Gearing up for action

By YAM PHUI YEE THE


heat is on for the country’s debut small formula-style race team as it preps for a big event next month. You can liken it to the Ferrari team in action, the Renault engineers in their top form, and that there are Alonsos and Schumachers in the making. The team in question does not comprise aged hands but is made up of over 40 students from the Universiti Teknologi Petronas Formula Society of Automotive Engineers (UTP FSAE) who are anticipating the adrenaline rush in the Formula SAE Australia to be held in Melbourne, Australia. Also known as Formula Student in Britain, Formula SAE provides aspiring motorsports fans a professional start. The restrictions on the car frame and engine pose a challenge to the knowledge, creativity and imagination of its makers. As such, the cars are usually built over a year and then pitted against other vehicles from other colleges and universities at the annual competition. “Our team consists of students from Mechanical, Electrical and Electronic and Civil Engineering disciplines. In addition, we also have students from Information Communication Technology programme,” said UTP FSAE management head Ng Choon Hoong, 21, who is a mechanical engineering student himself. Planning and preparation works which began two years ago are beginning to take shape and the team even visited their counterparts at the National University of Singapore. “After the visit, we came up with our initial design and the design has been modified and optimised to the final design that we have right now,” he said. Despite their hectic student lifestyle, the students are happily cocooned in a large workspace area where the car morphs from blueprint to reality. Here, minor fabrications, assembly and fine-tuning of the cars are done. “In terms of more technical preparations, a few members from the team have been chosen to undergo a two-month drivers’ training course. Drivers’ training is done using fun-karts during the preliminary stage and an 80cc go-kart for the advanced level. When the car is fully fabricated and functional, the drivers will then be trained using the FSAE car,” explained Ng. The UTP FSAE’s sleek car is called Steel Feather. Technical department head Mohd Faizan Ahmad Zuhdi, 22, explains that it is a replica of a Formula One vehicle.





Universiti Teknologi Petronas Formula SAE members beaming with pride as they pose with their first mock-up car.

Determining The Age of Tire

When it comes to determining the age of a tire, it is easy to identify when a tire was manufactured by reading its Tire Identification Code (serial number). Unlike vehicle identification numbers (VINs) and the serial numbers used on many other consumer goods (which identify one specific item), Tire Identification Codes are really batch codes that identify which week and year the tire was produced.The U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) requires that Tire Identification Code be a combination of eleven or twelve letters and numbers that identify the manufacturing location, tire size, manufacturer's code, and week and year the tire was manufactured.Today, the week and year the tire was manufactured is contained in the last four digits of the serial number, with the 2 digits used to identify the week a tire was manufactured immediately preceding the 2 digits used to identify the year.Examples of tires manufactured since 2000 with this Tire Identification Code format:XXXXXXXX 0600XXXXXXXX 060006 - Manufactured during the 06th week of the yearXXXXXXXX 060000 - Manufactured during 2000AndXXXXXXXX 0604XXXXXXXX 060006 - Manufactured during the 06th week of the yearXXXXXXXX 060404 - Manufactured during 2004The Tire Identification Code for tires produced prior to 2000 was based on the assumption that no tire would be in service for ten years. They were required to provided the same information, with the week and year the tire was built contained in the last three digits. The 2 digits used to identify the week a tire was manufactured immediately preceded a single digit used to identify the year.For example, if the Tire Identification Code on a tire reads:XXXXXXXX 0680XXXXXXXX 060006 - Manufactured during the 06th week of the yearXXXXXXXX 06808 - Manufactured during the 8th year of the decadeWhile the previous serial number format identified that a tire was built in the 8th year of a decade, there was no universal identifier that confirmed which decade (tires produced in the 1990s may have a small triangle following the Tire Identification Code to identify the decade). The Tire Identification Code format used since 2000 accurately confirms the year.And finally, hold on to your sales receipts. Most tire manufacturer's warranties cover their tires for four years from the date of purchase, or five years from the week the tires were manufactured. So if you purchase new tires that were manufactured exactly two years ago they will be covered for a total of six years (four years from the date of purchase) as long as you have your receipt. If you lose your receipt, your tires' warranty coverage will end five years from week the tire was produced (resulting in the tire manufacturer's warranty coverage ending only three years from the date of purchase in this example).

