor, --: hardly any.

- 13 -

3.4. GOODS TO BE TRANSPORTED WITH BICYCLES.

Despite the great variety of goods and weight I have tried to give an impression of the nature and volume of goods transported in the following list. The weight of the goods is expressed in lower or higher than 50 kg.

Nature and weight of goods, which are transported with the bicycle.

Nature of transport

urban

rural

weight

++

+

+ 50 kg

Water

-

+/-

- 50 kg

Firewood

-

+/-

- 50 kg

Charcoal

-

+

- 50 kg

Agricultural products not processed

-

+

+ 50 kg

Bags of products

+

+

+ 50 kg

++

++

+ 50 kg

Building materials

+

-

-

50 kg

Hides

-

+

-

50 kg

Personal

Goods from an to the market

Explanation of signs: ++: very much, +: much, +/-: occurs, -: minor, --: hardly any.

- 14 -

3.5. STATE OF THE ART OF BICYCLES IN USE.

Below is an overview of the state of the art of bicycles, as in have seen in the areas I visited in Tanzania.

Type:

Size of Frame:

Gents model

predominantly

Ladies-, sports- and cargo model.

Low

22"

Predominantly

24"

Low

Smaller, or bigger than 22"/24".

Very low

- 15 Size of Tyres:

28" X 1½".

Predominantly Other sizes.

Type of Rim:

Westwood.

Size of Spoke:

Spoke 14.

Number of Spokes:

Front: 32 spokes.

Rear: 40 spokes.

Size front axle:

Size rear axle:

Length of crank:

7".

Very low

- 16 Chain size:

Teeth Chain ring:

48 teeth.

Teeth rear sprocket:

18 teeth.

fig. 15.

Chain guard

Fully chain guard

Low.

1/2 chain guard

Occurs.

No chain guard

Occurs.

fig. 16.

- 17 Brakes:

Handbrakes.

Rod control.

Stirrup braking system, brake shoes on the rim.

Seat

Leather saddle, with three-point spring suspension.

Mudguard

Usually present.

- 18 Rear rack:

Simple small rear rack.

Stand:

Sturdy stand near the rear wheel.

Predominantly.

Abnormal stand

Low.

Big headlamp and rear light

Occurs.

No lighting

Occurs.

Lighting:

- 19

-

3.6. THE CONDITION OF BICYCLES.

A great amount of bicycles is checked using a checklist resulting in a list in which the state of bicycles is reviewed. The list below is a summary thereof which in addition to an overall degree of occurrence low = -, Lots = + and an impression; good, moderate or poor with a brief explanation.

Part

Appreciation

Explanation

Bicycles

good

New bicycles, until 1 year old.

in general:

moderate +/-

Older than 1 year in bad state of maintenance.

inferior ++

Frame and wheels not in line. Bearings and brakes

--

not working. Still in use.

Frame.

Frame:

good

+/-

Paint disappeared frame in line, not repaired

moderate -

Frame not in line, crushed.

inferior +

Frame has been welded once or more, tubing buckled, influences way of driving.

goed

+/-

Lak verdwenen, frame in lijn, niet gerepareerd.

matig

-

Frame niet in lijn, gedeukt.

slecht

+

Frame op een of meerdere plaatsen gelast, knikken

Frontfork

in de buizen, be誰nvloedt rijgedrag.

- 20 -

Frontfork:

good

-

Original, paint disappeared.

moderate

-

Blades bended and/or crushed.

inferior

++ Crown and/or blades bent or welded, influences way of driving.

Soldered

Faulty Brake lever

Soldered

Poor braking pads

fig. 24.

Tyres

Tyres:

good

--

Some profile on the tyres.

moderate +/-

No profile, canvas is visible.

inferior ++

Cracks and ruptures in the tyres, pieces of tyre between tyre and inner tube.

- 21 -

Tyre ruptured

fig. 26.

Rims and

good

-

Original, spokes sometimes bent.

