Rain tyre

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Lewis Hamilton competes through the rain at the 2016 Monaco Grand Prix. The treads of his wet tyres are visible. Hamilton - 2016 Monaco GP 02.jpg
Lewis Hamilton competes through the rain at the 2016 Monaco Grand Prix. The treads of his wet tyres are visible.

A rain tyre or wet tyre (spelt tire in American English, commonly shortened to wet) is a special tyre used in motorsport in wet weather as opposed to a slick tyre used in dry conditions. It is very similar in many ways to the tyres found on normal road cars. [1]

Contents

Rain tyres are not used in NASCAR, ARCA and INDYCAR sanctioned races held on oval tracks as these races are invariably halted when the track is wet due to safety concerns regarding the large amounts of spray involved reducing visibility, as well as a lack of traction in banked corners at high speeds.

Structure

Rain tyres have a specially designed structure making them better adapted for their application than any other tyres. However, not all rain tyres obey the same design principles. Certain factors need to be taken into account when designing a good rain tyre, such as the:

Grooves

Detailed view of rain tyres equipped by Lewis Hamilton at the 2016 Monaco Grand Prix Hamilton - 2016 Monaco GP 04.jpg
Detailed view of rain tyres equipped by Lewis Hamilton at the 2016 Monaco Grand Prix

Rain tyres are cut or moulded with patterned grooves or tread in them. This allows the tyre to quickly displace the water between the ground and the rubber on the tyre. If this water is not displaced, the car will experience an effect known as hydroplaning as the rubber will not be in contact with the ground. These grooves do not help the car grip contrary to popular belief, however if these grooves are too shallow, the grip will be impaired in wet conditions as the rubber will not be able to make good contact with the ground. The patterns are designed to displace water as quickly as possible to the edges of the tyre or into specially cut channels in the centre of the tyre. Not all groove patterns are the same. Optimal patterns depend on the car and the conditions. The grooves are also designed to generate heat when lateral forces are applied to the tyre.

Rubber

Rain tyres are also made from softer rubber compounds to help the car grip in the slippery conditions and to build up heat in the tyre. These tyres are so soft that running them on a dry track would cause them to deteriorate within minutes. Softer rubber means that the rubber contains more oils and other chemicals which cause a racing tyre to become sticky when it is hot. The softer a tyre, the stickier it becomes, and conversely with hard tyres.

When rain has stopped falling, and a track is in the process of drying, it is not unusual to see drivers intentionally driving through wet puddles and damp portions of the course, in order to cool the rubber and stave off tyre deterioration. As soon as possible, drivers will revert to slick tyres to maintain competitive speeds.

Shape

Currently, F1 rain tyres have a larger diameter than dry tyres, with the wets having a diameter of 10mm more than the slicks. [2] This increases the ride height of the car and makes it less vulnerable to aquaplaning.

Sometimes[ when? ] rain tyres are designed to have a smaller diameter than their dry counterparts. This means that the wheel spins faster and more water is thrown off the tyre by overcoming centripetal force. Some rain tyres[ example needed ] are also narrower than the dry counterparts. This smaller "footprint" reduces the chances of hydroplaning.[ citation needed ]

Intermediate tyres

Intermediate tyre by Pirelli at the 2016 Austrian Grand Prix Intermediate tyres Austrian GP 2016.jpg
Intermediate tyre by Pirelli at the 2016 Austrian Grand Prix

Some racing series such as Formula One allow an intermediate (inter) tyre. This tyre is designed to be used in conditions too wet for slick tyres and too dry for wet tyres. They are made with rubber compounds slightly softer than slick tyres and are cut with grooves like the rain tyre but shallower to prevent excessive heat build up. Former Formula One tyre supplier Bridgestone referred to the "intermediate" tyre as the "wet" tyre, and to what are known as "full wets" as "monsoon tyres".

Invention

The original invention of the rain tyre is attributed to Uniroyal, in 1969. [3] [4] They were the first to understand the water-deflecting properties of directional V-shaped tread and the first to use biomimicry with the development of “Shark Skin Technology [5] ”, which helps to prevent aquaplaning.

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<span class="mw-page-title-main">Pirelli</span> Italian multinational tyre manufacturer

Pirelli & C. S.p.A. is an Italian multinational tyre manufacturer based in the city of Milan, Italy. The company, which has been listed on the Borsa Italiana since 1922, is the 6th-largest tyre manufacturer and is focused on the consumer production of tyres for cars, motorcycles and bicycles. It is present in Europe, the Asia-Pacific, Latin America, North America and the Post-Soviet states, operating commercially in over 160 countries. It has 19 manufacturing sites in 13 countries and a network of around 14,600 distributors and retailers. In 2015, China National Chemical Corp. Ltd. (ChemChina) took controlling interest of Pirelli; with the Chinese state-owned company agreeing to maintain the tyre company's ownership structure until 2023.