Construction Material

The branding on the sidewall of a tire is required to list the materials and number of layers of each material used to reinforce the rubber.A typical tire's basic construction materials are usually presented as follows:
TREAD 2 POLYESTER + 2 STEEL + 1 NYLON
SIDEWALL 2 POLYESTER
The branding in this example identifies that molded into the rubber under the centerline of the tread lies two radial body plies of polyester cord, two belts of angled steel cord and one circumferential cap ply of nylon cord. It also identifies that in each sidewall at the widest points between the tire's inner and outer sidewalls (tire section width) lies two radial body plies of polyester cord (a continuation of the same two body plies that were listed under the centerline of the tread).
Many high-speed tires use circumferential reinforcements above the steel belts. These are either in the form of belt edge strips (approximately 1-inch wide bands covering only the inner and outer edges of the steel belts), full cap plies (covering the entire width of the steel belts) or a combination of both. However, because belt edge strips are not present under the centerline of the tread, they are never reflected in the basic construction material's branding for the tread area.
Many ultra high performance tires also use fabric or steel cord reinforced sidewalls to increase steering response and cornering stability. However, because sidewall-reinforcing material is not present at the widest points of the tire's sidewalls, they are never reflected in the basic construction materials branding for the sidewall area.

Width x Aspect Ratio = Section Height
Section Height x 2 = Combined Section Height
Combined Section Height + Wheel Diameter = Tire Diameter





Example: 185/60R14 85H or 185/60HR14

185mm x .60=111mm
111mm x 2=222mm
222mm + 355.6mm(14")= 577.6mm or 22.74"

The first number is the width of the tire in millimeters, measured from sidewall to sidewall. To convert to inches, divide by 25.4 In the example above, the width is 185mm or 7.28".

The second number is the aspect ratio. This is a ratio of sidewall height to width. In the example above, the tire is 7.28" wide, multiply that by the aspect ratio to find the height of one sidewall. In this case, 185x0.60=111mm or 7.28"x0.60=4.36".

The last number is the diameter of the wheel in inches.

To figure the outside diameter of a tire, take the sidewall height and multiply by 2,(remember that the diameter is made up of 2 sidewalls, the one above the wheel, and the one below the wheel) and add the diameter of the wheel to get your answer.

Today, UNI-T, UNI-T AQ and UNI-T AQII technologies are available in selected performance, touring, passenger and light truck tires. UNI-T stands for the Ultimate Network of Intelligent Tire Technology, while UNI-T AQ and AQII identifies that the tire also offers Advanced Quality. And while their names don't fully describe what they mean to tire performance...they offer technologies that you probably want your tires to have.
To many drivers, tires appear to be relatively simple rubber products. All they do is bake rubber in a mold until it forms a functional tread design and attractive sidewalls, right?
Wrong! Tires are very complex. They combine dozens of components that must be formed, assembled and cured together. And their ultimate success depends on their ability to blend all of the separate components into a cohesive product that satisfies the driver's needs.




UNI-T: Ultimate Network ofIntelligent Tire Technology
Consists of three core technologies that are the cornerstones of building advanced tires. However, the most important thing about UNI-T isn't what it is...it's what UNI-T does. UNI-T allows tires to offer tuned performance while they roll rounder and last longer.

Tuned PerformanceCOCSComputer Optimized Component System
It's advanced tire design technology. It optimizes the tire's shape, materials, construction and tread design to maximize the tire's key performance areas without accepting the traditional tradeoffs in other performance areas.

Roll RounderO-Bead
A tire's beads secure it to the wheel and inside each bead are steel cables that provide the required strength. O-Bead technology makes the bead "rounder" than traditional manufacturing methods. Rounder beads result in rounder tires that are more stable and ride better.

Last LongerL.L. Carbon
Carbon Black is the basic ingredient that gives rubber strength. L.L. (Long Link) Carbon Black is the result of lengthening the basic carbon black molecule, allowing it to strengthen the tread rubber to increase treadlife and fuel efficiency

Tires are comprised of many layers of rubber, steel and fabric. Due to these different components, your new tires require a "break-in" period to ensure that they deliver their normal ride quality and maximum performance. As tires are cured, a "release lubricant" is applied to prevent them from sticking in their mold. Some of the lubricant stays on the surface of your tires, reducing traction until it is worn away. Five hundred miles of easy acceleration, cornering and braking will allow the mold release lubricant to wear off, allowing the other tire components to begin working together. It is also important to note that your old tires probably had very little tread depth remaining when you felt it was time to replace them. As any autocrosser or racer who has tread rubber shaved off of his tires will tell you "low tread depth tires respond quicker." Don't be surprised if your new tires are a little slower to respond (even if you use the exact same tire as before). Their new, full depth brings with it a little more tread squirm until they wear down.