Spokes:

moderate +

Rim wobbles is crushed and spokes bent.

inferior +/-

Rupture in the rim, warped or repaired, spokes missing.

Wheel bearings, front and rear.

Wheel bearing good

-

Original state, minor clearance.

Front and

moderate +/-

Minor clearance. Dust caps gone.

Rear:

inferior +

Large clearance, missing balls, damaged axle.

- 22 Chain wheels.

Chain wheels

good

-

moderate +

Original, minor clearance, rusted.

Chain rusted, minor clearance, teeth of chain wheel bent.

inferior +/-

Large clearance of chain wheels, chain wheels welded, teeth worn out.

Bottom brackets and Pedals

Bottom

good

--

brackets and pedals

Original, minor clearance in trappers and crank fixing.

moderate +

Pedals gone, replaced by a wooden block, cranks not in line, cotter pins welded.

inferior +

Pedals gone, cranks welded, large clearance in bearings, bearing balls missing and bearing adjustment mechanism welded to frame.

- 23 -

Front and Rear brakes

Front and:

good

--

rear brakes

moderate +/-

Original.

Low braking force, reasonable clearance in braking operation, brake pads made of Car tyres.

inferior ++

No braking force, no brake pads, braking operation not working or gone.

fig. 31.

- 24 -

Handle bar

Handle bar:

good

+/-

moderate -

Original.

Bent, kinked, brake levers not connected to brake rods.

inferior +

Handle bar welded, kinked, connection of brake levers gone.

Handle bar bent

Left brake lever gone

Handle bar reinforced

fig. 33.

- 25 Saddle.

Saddle

good

-

Original.

moderate +

Leather top stretched.

inferior +/-

Leather torn, or gone, springs broken, fastening broken or welded.

Stretched saddle.

Locally made rack.

fig. 35.

- 26 -

Luggage carrier.

Luggage

good

+/-

carrier:

moderate ++

Original, of newly purchased.

Own model, self made rack, badly welded heavy material.

inferior --

Missing.

good

Original.

Mud guards.

Mud guard:

Lighting:

+/-

moderate -

Fixation loose, broken mud guards.

inferior +

Missing.

good

Original.

-

moderate ++

Lighting is functioning partly or not, but is not missing.

inferior --

Missing.

- 27 -

3.7. CONCLUSIONS.

Bicycles used in Tanzania are totally different from those used in the Netherlands. The way and intensity of use and conditions are clearly different. Below I give an overview of the main differences in the situations and circumstances between the Netherlands and Tanzania.

Netherlands

Bicycles:

Tanzania.

- Good quality.

- Reasonable to bad quality.

- Guarantee after sales.

- No guarantee.

- Good instructions for users. - No instruction for users.

- Adapted to personal wishes and sizes.

Users:

- Good knowledge of the bicycle and itâ&#x20AC;&#x2122;s use.

- Reasonable technical understanding.

- Fairly good maintenance.

- One size not adapted to personal wishes and size.

- Hardly any knowledge of the bicycle and itâ&#x20AC;&#x2122;s use.

- Hardly any technical understanding.

- No maintenance.

of the bicycle.

- Is fairly cautious with the

- Is not cautious.

bicycle.

- Will almost never overload causes the bicycle.

Roads.

- The need for transport overload of the bicycle.

- Major Road density.

- Minor road density.

- Excellent pavement, well

- Low pavement, poor

maintained.

maintained

- Hard surface.

- Soft surface.

- No Sharp obstacles on

- Sharp obstacles on the the

roads like stones etc.

- Good traffic facilities for bicycles.

roads.

- No traffic facilities.

- 28 -

Transport.

- Mainly personal transport.

- Personal but most transport of goods.

- Hardly any goods transport.

- Freights up to 100 kg.

- Sometimes a passenger.

- Very often passengers.

- Cheap and fast alternatives

- Expensive alternatives for

for goods transport.

Repairing.

- Very good repairing facilities in and around cities.

goods transport.

- In urban areas reasonable repairing facilities in rural areas hardly any.

