VALVES, RIMS, FLAPS AND MUDFLAPS
In 1845 Robert William Thomson and in 1888 John Boyd Dunlop, thought air can make bicycle riding comfortable. The tube was invented but it needed protection from the rough road condition. To protect it a cover or shield was prepared in many ways by different people. Ultimately it attained the present shape with a name ‘tire’, a short form for attire. Tire is also known as cover.
The development of various modes of transportation with tremendous load bearing capacity and with ability to move at a faster speed happened and still continuing. The support of this cover or tire is just taken for granted. I have read about development of such vehicles including the recent monster aircraft of Paul Allen. Nowhere I could find a word about tire which will be bearing the brunt. It is just taken for granted. Can we say that it is because of great faith in it?
If this is an appreciation we can censure or reprimand it also. Like we see in movies the most trusted aid replacing the master, tires that came to protect the tubes, now almost eliminated it in all types of tires.
It is said that the air is carrying the load and if tires can do it without it why have it.
For a tubeless tire need is a good well-fitting rim which will not allow air to escape and an additional thin but strong square woven rubberized fabric as an inner cover.
In developed countries roads are good and chances of sharp objects like nails puncturing them are remote, so tubeless tires became order of the day. But in developing and under developed countries roads are in pathetic and awful condition strewed with nails and sharp objects making repairing the punctured tires as a lucrative profession.
But such roadside repairing places have no sophisticated equipment. While removing the tire/tube the rims are damaged making it vulnerable for escape of air. So, in these countries still tubes are in use along with tires.
It is not a joking matter as the conditions of the rims are so bad it is advised to fill the air on tires keeping them in a well-protected steel cage or in a sturdy bag tied to a pillar.
Flaps are not used for tubeless tires and smaller tires. They are used with truck tires as an internal covering to the rim where tube will come into contact. Flaps are a rubber sleeve protects tubes from chafing effect from the rim. Besides that, when trucks run at a high speed with load, particularly in summer under hot weather condition for a long time tremendous heat develops. Rims and even tires will be very hot. Flaps as an insulator protects the tube.
Mud-flap or mud guard is used in vehicle fender to protect the vehicle, passengers, other vehicles, and pedestrians from mud and other flying debris thrown into the air by the rotating tire.
Now let us look into these components one by one.
Many companies are making valves now. In the initial stage the Dunlop Valve or English valve, Presta valve or French valve and Schrader valve or American valve were the known companies.
Whether one uses tube and tire or tubeless tire need a
valve for maintaining the air pressure. Dunlop made a valve when he came with his bicycle tires but it did not permit deflation. In 1891 Mr. C.H. Woods a cotton spinner, invented a perfect little valve which was adapted it. The Dunlop valve, (also called a Woods valve or an English valve) is a type of pneumatic valve stem in use in some countries, such as Japan, Czech Republic, India, Pakistan, Sri Lanka, Poland, Romania, Russia, the Netherlands, Germany, Britain, Norway, Finland, Sweden, Denmark, and a number of developing countries, mostly on bicycle inner tubes.
The Presta valve (also called Sclaverand valve or French valve) is a valve commonly found in high pressure road style and some mountain bicycle inner tubes. It comprises an outer valve stem and an inner valve body. A lock nut to secure the stem at the wheel rim and a valve cap may also be present. It was invented by a person named Sclavarand.
The outer valve stem is manufactured in various lengths for different applications, and has a narrower diameter (6 mm) than Dunlop and Schrader valves (8 mm). The weakest point of a bicycle rim is usually the hole for the valve stem. The smaller hole for a Presta valve makes it possible to have extremely narrow wheels while maintaining sufficient strength in the wheel.
The air pressure in an inflated tire holds the inner valve body shut. A small screw and captive nut on the top of the valve body permits the valve to be screwed shut and ensure that it remains tightly closed. The nut must be unscrewed to permit airflow in either direction. This must be done before attaching a pump. The screw remains captive on the valve body even when unscrewed fully; it is tightened again after the tire is inflated and the pump removed. The valve cap protects the valve body, keeps dirt and mud out of the mechanism, and also prevents the valve from damaging the tube when it is rolled for storage, but is not necessary to prevent pressure loss.