<span class="mw-page-title-main">Tire</span> Ring-shaped covering that fits around a wheels rim

A tire or tyre is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which the wheel travels. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, providing a flexible cushion that absorbs shock as the tire rolls over rough features on the surface. Tires provide a footprint, called a contact patch, designed to match the vehicle's weight and the bearing on the surface that it rolls over by exerting a pressure that will avoid deforming the surface.

<span class="mw-page-title-main">Racing slick</span> Type of tire used in auto racing

A racing slick or slick tyre is a type of tyre that has a smooth tread used mostly in auto racing. The first production slick tyre was developed by M&H Tires in the early 1950s for use in drag racing. By eliminating any grooves cut into the tread, such tyres provide the largest possible contact patch to the road, and maximize dry traction for any given tyre dimension; see Performance. Slick tyres are used on race tracks and in road racing, where acceleration, steering and braking require maximum traction from each wheel. Slick tyres are typically used on only the driven (powered) wheels in drag racing, where the only concern is maximum traction to put power to the ground, and are not used in rallying.

<span class="mw-page-title-main">Aquaplaning</span> Loss of traction due to water buildup under tires

Aquaplaning or hydroplaning by the tires of a road vehicle, aircraft or other wheeled vehicle occurs when a layer of water builds between the wheels of the vehicle and the road surface, leading to a loss of traction that prevents the vehicle from responding to control inputs. If it occurs to all wheels simultaneously, the vehicle becomes, in effect, an uncontrolled sled. Aquaplaning is a different phenomenon from when water on the surface of the roadway merely acts as a lubricant. Traction is diminished on wet pavement even when aquaplaning is not occurring.

<span class="mw-page-title-main">Tire tread</span> Rubber on the circumference of a tire that contacts the ground

The tread of a tire or track refers to the rubber on its circumference that makes contact with the road or the ground. As tires are used, the tread is worn off, limiting its effectiveness in providing traction. A worn tire can often be retreaded.

<span class="mw-page-title-main">Siping (rubber)</span> Process to improve rubbers traction

Siping is a process of cutting thin slits across a rubber surface to improve traction in wet or icy conditions.

<span class="mw-page-title-main">Uniform Tire Quality Grading</span> Standards for passenger car tires

Uniform Tire Quality Grading, commonly abbreviated as UTQG, is a set of standards for passenger car tires that measures a tire's treadwear, temperature resistance and traction. The UTQG was created by the National Highway Traffic Safety Administration in 1978, a branch of the United States Department of Transportation (DOT). All passenger car tires manufactured for sale in the United States since March 31, 1979 are federally mandated to have the UTQG ratings on their sidewall as part of the DOT approval process, in which non-DOT approved tires are not legal for street use in the United States. Light truck tires are not required to have a UTQG. It is not to be confused with the tire code, a supplemental and global standard measuring tire dimensions, load-bearing ability and maximum speed, maintained by tire industry trade organizations and the International Organization for Standardization.

<span class="mw-page-title-main">Snow tire</span> Tires designed for use on snow and ice

Snow tires, also known as winter tires, are tires designed for use on snow and ice. Snow tires have a tread design with larger gaps than those on conventional tires, increasing traction on snow and ice. Such tires that have passed a specific winter traction performance test are entitled to display a 3PMSF symbol on their sidewalls. Tires designed for winter conditions are optimized to drive at temperatures below 7 °C (45 °F). Studded tires are a type of snow tires which have metal or ceramic studs that protrude from the tire to increase traction on hard-packed snow or ice. Studs abrade dry pavement, causing dust and creating wear in the wheel path. Regulations that require the use of snow tires or permit the use of studs vary by country in Asia and Europe, and by state or province in North America.

<span class="mw-page-title-main">Tire maintenance</span>

Inspection and maintenance of tires is about inspecting for wear and damage on tires so that adjustments or measures can be made to take better care of the tires so that they last longer, or to detect or predict if repairs or replacement of the tires becomes necessary. Tire maintenance for motor vehicles is based on several factors. The chief reason for tire replacement is friction from moving contact with road surfaces, causing the tread on the outer perimeter of tires to eventually wear away. When the tread depth becomes too shallow, like for example below 3.2 mm, the tire is worn out and should be replaced. The same rims can usually be used throughout the lifetime of the car. Other problems encountered in tire maintenance include:

<span class="mw-page-title-main">Formula One tyres</span> Tyres designed for Formula One cars

Formula One tyres play a significant role in the performance of a Formula One car. The tyres have undergone major changes throughout the history of Formula One with different manufacturers and specifications used in the sport.