- Good tools and repairing expertise.

Parts.

- Low quality tools and hardly any repairing expertise.

- Good quality.

- Low to bad quality.

- Easy to purchase.

- Not very easy to purchase.

- Reasonable prices.

- Expensive.

Legislation. - Requirements for

- No Legal requirements.

technical status.

- Legal status as a road user.

- No legal status as a road user.

The bicycles available in Tanzania are mainly produced in India and China. The technical status of those bicycles is based on an English design from the year 1930, Fig. 39. The construction and production techniques are often also hardly changed since then. Qualitatively, these bicycles are of a low quality, partly due to outdated technology and poor quality materials. Taking into account the poor conditions and intensive use the bicycles have a short life.

fig. 39.

- 29 -

To improve the life cycle and usefulness, a number of issues would need to be improved, namely:

1. Improving the conditions of use.

2. Improvement of traffic facilities.

3. Improvement of transport facilities with the bicycle.

4. Improving the quality of the bicycle and bicycle parts.

Ad 1.

Improving conditions on a short term is very hard to realise and is beyond the scope of this proposal.

Ad 2.

Improving traffic facilities on a short term is also very hard to realise although studies (see e.g. de Wilde [ref. 1.] and Halla, [ref. 2.] called for improvements. Proposals for this are beyond the scope of this proposal.

Ad 3.

The current bicycle is not very suitable for transporting goods not even with small improvements to the existing model. The construction and components used are not designed for this kind of use.

Ad 4.

Quality improvement is primarily a matter for the manufacturer of bicycles. It will be difficult to implement these improvements, since it has major consequences for the entire production.

My conclusion is therefore that a new type of bicycle should be developed, that::

1. Better adapted to conditions in Tanzania.

2. Is usable by both men and women.

3. Is more capable of carrying goods.

4. Having a better capacity for carrying big and heavy loads.

5. Having a long life expectancy for both the bicycle and components.

6. Makes maximum use of standard bicycle parts and existing bicycle techniques.

7. Easy to repair.

- 30 -

For clarity it should be noted, that the design is based on the existing situation. That situation is bad, as I have already stated, and should be improved. So the design will be a strong link in a weak chain. To optimize the use of bicycles, the previously mentioned problems should also be improved.

Based on the above conclusions a list of demands is drawn up to which the design of a new bicycle would have to comply, making them more suitable for the transport requirements and circumstances in Africa.

- 31 -

4. TERMS OF REFERENCE.

The terms of reference will be discussed as follows:

1. Objective.

2. Principles.

3. Preconditions.

4. Content of terms of reference.

4.1. OBJECTIVE.

As stated in the foregoing there is a strong need to design a solid bicycle.

The main objective is a bicycle, adapted to the given situation and use in Africa. In addition, the main criteria are:

- Simplicity.

- Sturdiness.

- Sustainability.

- Low costs for production, purchase, use and maintenance.

Secondary objectives include the ability to easily assemble the bicycle and its parts, since manufacturing in Africa is essential, including the possibility to use parts of the bicycle for

4.2. PRINCIPLES.

The circumstances of both roads and the traffic situation determines for a great deal the performance of the bicycle. The tires are taking the most important part because the roads are bad, having a soft surface and causing many flat tires mainly due to sharp objects. Big and wide tires are needed.

Furthermore, the transmission and gear reduction must have such a ratio that cycling will take the least possible effort to cycle on a soft surface and that small gradients are giving not too many problems.

- 32 -

Transport of goods is one of the main requirements which must be met by the bicycle. Because of stability problems, the freight must not be placed above the front wheel and preferably as low as possible. A good and stable solution is a large rack above and at each side of the rear wheel. That will hardly influence the stability and handling during cycling.

In some areas of Tanzania, both men and women wear long traditional dresses.