Because the rims of bicycles drilled for Presta valves cannot accommodate the wider Schrader valves, it is often the case that rims need to be drilled for such replacements which can structurally weaken the rim. Conversely, when a Presta valve is fitted into the larger Schrader rim hole, grommets or reducers are sometimes used to take up the extra space.
The standard Presta valve has an external thread. An adapter can be fitted onto this external thread to permit the Presta valve to be connected to a pump with a Schrader chuck. The same adapter, because of a coincidence of thread sizes, may be able to convert a Schrader pump into one that can connect to flexible adapters of either kind.
On many race wheels, they have such a high, thick, rim for aero-dynamics, that a standard Presta valve is too short. Valve extenders have been developed to adapt shorter valves to deeper, thicker, rims. There are two types depending on whether the Presta core is removable.
Tubeless systems: Unlike Schrader cores, the inner parts of the valve, the valve core, of standard Presta valves often cannot be removed from the stem. Since the core usually has to be removed to use a tubeless or Universal System Tubeless (UST) setup so that tire sealant may be added, removable core Presta valves, and removable stems, have become more common.
The Schrader valve (also called American valve) is a type of pneumatic tire valve used on virtually every motor vehicle in the world today. The Schrader company, for which it was named, was founded in 1844 by August Schrader. The original Schrader valve design was patented in the United States in 1893.
The Schrader valve consists of a valve stem into which a valve core is threaded, and is used on virtually all automobile tires and motorcycle tires and most
wider rimmed bicycle tires. The valve core is a poppet valve assisted by a spring.
A young mechanic named August Schrader, arrived in New York in 1840 from Hamburg Germany. In 1846 Schrader took interest in an underwater race and was convinced that he could improve the design, and manufacturing of the helmets.
Initially, Schrader developed supply fittings and valves for rubber products like air pillows and life preservers. But his inventive nature and strong interest in diving eventually led him to design and manufacture improved diving helmets and air pumps, catapulting the young company into more than 50 years of successes in the dive equipment business.
By 1890, having brought his son, George Schrader, into the business, the senior Schrader's attention turned to bicycles — specifically the newly popular pneumatic tires.
During this time, Schrader and his son developed what would become the company's most popular and famous invention — the Schrader pneumatic tire valve — the very same valve that is used on every motor vehicle in the world today. This pioneering work led to the patent of the tire valve cap and, soon after, tire valves for automobiles were introduced.
Since the breakthrough inventions of the 1800s, Schrader has continued a proven culture of innovation. Schrader pioneered tire pressure monitoring systems (TPMS), a safety feature now standard on all passenger vehicles in the United States that is being adopted globally via mandatory legislation. As the number-one supplier of TPMS sensors and valves worldwide, Schrader's TPMS systems, components and tools are used by many of the world's leading automobile manufacturers, and throughout the Aftermarket service and repair communities. In fact, over 54 percent of all global OEM vehicle platforms utilize Schrader direct TPMS technology, with over 300 million Schrader TPMS sensors in operation worldwide.
In addition to a legacy of performance with leading Original Equipment Manufacturers (OEMs] in the automotive sector, today Schrader delivers customer-driven innovation to a diverse range of industries and applications—from industrial production, to off-road/heavy-duty equipment, marine to agriculture, aerospace and oil and gas-delivering valve and sensing solutions that protect and perform.
August Schrader's pioneering spirit and appetite for invention has remained at the heart of Schrader's business for over 165 years. While the company's focus has expanded over the years, August Schrader's zeal for innovation and the production of high quality products continues to drive the company forward.
In the United States anyone driving a newer vehicle, is beneﬁtted from TPMS technology. In fact, if anyone driving a vehicle manufactured after 2000, it is very possible that he is driving a TPMS-enabled vehicle.
In Europe or Asia, one soon to have this life-saving technology as well. So, what is TPMS? And why is it important?
TPMS stands for Tire Pressure Monitoring System. TPMS is a warning system indicating to the operator when a tire is significantly under-inﬂated. Following a series of often fatal automobile crashes and a resulting nationwide tire recall, in 2000, the United States Congress passed the Transportation Recall Enhancement, Accountability and
Documentation (TREAD) Act. With driver safety its primary concern, the TREAD Act mandated, among other directives, that all new passenger cars, multi-purpose passenger vehicles, trucks and buses that weigh 10,000 pounds or less in the United States be equipped with a tire pressure monitoring system a warning system that alerts the driver
when a tire is significantly under-inﬂated. Following a phased implementation schedule, the U.S. market reached 100 percent compliance with the 2008 model year and now tire pressure monitoring systems are standard on all cars in the United States.
