WhyBicycles need to be compact foldable to: integrate with public transport, prevent theft by taking it inside, use it to and from parking lots as an extension of car transportation.
Bicycles should need less en cleaner to produce materials, should last longer and should be easier to repair.
Bicycles, as a simple product, in use world wide, should be produced in local workshops, hence with minimal investment.
Everywhere in the world more people live is cities that grow bigger. If roads and traffic allow the use of bicycles, transport by bicycle in the center of cities is by far the fastest, compared to public transport or by car. It allows most freedom of choice of (intermediate) destination. Precondition is that a bicycle can be stored inside and can be taken along in public transport as well as in a car.
To cope with the demands of urban development, bicycles need to be developed comparable to umbrella's, that are very easy, very compact almost automatically to fold and unfold. Or be comparable to camping chairs that weight only a few kilo's, but take the weight of two persons. And take rough handling such as modern suitcases during luggage handling on airports.
Present production of bicycles depends heavily on welding tubes together as method of construction. As welding introduces high local tensions on micro scale, potentially leading to fatigue-cracks, a wall thickness is used, larger than needed for functional loads. With other methods of construction, like thin sheet parts fastened with spot-welding, folding seems, stapling on to intermediate parts or click-assembly, welding can be avoided. Such methods are general used in all comparable products.
Bicycle repair and upkeep could be regarded as an extension of its manufacture. As repair and upkeep is done locally and small scale, the process of manufacture should be adjusted to that scale.
HowFunctionality of bicycles regarding weight, cost and compact folding has to come to the level of present umbrella's and foldable camping chairs.
Production could be done from pre-finished(painted) sheet metal, when welding is avoided. Light tooling, as thin sheet metal is easy to cut and shape.
Low investment and local manufacture allows fast introduction of innovative development. Open source info exchange will raise functionality quickly.
Radical re-design of the bicycle is essential to attain modern standards of functionality. Modern standards of functionality will add more value to less material, when traditional concepts are left of how a bicycle should be composed or should look and function. Only its value as a human propelled transporter count, when easier to work materials and cheaper methods of assembling are used.
Source of inspiration for design is the umbrella, folding back to a few percent of its unfolded volume. A camping chair is expected not to collapse, when someone sits in it on someone's else lap. But the weight of such a chair may be less then one kilo.
Comparison with modern plastic suitcases shows that shell-like shapes out of plastic offer the needed strength.
The design Demotech contributed to a design contest in Japan in 1973, shows to what such a radical re-design of all parts and the major part of its functionality can lead. Most of the above demand could have been fulfilled with it.
Pre-painted thin metal sheet can easily be folded into stiff tubular sleeves, that can be heavily loaded, as their use in cars prove. Industry offers many low-cost methods to combine such parts. However crafts, even manufacture at home can make good use of it as only simple tools are needed for it and no heat or paint is used. Some complicated shapes like a saddle of a bicycle can be made with rotational moulding, a technique applicable in a workshop, using recycled plastic and very low initial investment.
A new design for a bicycle should aim at a scale that production (or assembly) of the bicycle is economic when integrated with a shop for maintenance and repair. This design could also aim at production of some of the needed parts at the yard of local families, making good use of work capacity of people that otherwise could not economically participate. A franchise construction could take care of solving logistic problems that can not be solved small-scale.
Introduction to the Tin Bicycle
Introduction by Reinder van Tijen
Dieren Februari 12th 2002-02-12
In the early seventies, also the early days of Demotech, I took part in a Japanese design contest. It was about bicycles, any bicycle, anything bicycle-like for personal transport was welcome to be admitted.
A few years before I had quitted my job as a designer at a well-known Dutch bicycle factory. So I knew quiet well the ins and outs of bicycle manufacturing. But on behalf of this design contest, I formulated for myself different design criteria. Such as being applicable in an economic environment where capital would be extremely scarce and craftsmanship would be readily available. As purchasing power of potential buyers would be low, the production of the bicycle should be highly efficient. As the need for personal transport is high the product should match at least the existing expectations.
My entry, named the ‘Tin Bicycle’ was rewarded a third prize. For that reason it got some publicity and we got some support in the construction of a prototype of this design. We could demonstrate that ‘tin’, being 0,3 mm thick steel sheet metal, coated with tin or paint, was well suited for the job. A ‘tin’ bicycle frame was produced and tested under normally to be expected loads. It stood well up to it.
No further development followed, as all attention within Demotech had to be focussed at the development of the rope pump.
I hope for the chance to renew work on this design. There is a huge need for a bicycle that even surpassed the design criteria I choose for the ‘Tin Bicycle’. With all the experience I gathered in design for local manufacture, I have high hopes such criteria can be met.
Also see: The "Tin Bicycle", a sustainable way to produce bicycles
Links related to bicycle use and manufacturing
What other people say...
If you like you can add your own comment
by Hans Baarslag - Fri Oct 31 (2003)
I would call it breefcasebike To stress the smallness of the bike when
by Reinder / Demotech - Fri Oct 31 (2003)
Re: tin bicycle
> I would call it briefcase bike To stress the smallness of the bike when
> folded. Hans
First of all it should function as a good and sturdy bicycle. Second it is
made out of 'tin', thin easy to work metal sheet. So it can be made by
local workshops, no need for heavy presses, welding or soldering. OK, the
idea is also it can be very compactly folded. I thought at that time
(1973!) that the idea of using tin was the most amazing and should come
back in its nickname.
When I have a chance to work again on this design, I indeed would try to
make it foldable very compactly, even smaller than the measures of the Tin
Bicycle. Look (use Google) at the A-Bike of mr Sinclair. It should compete
with that kind of foldability!
by firstname.lastname@example.org - Sun Dec 05 (2004)
Hello there, cool site!
I am an engineering student at the University of Washington looking into
designing a fuel cell powered bicycle. I am having trouble finding safety
standards against car crashes and basically the design specifications
engineering the bike structure. Do you have any suggestions on where I
Thanks in advance,
If you like you can add your own comment
What name would YOU give to this device?
You can assist search machines to find this topic by sending Demotech an email form with one or more appropriate names for this device in your language. Such as: fiets, vouwfiets, klaprad, transportfiets, vouwbare fiets, bicyclette, ....