Cycling with such clothing on the men's model is very difficult if not impossible. The bicycle has to be designed in such a way that anyone with such a dress can ride the bicycle without too much trouble. The model that might meet the described demands, of usability and strength is called â&#x20AC;&#x153;mixedâ&#x20AC;? model in the Netherlands. It is by far the sturdiest model after the standard men's model.

The supply of parts in Tanzania is generally poor. In urban areas, the availability of parts is reasonably well, in rural areas very difficult. In addition, there are many different parts applied in the bicycle. Sometimes even some parts differ in size or versions. Not to mention the difference between the English and Metric sizes. That in turn determines the price of parts and repairs and at the end the usefulness of the bicycle. Hence standardisation is desirable.

Besides standardisation one of the secondary objectives is the possibility of using bicycle parts for other vehicles or applications. I am thinking of wheelchairs, hand carts, wheelbarrows, etc. By using the parts on a wider scale it will increase the availability and lower the price.

One of the main factors, which affects purchasing and use of the bicycle is the price. This price is primarily determined by the material, production methods and the production itself. Simplification of materials and production methods not only affect the price, but also the possibility for local assembly and production.

Although the use of standard bicycle parts is a starting point, no concessions should be made to the strength of certain components, for reasons of availability or application. This type of bicycle is designed as a model for performing a specific task, not as equivalent model of the existing bicycle.

Hence, certain components will have a different design. With great emphasis on a wide scale of usage of new parts, it will prevent, that certain items are not obtainable.

- 33 -

4.3. PRECONDITIONS.

Applied structures.

One of the main issues when introducing new tools and techniques is the knowledge of the principles and finishing of applied techniques. This knowledge might be based on traditional techniques, through training, or practical experience. If techniques are unknown, it will cause difficulties in operation and repair.

The bicycle is fairly well known in Tanzania and is also widely used. The users are therefore familiar with the basic techniques used with the bicycle.

However, if different structures and techniques are used in the bicycle, which are unknown to the users and repairers, it could cause problems with repairs and also the supply and delivery of parts.

Material weld ability.

The assumption that the frame is very strong and would have eternal life and therefore no fracture will occur is unrealistic. Hence, the possibility of repairing and even welding the frame is a realistic option. Fractures of the frame are often repaired using welding equipment, gas and electric. The frame material must be weld able. Another argument for the weld ability of the frame is the fact that people will adapt the frame to comply to personal use with racks of other means to make it more suitable to transport specific goods.

Wheels.

Wheels are ideal to use for in other means of transport. For example, bicycle wheels in many developing countries are used for hand carts and wheelbarrows.

In a standard bicycle a wheels will almost never take horizontal side forces.

The force is always vertical. If used on a cart, the wheel will often have to take horizontal forces. By using standard 28â&#x20AC;? bicycle wheels, the wheels have to be reinforced to take the horizontal forces. More spokes and wider hubs are necessary. This will make the wheel more robust than actually needed for the bicycle, but results in a longer life for a vulnerable part as is the wheel.

Also parts that are used on the standard bicycle use, such as lights, chain guards and mud guards, will also be used on the new bicycle. In addition, the possibility for local production of these parts will have to seriously regard while most of these parts are relatively easy to produce.

- 34 -

4.4. CONTENT OF TERMS OF REFERENCE.

Part

Finish

Motivation

Frame

Two models:

Two models are chosen while,

Gents model, "mixed" model. the Gents model is well known Both double tube frame.

and therefore more adaptable

Seat tube:

1 1/8"

and the â&#x20AC;&#x153;mixedâ&#x20AC;? model is the best

Down tube:

1 1/8"

option to use and transport goods.

Frame tube:

7/8"

This type of frame is light and can take Horizontal forces.

fig. 41.

fig. 40.

- 35 -

Wheels

Size of tyres 26" X 2"

This wide tyre can take heavy

36 spokes

loads, has a big surface area

spoke 11.

and therefore usable on soft surfaced roads. The spoke can take high tension.

Hubs

Wide hub and high flange

In using wide hubs, the Wheel can take Higher side (horizontal) loads but also higher horizontal loads

fig. 42.