In the early 1990s, Schrader was developing the first-generation of sensing technology that measured pressure and temperature in automotive tires. By 1993, Schrader ﬁled for the first patent surrounding TPMS and on February 4-, 1997, Schrader inventor Jerry Robinson was granted Patent #5,600,301 as “Remote Tire Pressure Monitoring System Employing Coded Tire Identification and Radio Frequency Transmission, and Enabling Recalibration upon Tire Rotation or Replacement." The first production vehicles installed with Schrader TPMS technology occurred in 1997, with the Chevrolet@C5 Corvette and Prowler platforms. New bolt-on TPMS innovations followed such as the Schrader “snap-in" valve type for TPMS [Schrader inventor Frank Banzhof received US Patent #6,005,4-80 on December 21, 1999]. Building on the company's success, in 1999 Schrader equipped the RenauIt@ Laguna with 100 percent TPMS-fitment, resulting in the first high-volume production of a TPMS enabled vehicle. Additional automotive manufacturers followed; however, the next major milestone was the TREAD legislation that spurred TPMS adoption in the United States, beginning in the early 2000s.
As traditional TPMS evolves globally, Schrader has extended similar
technology to other adjacent markets and applications. For example,
Schrader has delivered tire pressure monitoring for the large heavy-duty
earth-moving segment where tires are a premium item and operational
downtime is avoided at all costs. Today Schrader delivers customer-
driven innovation to a diverse range of industries and applications — from industrial production, to off-road/heavy-duty equipment, marine to
agriculture, aerospace and oil and ~ ' " ' ' id sensing solutions that
protect and perform.
Nearly 15 million new vehicles enter the North American market every year — each required by law to include TPMS technology. In 2006, at the behest of Schrader, an independent research firm measured 14.5 million TPMS-equipped vehicles in operation in North America. That number grew to 4-2.7 million in 2008, 64-.6 million in 2010, and is projected to hit 146.8 million by 2016. TPMS is an increasingly important technology for consumers, whether they are familiar with the technology or not. Motorists can feel the effects of incorrect tire pressure both on the road and in the pocketbook. It affects how a car brakes and handles while driving. It makes a difference in how quickly tires wear out. Tires filled to the right pressure can make a car more fuel efﬁcient, saving money at the pump which is especially important with rising fuel costs. It lowers carbon emissions too, which lessens our environmental impact. TPMS automatically checks tire pressure and alerts drivers when the air is low — taking out the guesswork and saving time and money.
The continued proliferation of TPMS-equipped vehicles in the Aftermarket has led to increased demand on service and repair facilities. Similarly, car manufacturers worldwide continue to require direct TPMS systems that meet their exacting specifications for performance, high-speed valve tolerances, and more. The significant growth in TPMS-equipped vehicles means drivers, service and repair facilities, and vehicle manufacturers are all looking for comprehensive, hassle-free TPMS solutions that won't fail under pressure.
How fast a car can go?
The official land speed record is 763 miles per hour. It is for a short distance run (one mile) and Guinness record is 268 mph. Many countries permit a speed up to 100 mph on their highway for cars and trucks. So, such vehicles are expected to have much higher capability than that.
This is mentioned to show the expectation of performance from a wheel. When we say wheel, we mean the complete assembly viz., tire, a hub, hub cap, rim, wheel cover, required nuts and bolts.
A hub which is the central part of a wheel that connects the axle to the wheel itself. A hubcap, rim, wheel cover or wheel trim is a decorative disk on an automobile wheel that covers at least a central portion of the wheel, called the hub.
An automobile hubcap is used to cover the wheel hub and the wheel fasteners to reduce the accumulation of dirt and moisture. It also has the function of decorating the car.
A "hubcap" is technically the small cover over the center of the wheel, while a "wheel cover" is usually a decorative metal or plastic disk that snaps or bolts onto and covers the entire face of the wheel.
Cars with stamped steel wheels often use a full wheel cover that conceals the entire wheel. Cars with alloy wheels or styled steel wheels generally use smaller hubcaps, sometimes called center caps.
