The contact patch of most tires is about the size of your hand and has to handle a lot more weight and force than those big reeboks do. In addition, the shape of the contact patch will influence the performance of the tire and the vehicle its mounted on. Speedo reading tire 1 is assumed accurate tire susp. This part covers the dynamics of a tires contact patch.
Tire contact patch shape length vs width post wed aug 01, 2012 10. Physical understanding of transient generation of tire. Gathering data on a tires contact patch and monitoring its shape rolling at higher speeds has historically been difficult, costly, and has required highly specialized equipment. Also, it was determined and analyzed the influence of radial load and the air pressure against the surface of the contact patch. The contact patch static footprint shape will change, with a wider tyre, the contact patch will be wider, but also exactly. If the tire pressure is held constant, the width of the tire can only change the shape of the contact patch. What will change with the fitting of a wider tyre is the shape of the contact patch it will get wider, but shorter longways.
The contact patch is the only connection between the road and the vehicle. An effective rectangular contact area may be defined with an area equal to that of the envelope of the actual print. C2 is tire width, e2 pressure, g2 weight on the tire and b4 is circumference. Tire contact patch characterization through finite. Truck tire types and road contact pressures by pedro yap. The tire contact patch all vehicles are supported by a cushion of air contained in four flexible rubber tires. The second of the two tire factors affecting contact pressure is tire design. How to increase tire traction by controlling the contact patch of the tire based on size, rubber. The performance of a tire is significantly influenced by the shape of a tires contact patch and is dependent on its profile or what we call, aspect ratio. It is commonly used in the discussion of pneumatic i. Hard to believe, but shaq puts more rubber down than most cars do. If you could place a car on a glass floor and look at it from below, you would see four patches of rubber, most folks are surprised at the size of these four patches, depending on the vehicle each patch is a little smaller than a hand. The force from the weight on the tire must be equaled by the tire in terms of pressure x area. With respect to tire shape, the area of interest is the crown region and the dimensions of tread width and tread radius, figure 15.
Analysis of vehicle static steering torque based on tireroad. In order for the tyre contact area to lie flat on the road surface, the surrounding. Smithers has the tools and expertise to help engineers understand and optimize the tire contact patch. Tire contact patch lowering pressure gain traction. The process of varying the size of tread blocks around the circumference of a tire to minimize the noise generated by the tire as it rolls. Buy online for free next day delivery or same day pickup at a store near you. The tire contact patch, or tire footprint, is the area of the tire that directly connects the vehicle with the driving surface. Low inflation pressures tended to cause the wheel load to be distributed more heavily to the contact patchs central area for the radial tire and more heavily to the sidewall contact area for the bias tire. It is most commonly used in the discussion of pneumatic tires, i. Learn more about yokohama advan neova ad07 tires in pasorobles, ca from anthonys tire store. Rounded block design allows for a more stable contact patch that hugs the road. The shape appears to change from an oval shape at very low normal loads to a more rectangular shape at higher values of the load. All of a tires cornering, braking, and driving forces are generated within the tires contact patch.
The contact patch will vary in shape and size depending on the geometry of the tire, and this affects various performance characteristics of the tire. The optimized contact patch shape, provided by maxtouch construction, helps deliver extremely long tire life under the toughest conditions. Additionally, the calculated contact patch pressure rises from 6. The air pressure in your tires changes the shape of the contact patch, which directly impacts handling and performance. In the cases where the tire is overloaded or underinflated, the vertical contact stresses maximize towards the edges of the tire contact patch typical m shape, while lower loads and overinflated conditions result in maximum vertical stresses towards the center portion of the tire contact patch typical n shape. Contact patch is the portion of a vehicles tire that is in actual contact with the road surface. Given this alone, the contact patch area should be constant for a given tire pressure and load. Putting wider tires on a car is often referred to as putting more rubber on the road. When you install wider tires without changing anything else, the size of the tires contact patch i. Highway allseason passenger light trucksuv tire also suitable for commercial. Contact patches for the four radial tyres of a mediumsized family. Prints of the contact patch may be obtained by using ink or carbon paper. The size and shape of the contact patch, as well as the pressure distribution within the contact.
Calspan has developed a method which allows for the capture. Town fair tire tire contact patch also known as tire. A single contact patch between the wheel and the rail is typically the size of a. A wider tire will have a shorter, wider contact patch on the road than will a narrower tire at the same pressure, because the surface area of the contact patch must be the same to support the same. Once done you have a picture of the tire contact patch, and can easily measure the size of the patch in square inches width of. The first part of this paper presents the results of experimental estimation of the contact patch area depending on the normal wheel load and inflation pressure for different car tires. Why proper tire pressure matters news car and driver. Getting more out of your competition tires discount tire. Explanations for the input and output values can be found on the tire data information page.