NOTE: Be careful whenever you explore the capabilities of your new tires. Remember that every tire requires a break-in period for optimum performance.

TYRE DEFECT ANALYSIS REPORT



Nature of complaint :
Tyre burst during inflation after it has just been repaired at tread region due to puncture. The

explosion arising from tyre burst has caused injury to tyreman. The incident has also been

reported in local newspaper.



FINDINGS



Tyre Size : 295/80R22.5 Steel King 988Serial Number : 0941GLJ (3505)Pattern Depth Remaining : 7.4mm (37%)Dealer : Simpangan Kurnia, Bahau, N.Sembilan.Complaint : Sidewall burst during inflation after tyre had just been repaired at tread due to puncture.Bitmap
Outside viewSteel body ply wire break circumferentially. No separation between sidewall rubber andsteel body wire was noted.
Zipper Break Failure - Steel wire snapped byexternal force in zipper shape, sharp edges of broken wire was the evident. A common failurein overloading or underinflation operating condition. Bitmap
Tread has been damaged by external object and repaired was done at internal cavity.
Punctured Repair
Stress markobserved at inner-liner. Evidence ofrunning under insufficient pressure.Bitmap 2, 59, 30, 5, 6, 55, 36, 7
Inside viewSteel body ply wire break circumferentially. No separation was noted.



CONCLUSIONS

The tyre has encountered a damaged puncture at tread region that lead to air leak. The air leak has caused an
underinflated condition (same phenomenon to overloading condition) to the tyre, in which under this abnormal service
condition, the steel body ply cords at mid sidewall region are subjected to very excessive flex and high stress and soon
became fatigue and weaken. The fatigue steel wire cords may not be visualised during puncture repairing. However,
when the tyre was inflated, the weakening steel cords were not able to withhold the high inflation pressure, lead to
tyre blow out/burst.

If the subject tyre was fitted as a dual fitment (high possibility as it was SK988 pattern - drive axle tyres), during
the subject tyre encountered air leak, its partner may suffered an overloading situation. The severity was subject to how
long the truck has been travelling under this abnormal service condition, before reaching the tyreshop. In other words,
the other tyre may also potentially encountered fatigue steel cords that may lead to zipper break failure in later stage.
Lastly, Dealers need to be advised to handle with care when inflating AST tyres that been repaired or run-flat.

Maintenance Tips to Increase Tire Performance, Life and Durability

Check and Adjust First Thing In The Morning. Set according to the vehicle manufacturer's cold tire pressure(s) recommended on the vehicle's tire placard or in its owner's manual. This must be done before rising ambient temperatures, the sun's radiant heat or even driving short distances temporarily warms the tires.

Accommodating Variables

Indoor-to-outdoor Temperature Variation. Significant differences between the conditions tire pressures are set (the warmth of an attached garage, heated garage or service shop) and in which the vehicle will be driven (winter's subfreezing temperatures) requires inflating tires 1 psi higher than recommended on the placard for every 10° F difference in temperature between interior and exterior temperatures.
Afternoon Ambient Temperature Increase.* Set 2 psi above vehicle manufacturer's cold inflation recommendations when installing new tires or if the vehicle has been parked in the shade for a few hours.

Tire Heat Generated While Being Driven (or at speeds of less than 45 mph).* - Set 4 psi above vehicle manufacturer's cold inflation recommendations.
Heat Generated While Being Driven Extensively (or at sustained speeds greater than 45 mph).* Set 6 psi above vehicle manufacturer's cold inflation recommendations.
Do Not Release Hot Tire Pressure if any of these variables could be the cause of measured tire pressure exceeding the maximum psi branded on the tire's sidewall by the 2, 4 or 6 psi indicated above for the various conditions. This temporary pressure increase is expected and designed into the tire's capabilities.

*NOTE: Tires on a parked vehicle exposed to direct sunlight will appear overinflated due to the heat absorbed from the radiant energy of the sun. Pressures cannot be accurately set on these tires until all have stabilized in the shade.