<span class="mw-page-title-main">Bicycle tire</span> Tire that fits on the wheel of a bicycle

A bicycle tire is a tire that fits on the wheel of a bicycle or similar vehicle. These tires may also be used on tricycles, wheelchairs, and handcycles, frequently for racing. Bicycle tires provide an important source of suspension, generate the lateral forces necessary for balancing and turning, and generate the longitudinal forces necessary for propulsion and braking. Although the use of a pneumatic tire greatly reduces rolling resistance compared to the use of a rigid wheel or solid tire, the tires are still typically the second largest source, after wind resistance, of power consumption on a level road. The modern detachable pneumatic bicycle tire contributed to the popularity and eventual dominance of the safety bicycle.

<span class="mw-page-title-main">Motorcycle tyre</span> Tyres of a motorcycle

A motorcycle tyre is the outer part of motorcycle wheel, attached to the rim, providing traction, resisting wear, absorbing surface irregularities, and allowing the motorcycle to turn via countersteering. The two tyres' contact patches are the motorcycle's connection to the ground, and so are fundamental to the motorcycle's suspension behaviour, and critically affect safety, braking, fuel economy, noise, and rider comfort.

The following is a glossary of terminology used in motorsport, along with explanations of their meanings.

<span class="mw-page-title-main">Tyre label</span>

The Tyre Label is a mark for motor vehicle tyres. Manufacturers of tyres for cars, light and heavy trucks must specify fuel consumption, wet grip and noise classification of every tyre sold in EU market starting in November 2012.

<span class="mw-page-title-main">2011 British Grand Prix</span> Motor car race

The 2011 British Grand Prix was a Formula One motor race held on 10 July 2011 at the Silverstone Circuit in Northamptonshire and Buckinghamshire, England, and won by Fernando Alonso. It was the ninth race of the 2011 season, and saw the introduction of a ban on off-throttle blown diffusers, the practice of forcing the engine to continue to produce exhaust gasses to generate downforce when drivers are not using the throttle. The race also saw the Formula One debut of future Grand Prix winner Daniel Ricciardo.

<span class="mw-page-title-main">2011 Hungarian Grand Prix</span> Motor car race

The 2011 Hungarian Grand Prix was a Formula One motor race that was held on 31 July 2011 at the Hungaroring in Mogyoród, near Budapest, Hungary It was the eleventh round of the 2011 Formula One season, and the 27th running of the Hungarian Grand Prix, and the 26th time it had been held as a round of the World Championship. The 70-lap race was won by McLaren's Jenson Button, in his 200th Grand Prix start, after starting from third on the grid. Championship leader Sebastian Vettel, who started the race from pole position, finished in second place for Red Bull Racing, and Fernando Alonso completed the podium in third position for Ferrari.

<span class="mw-page-title-main">Outline of tires</span> Overview of and topical guide to tires

The following outline is provided as an overview of and topical guide to tires:

<span class="mw-page-title-main">Bar grip</span>

Bar grip tyres, or 'NDT' in US military parlance, are an early tyre tread pattern developed for off-road use.

<span class="mw-page-title-main">FIA Formula 2 Championship</span> Single-seater racing championship

The FIA Formula 2 Championship is a second-tier single-seater championship organized by the Fédération Internationale de l'Automobile (FIA). Held on racing circuits, the championship was introduced in 2017, following the rebranding of the long-term Formula One feeder series GP2. The series' original founders were Flavio Briatore and current managing director Bruno Michel.

<span class="mw-page-title-main">FIA Formula 3 Championship</span> Single-Seater Racing Championship

The FIA Formula 3 Championship is a third-tier international single-seater racing championship and organised by the Fédération Internationale de l'Automobile (FIA). The championship launched in 2019 as a feeder series for the FIA Formula 1 World Championship and FIA Formula 2 Championships. It was the result of a merger between two third-tier single-seater racing championships, the GP3 Series and the FIA Formula 3 European Championship as it was announced on 10 March 2018. The championship is part of the FIA Global Pathway consolidation project plan. Unlike its predecessor, the Formula 3 European Championship, the series runs exclusively in support of Formula One races.

References

  1. McFadyen, Peter (2008). Motor Racing at Oulton Park in the 1970s. Veloce Publishing Ltd. ISBN   978-1-84584-164-5.
  2. "F1 tires: details and technical data | Pirelli". www.pirelli.com. Retrieved 2021-12-02.
  3. "Our story". www.uniroyal-tyres.com. Retrieved 2023-11-21.
  4. "Uniroyal". Uniroyal Tyres. Retrieved 2023-11-21.
  5. "The advanced Shark Skin Technology for maximum aquaplaning safety | Uniroyal". www.uniroyal-tyres.com. Retrieved 2023-11-21.