Below is a drawing of wheel assembly of a vehicle.
We are learning about ‘Rim’ on which tire is mounted for use.
A typical rim looks as given below:
Components of a wheel Wheels made of aluminum alloy may feature several different finishes, including polished, painted, machined and chromed. Each finish has a unique look and requires specific maintenance to keep it looking good.
Outboard face: This is the main face of the wheel; what makes up the
design you see on your vehicle. Besides style, the outboard face also
provides structure for the wheel. This section of the wheel is also
commonly known as the ‘spider’.
Center bore: An empty hole in the center of the wheel. The center bore
is often covered by a cap with the manufacturer’s logo so you can’t see it
when the wheel is on the car.
Plate: The central section around the center bore that contains the bolt
holes for the lugs. It bolts to the wheel hub, while the spokes connect the
rim to the plate.
Spokes: The structures that connect from the plate to the edge of the
rim. There are a huge variety of spoke patterns, with different spoke
counts, diameters, lengths, and shapes available. Spokes play a large
part in determining the weight and strength of a wheel.
Rim: Outer diameter of the wheel. When discussing the size of a wheel,
it is usually the rim diameter that is being measured.
Bolt circle: The circle that is created by the centers of the bolt holes,
where the lugs affix the wheel to the hub.
Valve stem bore: Hole that allows air to be added to the tire. The valve
stem itself be made of rubber or metal.
Wheels are made with steel, aluminum alloy or carbon fiber. Steel is
simple, inexpensive but heavy. Aluminum alloy is a proper balance
between strength, weight, durability, and cost. Carbon fiber are light and
strong but very expensive and become useless in a single impact with a
Wheels made of aluminum alloy may feature several different finishes,
including polished, painted, machined and chromed. Each finish has a
unique look and requires specific maintenance to keep it looking good.
As you have seen rim plays a vital role in functioning of a vehicle, from bicycle to aircraft.
Now it is a subject by itself. Our focus is to tire which is a component going with the rim and together we call it as mentioned wheel.
There is no need to go through more than what is relevant to us about rim.
Flaps are used with tube type truck tires. Tube is covered all around by tire except at the bead area where it is open,
Like a tire is integral to the function of a vehicle, a tire flap is essential to the proper performance of a tire. A tire flap refers to the part of the tire that protects the tire tube (which is used to maintain tire air pressure) from rubbing against the tire rim or
from being pushed under the bead toe, therefore preventing the tube from being punctured.
All truck tires used with tubes require flaps. Without tire flaps, the tube remains unprotected from the inside of the wheel and can result in a tire blowout or other form of tire damage that may cause accident injuries or deaths.
Flaps are made with
a rubber compound which is cheaper compared to other rubber compounds. Generally, this compound contains many other compounds rejected from their normal use due to not meeting the specification.
Many small-scale industries are manufacturing them for bigger companies or for direct marketing.
Only in film mud sprayed on clean dress of a young man by a good-looking girl can end in a love. Not in real life.
As per Wikipedia a mud-flap or mud guard is used in vehicle fender to protect the vehicle, passengers, other vehicles, and pedestrians from mud and other flying debris thrown into the air by the rotating tire.
A mud-flap is generally made from a work-away rubber compound, but they are also made colorfully for people who fancy for it.
Quality expected is that it should not get easily damaged by contact with flying debris, the tire, or the road surface.
Mud-flaps are also aerodynamically engineered, utilizing shaping, louvers or vents to improve airflow and lower drag.
In the United States, there are mud-flap regulations that vary from state to state.
Aerodynamic mud-flaps are engineered with louvers or ventilated slats to improve airflow, reduce side-spray, and decrease aerodynamic drag, in order to improve fuel efficiency.
As per google supercomputing technology applied to the problem of semi-trailer truck drag has helped to validate such aerodynamic improvements. Traditional solid truck mud flaps can increase drag, but a study seems to have indicated slatted mud flaps can reduce drag more than 8 percent, making the truck's drag coefficient comparable to one without any mud flaps fitted.
A further advantage of the design is the heat-venting capacity of aerodynamically optimized mud flaps. The improved airflow, commonly engineered into high-performance automobiles, promotes the quick release of otherwise re-circulated water and air from the fender well while improving performance by cooling the tires and brakes.