Air Pressure/Load Adjustment for High Speed Driving

Driving at high speeds certainly helps make a trip go faster; just ask any driver who has gone "flat out" on the German Autobahn. However with the exception of events like the Silver State Classic's Open Road Rally or a driver's school on a racetrack, it's difficult to find a place that allows unlimited speeds! Remember, the tires on the vehicle should be properly sized, inflated and inspected if you plan to drive fast because the tires will be subjected to tremendous stresses.
Because of the weight they bear, pneumatic tires' sidewalls bulge and their treads flatten as they roll into contact with the road. This results in dimensional difference between the tire's "unloaded" radius (i.e., between the center of the axle and the top of the tire) and its "loaded" radius (between the center of the axle and the road). The engineer's call the difference between the two radii "deflection." Increasing vehicle speed will cause the tires to deflect quicker and increasing vehicle load will cause the tires to deflect farther (if tire pressure isn't increased).
Consider that a 225/45R17 91W Standard Load tire (with a 25-inch overall diameter) will roll about 835 times every mile. Although the number of tire revolutions per mile doesn't change significantly as speed climbs, the revolutions per second become daunting. While the 225/45R17 91W-sized tire rolls a rather comfortable 7 times per second at 30 mph, this same tire will roll about 16 times per second at 70 mph on an American Interstate and an amazing 35 times per second during a 150 mph cruise on the German Autobahn. Thirty-five tire revolutions per second means that the tire is transforming from its unloaded to loaded shape and back every 3/100th of a second.
The European Tyre and Rim Technical Organization (ETRTO) establishes the standards for tires sold in Europe, and recognizes that the tire's deflection must be minimized and controlled in order to surpass high speed driving stresses. In order to accomplish this, the tire inflation pressure recommendations and the tire's rated load capacities are customized when speeds exceed 160 km/h (99 mph) for all tires up to and including a V-speed rating, and when speeds exceed 190 km/h (118 mph) for all tires that are Z-speed rated and above.
The Autobahn's unlimited speed opportunities explain why many German vehicles identify alternate tire inflation pressures to accommodate higher than North American highway speeds and heavier than typical two-passenger loads. In order to accommodate higher speeds, the tire size and inflation pressure recommendations are tuned beyond what is branded on the tire's sidewalls. These increases in recommended tire pressure are usually determined by agreement between the vehicle and tire manufacturers. In the absence of such an agreement, apply the following:
Beginning with the vehicle manufacturer's recommended tire pressure for normal highway conditions, tire inflation pressures are initially increased and then the tire's rated load capacities (branded on the sidewalls) are reduced as speeds climb.
In our example shown below, the vehicle manufacturer's recommended 35 psi for a 225/45R17 91W Standard Load tire installed on a vehicle initially rises in 1.5 psi increments for every 10 km/h (6.2 mph) increase in speed until the inflation pressures max out with an increase of 7.5 psi when the vehicle's top speed has increased 50 km/h (31mph). Then as the vehicle's top speed continues to climb, the rated load capacity of the tire is reduced in 5% increments for every additional 10 km/h until the vehicle's top speed has increased an additional 30 km/h (18.6 mph). In this case the 225/45R17 91W Standard Load size's rated load capacity of 1,477 lbs. is reduced to 1,255 lbs. when applied to a vehicle with a 270 km/h (168 mph) top speed.

Air Pressure, Time Fluctuations

Your tires support the weight of your vehicle, right? Well they don't! It's the air pressure inside them that actually supports the weight. Maintaining sufficient air pressure is required if your tires are to provide all of the handling, traction and durability of which they are capable.
However, you can't set tire pressure...and then forget about it! Tire pressure has to be checked periodically to assure that the influences of time; changes in ambient temperatures or small tread punctures have not caused it to drop.
While tires appear solid, the molecular structure of the rubber used to manufacturer them actually looks like strands of cooked spaghetti stuck together. These molecular strands are stretched and returned to their relaxed state every time the tire rolls (about 800 times every mile).
Since typical tire pressures range from 30 to 35 psi for cars (with light truck tire pressures often higher), there is a constant force trying to push the air through the tire. This allows some of the air to escape (called permeation) right through the microscopic spaces between the rubber molecules. And somewhat like a rubber balloon, the air will eventually escape if it is not replenished.
All things being equal, a tire's inflation pressure will go down by about 1 psi every month. This means that if air isn't added for two to three months, the tire's inflation pressures will probably be 2 to 3 psi low.
Tires are normally inflated with air (a combination of gasses comprised of about 78% nitrogen (N2), 21% oxygen (O2) and 1% argon (Ar) along with traces of other gasses) from the local gas station. Unfortunately, using air permits moisture and the amount of water vapor in the air varies from place to place, time of the year and due to weather conditions. While air is all around us, finding a convenient source of compressed air is becoming difficult, and finding a source of "dry," vapor free compressed air is even more difficult.
In order to help maintain more constant tire pressures we should check them more frequently. Once a month and before trips is the minimum, once a week is preferred. This will allow us to refill lost pressure that escapes over time, as well as discover any pressure losses due to slow leaks caused by minor punctures before significant pressure is lost and the tire's internal structure is damaged.

