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Load rack for bicycles, to be made on the spot: Requirements for the design of a brake for a bicycle
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Requirements for the design of a brake for a bicycle
Bike-brake in third world countries
In countries where people have little money, bicycles give some independance with the transport of people and goods. These bikes will ride bumpy roads, and will be heavily loaded especially with the heavy-duty load rack attached. For a safe use, a good brake is a necessity.
Of course the bicycle involved came from the factory with a set of brakes. Our observation is that on older bicycles such brakes do not function any more and the brakes can not be repaired while crucial parts have broken off.
Analysis
Target group: A solution is sought for a market salesman who will transport his merchandise by bike from his personal spot to the place to sell it. Possibly such a solution can also be used for a bike for transport of people, for instance a rickshaw. The market salesman needs his bike for his daily income and is therefore anxious to keep his bike and brake in a good shape. He can pay a little money to the brake.
Situation: A bicycle rides a slope, the bike moves down easily going faster and faster because of the heavy burden upfront and on the back. The packaging is not only heavy but also unstable, wide or high.
Problem definition
How can you cut down the speed of a fast riding bicycle, with means that are available to a market salesman in a village in Peru?
The solution has to be resistant to quite some power, extreme weather influences, should need little maintenance and is acceptable for the target group.
Program of Claims
the brake must be strong: able to withstand a short time force of 1000N in operating direction
the brake must be sturdy and keep its form: withstand a blow of 100N in any direction
the brake must be weather resistant, operate at heavy rain, work at least 1/4th of a year without maintenance
the brake must be simple enough, so that any local village workshop can build it in 4 hours.
the brake can only use a maximum of $1, - in material costs
Synthesis
Available materials:
wood (sticks and laths), rubber bands (car inner tires), car tires, a few nails, reed, cane, tin-plate, iron wire, hemp rope, scaffolding pipes, PVC-tubes, waste plastic, etcetera.
Sources of inspiretion
A rickshaw in Thailand used a brake of which was mounted on the rear fork and activated with the heel of the foot, while holding the leg in the proper position to be able to do so. This way of braking looked compact and reliable. A piece of rubber from a car tire was used as braking cushion.
Next steps:
contact with the target group: is the problem definition just?
search for comparable solutions in books and on internet
Detailing
Load rack for bicycles, to be made on the spot: Requirements for the design of a brake for a bicycle
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