Yokohama advan neova ad07 tires anthonys tire store in. Tire, finite element modeling, footprint phenomena, contact patch. With a soft sided tire, like a drag slick for example, the width of contact patch varies widely based upon air pressure and load. Tires with a higher profile or aspect ratio that is, the height of the sidewall is fairly large compared to the width of the tire, tend to have a long and narrow contact patch. This puts more wear on the tires shoulders, those rounded parts of the tire between. A larger contact patch more grip okay, most people will come to the conclusion that if you have more rubber on the road you will have increased grip. Maxtouch construction, a unique contact patch shape and design michelin comfort control technology uses computeroptimized design and precision manufacturing to offer greatly reduced vibrations and road noise. These include ink measurements of footprint shape and groovevoid ratio, optical contact pressure measurement, and multiaxis measurements of footprint stress, motion, and frictional energy. Analysis of tire contact parameters using visual processing. Maxtouch construction features a unique contact patch shape. Wider tires and contact patch shape putting wider tires on a car is often referred to as putting more rubber on the road.
This uniform groundcontact pressure greatly enhances dry road grip. Truck tirepavement contact pressure distribution characteristics for super single 18. Surprisingly, the contact patch of most tires is about the size of your hand. The design of the contact patch is an engineering feat that is specific not only to each manufacturer, but for each individual tire. Analysis of vehicle static steering torque based on tire. While the actual contact patch cant be seen by simply glancing at a vehicle, it is easy to see its location by viewing the profile, or outside of the wheel.
While the pneumatic pressurized tires used on autos today maintain a circular shape before they are mounted onto a wheel and vehicle, they change shape. We are an authorized michelin retailer with the best selection and pricing around. Using acceleration measurement on the tire inner liner, it was observed that the contact patch shape of the rolling tire changes nonlinearly with slip angle and becomes asymmetric. Just like you, your car also has a footprint but its called a contact patch. The contact patch will vary based on tire design, construction materials, the type of tire, tread and shoulder design and sidewall construction. Its the portion of your vehicles tire tread that makes contact with the road surface. We address the belief that wider tyres are always better, that wider tyres are faster because of contact patch shape. Tire contact patch shape length vs width post wed aug 01, 2012 4. Apart from tire force and torque measurements, two further issues were investigated experimentally.
Instead of increasing patch size you simply change its shape. A system that maximizes the contact patch area during cornering through a combination of asymmetrical tread patterns and underlying belts. From 390 lb to 773lb almost double the tire load the contact patch size only increases by 25%, even assuming laterally constrained sidewalls. The paper should be outline paper divided into oneinch blocks, it makes measuring the contact patch easier. The shape of a tires contact patch or footprint greatly influences its performance and is dependent on its profile or aspect ratio. Town fair tire tire contact patch also known as tire footprint. Highway allseason passenger light trucksuv tire also suitable for commercial light truckvan applications. Studies have found that the contact patch has a circular shape at higher tyre inflation pressures. Jan 25, 2014 the paper should be outline paper divided into oneinch blocks, it makes measuring the contact patch easier. Air pressure always plays an important role in tire performance, and especially for track days its even more critical. For the sake of technicality, the contact patch given the same tire pressures must retain the same area, albeit in a different wider shape. In the past, wheels were usually manufactured by shrink fitting a tyre onto a hub. Truck tire pavement contact pressure distribution july 1989.
Jun 15, 2017 whats more, the tires contact patchwhere the rubber meets the roadwill not be its correct shape. The contact patch shape for a tire traveling at 38 mph 60 kmh comparing when the tire is rolling straight ahead sa 0 deg versus when cornering sa 5 deg. Unique casing shape improves feel and driveability by optimizing the. This approach uses the tire test bench with the set of contact patch monitoring based on image processing procedures. Helps reduce unneccesary friction when the tire rolls. Tire contact patch lowering pressure gain traction engine basics. The size and shape of the contact patch, as well as the pressure distribution within the. G11 and i11 show length and width of the patch and j12 and k12 the area of the contact patch. Tire contact patch shape does and that can be influenced by the differences in tire design of different size wheels. Anthonys tire store in pasorobles, ca has the best yokohama advan neova ad07 tires you can ask for for your vehicle. Jun 08, 2019 we address the belief that wider tyres are always better, that wider tyres are faster because of contact patch shape.
This is part 6 of my 10 part series on how race car tirestyres work. For high performance driving, the tires contact patch would. Truck tire types and road contact pressures by pedro yap the. Some people may believe that a wide tire will give you a bigger contact patch, but this is not usually the case either, as you are putting a wider tire on the same width. Evaluation of tiresurfacingbase contact stresses and. The size and shape of the contact patch, as well as the pressure distribution within the contact patch, are important to the ride qualities and handling characteristics of a vehicle. Whats more, the tires contact patchwhere the rubber meets the roadwill not be its correct shape. Evenly distributes the forces of acceleration, braking, and cornering. Nov 17, 2001 what will change with the fitting of a wider tyre is the shape of the contact patch it will get wider, but shorter longways. Once done you have a picture of the tire contact patch, and can easily measure the size of the patch in square inches width of the patch times the height of the patch.
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