Your tires support the weight of your vehicle, right? Well they don't! It's the air pressure inside them that actually supports the weight. Maintaining sufficient air pressure is required if your tires are to provide all of the handling, traction and durability of which they are capable.
However, you can't set tire pressure...and then forget about it! Tire pressure has to be checked periodically to assure that the influences of time; changes in ambient temperatures or that a small tread puncture has caused it to change.
The tire pressure recommended in your vehicle's owner's manual or tire information placard is the vehicle's recommended cold tire inflation pressure. This means that it should be checked in the morning before you drive more than a few miles, or before rising ambient temperatures or the sun's radiant heat affects it.
Since air is a gas, it expands when heated and contracts when cooled. In most parts of North America, this makes fall and early winter months the most critical times to check inflation pressures...days are getting shorter...ambient temperatures are getting colder...and your tires' inflation pressure is going down!
The rule of thumb is for every 10° Fahrenheit change in air temperature, your tire's inflation pressure will change by about 1 psi (up with higher temperatures and down with lower).
In most parts of North America, the difference between average summer and winter temperatures is about -50° Fahrenheit...which results in a potential loss of about 5 psi as winter's temperatures set in. And a 5 psi loss is enough to sacrifice handling, traction, and durability!
Additionally, the difference between cold nighttime temperatures and hot daytime temperatures in most parts of the country is about 20° Fahrenheit. This means that after setting tire pressures first thing in the morning, the vehicle's tire pressures will be almost 2 psi higher when measured in the afternoon (if the vehicle was parked in the shade). While that is expected, the problem is when you set your vehicle's tire pressures in the heat of the day, their cold pressures will probably be 2 psi low the following morning.
And finally, if the vehicle is parked in the sun, the sun's radiant heat will artificially and temporarily increase tire pressures.
We put some of these theories to the test at The Tire Rack. First, we mounted two tires on wheels. We let them sit overnight to equalize and stabilize their temperatures and pressures. The following morning we set them both to 35 psi. One tire and wheel was placed in the shade while the other was placed directly in the sun. We then monitored the ambient temperatures, tire temperatures and tire pressures through the day. As the day's temperatures went from 67° to 85° Fahrenheit, the tire that was kept in the shade went from our starting pressure of 35 psi to a high of 36.5 psi. The tire that was placed in the sun and subject to the increase in ambient temperature plus the sun's radiant heat went from our starting pressure of 35 psi to a high of 40 psi. In both cases, if we had set our tire pressures in the afternoon under the conditions of our evaluation, they would have been between 2 and 5 psi low the following morning.
Next we evaluated the affects of heat generated by the tire's flexing during use. We tried to eliminate the variable conditions we might encounter on the road by conducting this test using our "competition tire heat cycling service" that rolls the tires under load against the machine's rollers to simulate real world driving. We monitored the changes in tire pressure in 5-minute intervals. The test tires were inflated to 15 psi, 20 psi, 25 psi and 30 psi. Running them all under the same load, the air pressure in all of the tires went up about 1 psi during every 5 minutes of use for the first 20 minutes of operation. Then the air pressures stabilized, typically gaining no more than 1 psi of additional pressure during the next 20 minutes. This means that even a short drive to inflate your tires will result in tires that will probably be under-inflated by a few psi the following morning.
Add all of these together, and you can understand why the conditions in which you set your vehicle's tire pressures are almost as important as the fact that you do set it.
It's important to remember that your vehicle's recommended tire pressure is its cold tire inflation pressure. It should be checked in the morning before you drive more than a few miles, or before rising ambient temperatures or the sun's radiant heat affects it.
And by the way, if you live in the North and park in an attached or heated garage you will lose pressure when you leave its warmth and venture into the real world outside during winter. Add 1 psi cold pressure tire pressure to compensate for each 10° Fahrenheit temperature difference between the temperature in the garage and outside.

