Continental has more than 100 years experience in the development and production of bicycle tyres. So let us be your guide to important concepts in modern tyre technology, like tyre pressure, types, aquaplaning, and tyre construction methods. Soon, you’ll be a master the fundamentals. Just like us!
Not all tyres are created equal; whether it's a car or a bicycle, there are many types of tyre for different categories of vehicle.
Race bike tyres are designed for the tarmac. As such they're thin and light, with minimal tread for drag. Mountain bike tyres can tackle rocky, uneven terrain, and have more aggressive tread patterns for bumpy surfaces. Cyclocross bike tyres are designed for riding on tarmac, sand, dirt, mud, and sometimes even steps. And for a more relaxed pace, city and trekking bike tyres have a simple tread pattern for tarmac and the occasional gravel path.
In the automotive world, manufacturers design tyres for cars, SUVs and vans with different properties. Van tyres, for example, generally need to be more hard-wearing and able to support heavier loads than the average car tyre. SUV and 4x4 tyres, meanwhile, have special requirements like all-terrain and four-wheel drive.
Aquaplaning is a phenomenon that occurs when a layer of water builds up between the tyres of a car and the surface of the road. The tyres cannot grip the road properly, and the lack of traction means the driver loses control and is unable to steer, brake or accelerate.
Aquaplaning is most likely to happen when heavy rainfall builds up on the road surface. But the issue can be made worse by the condition of the car's tyres and the speed that it's travelling. For these reasons, it's important to:
Bicycles are not susceptible to aquaplaning. Whereas car tyres create a square road contact -- and have a straight leading edge with the road that makes it easier for a car to trap water under the tyre as it rolls -- bike tyres have a rounded contact with the road which pushes the water to either side of the tyre more efficiently. That's because they're designed to lean into corners.
Another key difference is that bike tyres are narrow and inflated to a relatively high air pressure. This means less water is in contact the leading edge of the tyre, and the high tyre pressure is more efficient at pushing water out from under the tyre. By comparison, car tyres are wide and inflated to a lower air pressure; this can make it difficult for water to escape from the middle of the car tyre.
Finally, there is the question of speed. A car travels much faster. Depending on the depth of water, this speed leaves less time for water to be dispersed. It's highly unlikely that a bicycle will ever travel fast enough to begin aquaplaning, no matter how furiously you pedal.
Today, the vast majority of car tyres are made using radial construction. By comparison, bicycles still use bias-ply tyres. What's the difference?
A radial tyre construction allows the sidewall and the tread to function as two independent features of the tyre. They're lighter and offer better fuel economy, due to reduced rolling resistance, but they also have a more flexible sidewall.
A bias-ply tyre is made from multiple rubber plies overlapping each other, where the crown and sidewalls are interdependent. These overlapped plies form a thick layer that is less flexible. Combined with inner tubes, the sidewall stiffness in bias-ply tyres is crucial for snakebite puncture resistance and overall performance.
The optimal tyre pressure depends on the size of the tyre and the weight it has to carry. The pressure in a tyre is measured in pounds per square inch, or PSI. Correct tyre pressure is important for proper road grip and energy efficiency. Always follow the manufacturer's guidelines to determine the correct air pressure.
Temperature has a significant effect on tyre pressure. An increase in temperature causes air in tyres to expand, which can lead to excess pressure if they are fully inflated to begin with. Cold temperatures will cause the air inside the tyres to contract, so that tyres which were correctly inflated previously have reduced tyre pressure when used in cold weather.
Changes in altitude have an effect on the tyre pressure because the external air pressure has changed. The level of pressure in a tyre is created from the relationship between the air inside the tyre and the air outside. The air offers less resistance if climbing to a higher altitude, which will create a larger amount of pressure within the tyre.