Wheel

Adjustable conical bearings.

The bearings are of the same

bearings

1/4" balls.

construction as normal bearings,

Equal size for front and rear. but clearly bigger and therefore The bearing is equal to the

can take higher loads than the

bracket bearing, the Thompson

standard bearings. In using this

bearing type.

bearing for different options it is a standardised part.

- 36 -

fig. 43.

Front fork

Two straight tubes from the

This Construction is also used on

head tube to the front wheel

mopeds or motorcycles. It is

connection

simple and strong.

Tube: 1 1/8".

fig. 44.

Head tube

The head tube bearing is

This bearing is strong and simple.

equal to the bracket cups

Parts of the bearing are also

and balls. Only the axle

similar to the bracket bearing so

is different. The two

they are interchangeable.

tubes of the front fork are connected by two plates.

- 37 -

fig. 45.

Handle bar

Simple handlebar connected

By using this construction a

by two vertical tubes that

strong and Simple handle bar

fit into the front fork.

is realise that is Easy to

Tube size: 1".

Produce.

fig. 46.

Chain

Normal chain.

The standard chain is easy to

Chain size: 1/2" X 1/8".

purchase. By using a larger diameter chain wheel it can take higher loads or will last longer with the same load.

- 38 -

fig. 47.

Bottom

Thompson type. Adjustable

This Thompson type bearing is

bracket

bearing with cone and cups.

simple to adjust, to maintain

The cups are pressed in

and to repair.

the bracket tube.

The principle of the bearing

No thread has to be cut

is equal to the adjustable wheel

in the bracket tube

bearing.

like with the BSA type.

fig. 48.

Crank

Normal crank and pin

The standard crank connection by

connection

connection.

means of a cotter pin is good.

Diameter of pin: 12 mm.

The Bigger diameter of the pin results in a larger contact surface and firmer connection, compared to the cotter pin of 9 mm.

- 39 -

fig. 49.

Pedal

Rubber block containing two

A solid rubber block is stronger,

plastic bearing bushings.

can not fall apart and can take a

The crank is fitted with

beating. The two synthetic

standard thread FG 14.3 mm

bearings are probably less

left and right hand.

optimal than the conventional ball bearing type, but are less vulnerable and have a longer life span than standard pedals.

The standard thread allows it to Be used on standard bicycles, in case there are no pedals available.

fig. 50.

- 40 -

Crank

Normal crank length, 7".

The crank is of a heavy duty type

Heavy duty, extra thick.

especially the connection with the Cotter pin

dimensions.

crank.

fig. 51. fig. 51.

Chain wheel. Number of teeth: 52.

By using a larger diameter, the

Attachment to the crank

forces in the chain are smaller,

by means of a bolted and

resulting in a lower wearing.

pressed connection.

The direct connection with a bolt strengthens the attachment.

fig. 52.

- 41 Sprocket

Number of teeth: 22.

The gear ratio is 1 : 2,4.

Hand brakes.

Handbrake operation has certain

Calliper type at the front

advantages over a coaster, not as

and the rear.

prone to dust and easy to repair.

wheel

Brakes

fig. 53.

Saddle

Rack

Sturdy saddle with good

The leather of the current saddle

suspension.

is of a bad quality. Together with

Thick rubber saddle top.

the influence of the sun it will

Seat post: 1".

easily tear apart.

No rack at the front.

In transporting heavy cargo on the

At the rear two types of

front rack it will result in a

rack: A large horizontal

High centre of gravity and

rack, and a small horizontal

unstable steering on soft

rack and two Large racks on

surfaces.

both sides of the rear

The type of rack at the rear

wheel.

depends on the demand of what is to be transported. By placing the cargo On both sides of the rear wheel the centre of gravity is low resulting in a better stability.

- 42 -

fig. 54.

Stand

A sturdy stand.

A wide stand gives a greater stability especially when a load is placed on top or at the side racks.

fig. 55.

Lighting

Big reflectors.

