You’ve probably wondered why some aircraft and motorcycles have slick tyres. They probably don’t need them, but fast motorcycles and street bikes do. This is due to the fact that their tyres contain inner tubes. These prevent sudden air leaks during launch and deformation of the tyres. In a previous article, we looked at the reasons for the slickness of the tyres in aeroplanes and motorcycles.
Aircraft with slick tyres
Smooth tyres improve aerodynamics. They reduce aerodynamic drag, improve separation of airflow, and reduce the amount of weight on the front tyre. The shape of aeroplanes and fast motorcycles also reshapes the vehicle’s footprint, rearranging aerodynamics to reduce weight. Aeroplanes, on the other hand, have a point symmetrical tire, which generates more vortices on the leeward side. Fast motorcycles and aeroplanes may soon be replacing their front tyres with these reshaped footprints.
In a wind tunnel, the researchers compared three types of tyres. They found that different patterns produce different pressure coefficients. This resulted in decreased air pressure along the direction of flow. Numerical simulations were used to examine the effect of each tread pattern on the flow field around the tires and its efficiency. For the first time, this study provides answers to the question “Why do aeroplanes and fast motorcycles have smooth tyres?”
In addition to the slick appearance, the slick tread on fast motorcycles and aeroplanes reduces the chances of overheating and blistering. Slick tyres also tend to wear out faster than their counterparts made from harder rubber. However, some auto sports drivers even wear out multiple sets of tyres in one day.
To determine the exact wear rate of tyres, Hillenbrand and colleagues used the UNECE guidelines. These recommended a wear rate of 700 mg per kilometre for a single tyre. Using this assumption, WDK assumes that electric cars are heavier than internal combustion engines, and therefore they will produce more wear on the tyres.
Street bikes with slick tyres
The slick tyre has a few advantages over the standard tread-on-tyre configuration. For example, a slick tyre resists punctures better than a tread-on-tyre configuration. Because the rubber on slicks is uniformly thick across its contact area, it resists penetrations better. In contrast, tread-on-tyre designs have uneven thicknesses and are less effective at preventing punctures.
To combat this problem, manufacturers began reducing the tread area on motorcycles. These bikes tended to have a smooth rear tire and a treaded front tire. This created vibrations in the back wheel, known as “chattering.” To solve this problem, manufacturers began incorporating rubber treads onto the front wheel. This new design made the bike’s front tire more grip-friendly, but also increased the size of the contact area.
Compared to street-based motorcycles, aeroplane tyres have smoother treads than motorbikes. The slicker tyres on fast motorcycles and aeroplanes enable them to achieve incredible speeds. These tyres can carry more weight and provide incredible grip levels, while improving stopping distance and fuel economy.
Speed wobbles are most common on motorcycles. At high speeds, aerodynamic drag forces shift the load to the rear tyre, un-weighting the front tyre. In the meantime, the contact patch of the front tyre swings outward and backward to restore its original position. The resulting shimmy vibrations are amplified by steering overshoot. Ex-F1 commentator Murray Walker explains the effect of weight and aerodynamics on motorcycle speed wobbles.
Smooth tyres save energy and reduce heat by reducing the flexing of tyre blocks. In fact, smooth tyres also increase the pressure distribution of the air in the front and reduce the amount of friction in the rear tyres. And smooth tyres also improve stability. You may also want to use warmers when riding, which can help increase the temperature of the tyre and decrease heat cycles.
Smooth tyres allow smooth riders to feel the traction levels more accurately, resulting in a higher rate of control. In addition, they have a more stable grip on the ground than riders on the street. Riding in the dirt is one of the best ways to gain experience and develop good bike handling skills. Aside from training in a dirt environment, riding in a mud pit is also an excellent way to condition your mind for smoother handling and a less dangerous situation.
Various myths are circulating about tyres. The most common is that a larger contact patch area leads to more grip. However, this is not necessarily the case. In fact, the coefficient of friction is directly related to weight. If the force on a tyre is too low, it will slide away. For this reason, aeroplanes and motorcycles have smooth tyres.
Cars with slick tyres
Slick tyres are used in motor racing and other fast cars. They are made without tread and offer incredibly high grip levels. By removing the tread, a car has more rubber on the road, which means that the Coefficient of Friction (COF) of the rubber will be reduced, which improves cornering grip. They also have a lower rolling resistance, are quieter, and reduce wear.
The primary use for slick tyres is in auto racing. The increased contact area between the road and the tyre allows the racer to accelerate and maintain traction on wet or dry surfaces. However, if the surface of a road is wet or slippery, a slick tyre’s traction is reduced. This means that slick tyres are not suitable for common road vehicles.
Completely slick tyres are illegal on most public roads, as they are incapable of handling wet pavement. A type of slick tyre commonly used in drag racing is called a cheater slick. It’s a slick type tyre, but has minimum tread grooves to meet legal requirements.
Slick tyres are not the only type of tyres used for high-performance racing. In the past, only motorcycles and aeroplanes used slick tyres, but slick tyres are now widely used on cars and other fast vehicles. DOT-approved street tyres are not only required for fast motorcycles and cars, but they also offer a higher safety and traction rating.
Bicycles and automobiles have slick tyres. Bicycle tyres were originally slick, but manufacturers eventually began adding light tread to differentiate between makes and models, and to improve the aesthetics of their bikes. Nowadays, bike tyres are also made with light tread, making them a better choice for off-road adventures.
The F1 tyre is the ultimate expression of modern tyre engineering. While a normal road tyre is designed to handle a force of about 1G, F1 cars have tyres with four times that force. The F1 tyres are wider and have no tread or grooves on the outside. Because of this, they offer more contact with the track, and improve acceleration.