Bike Frames

The bicycle is over 200 years old. It’s evolution proceeded quickly when it was first invented, and the changes continue to this day.

The bicycle can trace its history back to Germany in the year 1817, when inventor Karl Drais developed a push bike – one without pedals.

Like any other invention there were actually quite a few contributors to the changing design over the years. Other inventors who contributed to the evolution of the bicycle are Scottish blacksmith Kirkpatrick MacMillan, Frenchmen Ernest Michaux and Pierre Lallement, and Englishman James Starley – whose bicycle design, with the extremely large front wheel and the extremely tiny rear wheel was called the “penny farthing.” The “safety bicycle”, with both wheels the same height in a “diamond frame” that is still in use today, came into use in 1885, and in 1888 rides became much more comfortable with the invention of the “pneumatic” tire by Scotsman John Boyd Dunlop.

Over One Hundred Years Later, Improvement Continues

Just over a hundred years later, the basic design of the bicycle has not changed, but improvements are nevertheless being made all the time. The “new age” materials now in use – aluminum, titanium and carbon fire – have enabled bicycles to be made just as sturdy as can be desired, but with the light weight which most people these days desire.

The diamond bicycle frame consists of a series of tubes: the main triangle which consists of the head tube, top tube, down tube and seat tube. The rear triangle consists of the seat tube, paired chain stays and seat stays.

What are bicycle frames made of? The metal they’re made of is important, because a lot of factors have to be taken into account: the density of the metal will determine how heavy the bike is, the stiffness will affect the ride comfort and the control efficiency. There is always the danger of crashes so yield strength is important – how much force will permanently “deform” the metal? Also a consideration for crash-worthiness is the elongation capability of the metal. And then there’s the fatigue limit and the endurance limit.

A great many bike frames are made from steel. It’s got all the best qualities needed for a frame, but its major drawback is that it is very heavy.

Aluminum is very popular for use in bike frames, because of its very low weight. But the problem with aluminum is that it is very easy to bend it – and thus break it.

Titanium is rapidly becoming a popular material for bike frames. It’s strong, and its light…and its very expensive. Only high-end bicycles are made with titanium.

Carbon fiber is a non-metallic material for making bicycle frames. It is light weight, resists corrosion, and can be formed into practically any shape desired. However, carbon fiber does have low impact resistance, so it’s not so good for the mountain biker. And of course it’s expensive also

Bicycle manufacturers are always experimenting with new materials, of course. Currently, the use of thermoplastics is being tested, as is that of magnesium.

There’s great days ahead for the evolution of bicycling, so keep your helmet on and go full speed ahead!