Since the lighting system has a

At the front: White.

very short life span, big

At the rear: Red.

reflectors are enough to be seen in the darkness. The light is hardly used at night.

- 43 -

Mudguards

Wide simple mudguards, for

The material used is steel plate.

front and rear. Good solid

Production of mudguards is

connection to the frame.

relatively simple. For reason of standardisation the mudguards at the front and rear are equal.

5. EVALUATION OF THE TERMS OF REFERENCE.

The drawn up terms of reference(ToR), as previously stated, is based on existing knowledge within the CLT for use, conditions and performance of cycling in developing countries, together with findings gathered during the trip to Tanzania.

In preparing the terms of reference a number of criteria is used, namely;

- Simplicity of construction.

- Standardisation of materials and components.

- Easy to produce.

- Parts of the bicycle to be used in other vehicles.

- Capable of carrying goods.

- Sturdy construction.

- May be used by both men and women, or usable for persons with long robes.

- Low costs for both purchase, maintenance and repair.

In preparing the terms of reference a number of number of issues might have been overlooked, so the prototype might be differ from this report, like:

- Feasibility of the constructive execution.

- Way of production of some components.

- Price of production.

- 44 -

Adjustment of the terms of reference will be based on interviews with experts in construction and metalworking in the TH Delft, and experts in bicycle manufacturing. Manufacturing the first prototypes, 10 pieces, will take place in the Netherlands, so that specific technical know-how is used to optimize the bicycle.

Although local assembly is one of the objectives of this project in the preparation of the terms of reference adaptations will be taken into account, in favour of the assembly capabilities at a later stage be studied and implemented. This requires a detailed survey on the manufacturing capabilities on the ground.

CONSTRUCTION AND TESTING PROTOTYPE.

As already mentioned, the construction of the prototype will be executed in a Dutch bicycle factory. The specific knowledge is used to adapt the prototype to the best possible production methods. During this process special expertise in the field of development countries is needed during this process.

The prototypes will then be field tested on several aspects. These concern mainly the handling of the bicycle with and without any cargo on several road conditions. These characteristics will be of great importance for usefulness of bicycles in developing countries. Additionally, the bicycle will be tested on strength of the frame and the individual components. Very suitable for this purpose is an endurance test at TNO, an organisation that is specialised in testing means of transport. The bicycle is tested under load for a certain period on a test bench. After this first series of experiments in the Netherlands, field tests will be implemented.

The MIVA has the interest and intention to test the bicycles in their projects. While visiting Tanzania MIVA has confirmed this intention by employees, responsible for transport in a number of dioceses in Tanzania. The user will make an extensive report, accompanied by advice and recommendations for production in Tanzania.

- 45 -

So far the technical part. Another activity, which may be not overlooked, might be the presentation of the prototypes. A key party in the use of bicycles in developing countries is the Ministry of Development and in particular the Directorate General for International Cooperation (DGIS). Their function is the primary responsibility for implementing projects in developing countries.

The African bicycle will be presented to representatives of DGIS. The nongovernmental organizations will be approached to take note of this bicycle and use it in execution of their projects.

Presentation on a larger scale may take place in March 1986 at the big twoyear bicycle exposition in the RAl Amsterdam. This exhibition is always a big event for the national and international press. The author was interviewed in a TV show in 9 March 1984 on transport in developing countries and especially the role of bicycles. Reason was the participation of the Centre for Low-cost Transport in the bicycle exhibition.

It might be expected that the presentation of an African Bicycle, developed by the TH Delft in cooperation with the Dutch bicycle industry, will generate much interest in the media.

References:

[1]

Wilde, B.J. de "Low-cost transport for Developing Countries; Possibilities for the Bicycle in Tanzania" Centre for Low-cost Transport, CICAT Delft University of Technology, September 1983.

[2]

Ralla, F.F. "Bicycle Transportation in Dar es Salaam City: a feasibility study" Aidhi Institute, Dept. of Urban & Rural planning, Dar es Salaam, March 1981.