Most drivers realize that tire load capacity is determined by tire size and inflation pressure. Larger tires and higher inflation pressures provide more load capacity, while smaller tires and lower tire pressures provide less.
Correctly inflated tires receive appropriate support from the contained air pressure to provide an even distribution of load across the footprint and help stabilize the tire's structure. And while most drivers recognize that this has a significant impact on tire wear, rolling resistance and durability, only a few realize underinflation also has a noticeable influence on how quickly and precisely the tires respond to the driver's input.
In order to evaluate the influence of inflation pressure on response and handling, The Tire Rack conducted a Performance Test Track Drive, comparing properly inflated tires to purposely underinflated tires. We used 2003 BMW 330Ci coupes, and installed P225/50R16 tires on 16x7.5" wheels. We tested new, full tread depth tires.
We chose Goodyear Eagle GT-HR High Performance All-Season radials that were developed to blend good treadwear, responsive handling and dependable traction. One of the Eagle GT-HR's highlights is its internal construction that features Goodyear's RaceWrap Construction Technology developed for the Eagle Race tires used in NASCAR competition. RaceWrap Construction Technology brings a casing ply down the sidewall at a slight angle, wraps around the bead and returns it all of the way up the sidewall until it ends under the edge of the steel belts. This slightly angled, two-ply sidewall enhances steering response and handling stability.
The tires installed on one of our BMW 330Ci test cars were inflated to the vehicle manufacturer's recommended inflation pressures of 29 psi front and 33 psi rear, while the other car had its tires inflated 30% lower (20 psi in the front and 23 psi in the rear). We chose 30% underinflation because it was the percentage of loss initially established by the US DOT at which passive pressure monitoring systems must warn the driver of low inflation pressure on future cars.
The first part of the test was visual. We asked the drivers to look at the tires and decide which of the two vehicles was equipped with the underinflated tires. While perhaps this visual test might have been easier with taller tires of the past, today's low profile tires fitted to the BMWs demonstrated how difficult it has become. The drivers agreed that the tire appearance alone did not provide irrefutable confirmation of the tire pressure contained inside. You can't use your eyes as a tire pressure gauge.
Can you easily identify which tire is 30% underinflated with your eyes? Here is what they would look like in the morning as you walked to your car in the garage.
(Roll your mouse across the pictures to confirm you were right)



The next test was run on our test course to confirm the influence of tire pressure on the tire's performance at its limit. While the drivers thought that the properly inflated tires provided responsiveness and predictable handling, they quickly realized that the same tires in an underinflated state left a lot to be desired. The underinflated tires required more steering input to initiate maneuvers and were slower to respond. The underinflated tires also felt out of sync during transitions; instead of moving in unison, the rear tires' reactions lagged behind the front tires, resulting in a detached sensation being transmitted to the drivers.
The underinflated tires delivered acceptable steady-state cornering force once they stabilized on our test track's skid pad, but the car was uncooperative anytime it was asked to change directions. It proved to be over 2 seconds slower around our test course (2 seconds represents about a 7% loss of handling performance).
In other words, the performance that tire manufacturers build in, low tire pressures can take away.
Adjust your tire pressures as indicated on the vehicle tire placard or in the owner's manual. Check you inflation pressures at least once a month and before highway trips.

John Boyd Dunlop

Tyres as we know them have been around for well over 100 years, it started in 1845 when Scotsman Robert Thompson first came up with the idea of an air filled chamber mounted on the outside of a wheel.

Unfortunately with few practical applications to drive it forwards and limited funds the idea faded away. Then in December 1887, another Scotsman, John Boyd Dunlop was watching his son ride his tricycle across an uneven stone cobbled yard and thought how much easier it would be if the wheels were soft and could absorb the bumps. He made a wooden disk and mounted an air filled rubber tube covered with linen cloth on the outside and the tyre industry was born.



Beaded edge tyres

Many different methods were thought of to mount the tyre onto a wheel and many patents were lodged with claims and counter claims from various companies. However, the most popular tyre design to come out was the beaded edge system (popular between 1890-1925), the tyre had a groove on its side which corresponded with a ridge or clinch on the wheel rim and was held in place with the pressure of air within it, which had to be maintained at sometimes up to 100 psi.
In Europe these tyres were measured in millimetres, in America they were measured in inches and were called Clincher tyres. The measurements referred to the overall tyre dimension and bore no reference to the wheel rim diameter. This system was widely used on both cars and motorcycles up to the mid 1920's when they were superseded by the wired-on system.