In recent times, cycling has evolved from a rather niche form of exercise and transportation into a global phenomenon helped, at least in part, by the exploits of British athletes at recent Olympics. More and more people across the globe are realizing the environmental and health benefits of cycling to work, or simply for enjoyment and exercise.
Baron Karl von Drais invented the first bicycle, also known as the dandy horse, in 1817 and this is widely considered to be the forerunner of the modern bicycle. Since this time, there have been many improvements from the initial design, incorporating new materials and computer-aided design. These changes have enabled a large number of specialized designs for different types of cycling.
Furthermore, bicycle innovations have tremendously benefited society, and many components from bikes have helped to develop the automobile, including pneumatic tyres, the tension-spoked wheel, the chain-driven sprocket and ball bearings.
Bicycle innovation continues to this day and has accelerated in recent times due to the increased interest in cycling. One of the main concerns regarding cycling is the safety of the rider at high speed, as there is little protection provided by the main frame of the bike. Therefore much work has been put into developing cycling helmets, which are designed to protect to head of the rider in the event of a crash. Though perhaps counterintuitive, recent developments in cycling helmets have utilized cardboard as the main protective material, often with stunning results. In this article AZoM looks at the way cardboard could shape the future of cycling, and what the potential drawbacks of this could be.
Materials Used in Conventional Cycling Equipment
Conventional cycling equipment is normally made of the materials listed below:
The first bicycles were made of wood. Hickory or bamboo was also used, as these woods have a long grains meaning stress can be handled better than with shorter grains or softer wood. The wooden bikes were reinforced at the joints with primitive steel.
As steel began to be produced in bulk, it was commonly incorporated into bicycles. Kid’s bikes and those needed for economical transportation still comprise rolled steel tubes. As steel is so economical and readily available, it is difficult to find a substitute especially where weight is not highly critical. Rolled steel tubing enables high stiffness and light weight when compared to steel.
For high-performance bikes, there is a need for high strength to weight ratios and cost is not a very significant factor. The first major breakthrough is cromoly, which is a manganese molybdenum or chromium molybdenum steel alloy. The alloy has higher strength than steel, and much lighter bikes can be constructed with this.
Aluminium & Its Alloys
It is believed that aluminium will outperform steel, especially due to its age hardening capabilities. High-strength aluminium frames can be built with thin-walled large diameter tubing. Though more material must be used to attain a strength comparable to steel, the result is still a light weight bike.
Carbon fibre frames can be made from a single piece, meaning joining the pieces is not a significant consideration in frame design.
The most important part of a cycling helmet or protect is the inner lining, which absorbs the majority of the impact. These linings are usually constructed from polymer foams, and in high-end helmets this is often EPS, or Expanded Polystyrene. Reinforcement can further be provided by nylon, polypropylene or metals.
Benefits and Drawbacks of Cardboard Bikes and Helmets
Anirudha Surabhi from the Royal College of Art in London was inspired to design the first cardboard helmet after suffering a bike crash and being hospitalized for several days.The new helmet, named Kranium, began gaining popularity in 2010. According to Surabhi, the cardboard helmet absorbs more impact when compared to a regular helmet. The laser-cut cardboard is used, instead of conventional expanded polystyrene (EPS) foam, in the Kranium, which is also lighter by 15%. The designer took inspiration from the ability of the woodpecker’s cartilage to withstand heavy impact repeatedly and designed the unique corrugated board. The honeycomb cardboard structure of Kranium is known as dual density honey comb board or D2.
SolidWorks was used for the distribution of load among the cardboard rib lateral angles. This renders the helmet more flexible than EPS and it can withstand multiple impacts, whereas a foam helmet would crack. The helmet is also provided with a water-repellent coating film to render it sweat and rain-proof. Another advantage of cardboard bikes and helmets is that they can be recycled, while EPS cannot be recycled.
Gafni, an Israeli inventor and an ardent lover of bicycles, took things a step further and ventured into the idea of designing an entire bicycle from cardboard. Gafni experimented with several cardboard materials to determine what produced the desired durability and strength. With the help of Origami techniques, Gafni designed the bike to be able to handle riders up to 485 pounds. These bicycles are highly economical as well as durable, fireproof, and waterproof.
The main drawback here is whether the idea of driving a cardboard cycle or wearing a cardboard helmet will actually be accepted by the general public. A change in perception is needed before cardboard based equipment can become commercially viable, as cardboard is not seen as a traditionally 'tough' material.
Environmental Benefits of Cardboard Cycling
Cardboard cycling is a totally new concept and one that further adds to the green credentials of cycling. Unlike EPS, cardboard is completely recyclable. Though some parts, such as pedals and wheels, are not made entirely of cardboard, they are still made of recycled material, making a cardboard bike almost certainly the cleanest way of traveling long distances.