TiresTiresTires have several characteristics Tires have several characteristics that are important in that are important in understanding their design. understanding their design. Red = on unit testRed = on unit test

Tire VocabularyTire Vocabulary

1.1. BeltBelt 9.9.PatchPatch

2.2. HydroplaningHydroplaning10.10.BeadBead

3.3. Radial-plyRadial-ply 11.11.TreadTread

4.4. Bias-plyBias-ply 12.12.Uniform tire quality Uniform tire quality

5.5. ProfileProfile grading system grading system

6.6. Aspect ratio Aspect ratio 1313.Inflation.Inflation

7.7. Load indexLoad index 14.14.Load rangeLoad range

8.8. Drop centerDrop center 15.Tread 15.Tread wear indicatorwear indicator

Tire CharacteristicsTire Characteristics

Traction : dry, wet, mud, ect Traction : dry, wet, mud, ect Ride – comfort & feedbackRide – comfort & feedback Handling - responseHandling - response Rolling resistance – fuel economyRolling resistance – fuel economy NoiseNoise Tread wearTread wear High speed capabilityHigh speed capability

Taping a rubber tree Taping a rubber tree to get natural rubber.to get natural rubber.

Synthetic rubberSynthetic rubber

Most of the rubber used in Most of the rubber used in modern tires is synthesized in a modern tires is synthesized in a laboratory.laboratory.

Tire construction:Tire construction: The BEAD The BEAD

The bead is made of about 10 strands The bead is made of about 10 strands of 16 gauge steel wire wrapped in a of 16 gauge steel wire wrapped in a circle.circle.

The cord material in the body of a The cord material in the body of a belted radial or radial ply tire runs belted radial or radial ply tire runs from one bead to the other across the from one bead to the other across the top of the tiretop of the tire

The bead acts like a foundation for the The bead acts like a foundation for the ply and the rest of the structure.ply and the rest of the structure.

The PLY STRUCTUREThe PLY STRUCTURE

Gives strength to the tire.Gives strength to the tire. Made up of nylon, polyester or other Made up of nylon, polyester or other

flexible fabric.flexible fabric. Number of ply’s determines strength / Number of ply’s determines strength /

stiffness of sidewall and load capacity stiffness of sidewall and load capacity of the tire.of the tire.

Can be radial or biasCan be radial or bias Bias ply tires are old technology and Bias ply tires are old technology and

hard to find.hard to find.

The SIDE WALLThe SIDE WALL

The side wall supports the weight of The side wall supports the weight of the vehicle.the vehicle.

The Aspect ratio & # of Ply’s affect the The Aspect ratio & # of Ply’s affect the stiffness of the sidewall. stiffness of the sidewall.

All tire parts are Vulcanized. All tire parts are Vulcanized. Vulcanizing is the process of heating Vulcanizing is the process of heating rubber under pressure to mold the rubber under pressure to mold the rubber and help it flow and bond with rubber and help it flow and bond with other tire parts.other tire parts.

The BeltsThe Belts

Located directly under the treadLocated directly under the tread Made of steel, fiberglass or Made of steel, fiberglass or

another composite material.another composite material. Sometimes called “under tread”Sometimes called “under tread” The Belts support and give The Belts support and give

strength to the tread.strength to the tread.

The Inner LinerThe Inner Liner

Seals the inside of the tire so it Seals the inside of the tire so it will not seep air.will not seep air.

Acts like an inner tubeActs like an inner tube Never use an inner tube on a Never use an inner tube on a

tubeless tire.tubeless tire.

The FillersThe Fillers

Reinforces the area around the Reinforces the area around the tire bead .tire bead .

Sometimes called chafer stripsSometimes called chafer strips

Tire ValveTire Valve

Used to put air Used to put air through the rim through the rim into the tire.into the tire.

Contains a small Contains a small valve that can be valve that can be removed or removed or depressed to depressed to release air from release air from tire. tire.

Load RangeLoad Range

All tires have a maximum safe All tires have a maximum safe carrying capacity. The load range is carrying capacity. The load range is indicated with letters of the alphabet.indicated with letters of the alphabet.

Load range A = approx 750lbsLoad range A = approx 750lbs Load range B = approx 1300lbsLoad range B = approx 1300lbs Load range E = approx 3000lbsLoad range E = approx 3000lbs Load range will be on sidewall of tire. Load range will be on sidewall of tire.

UTQGSUTQGS

UTQGS stands for : Uniform tire UTQGS stands for : Uniform tire quality grading system.quality grading system.

This system is used to rate the This system is used to rate the tires quality in three categories: tires quality in three categories:

1.tread wear1.tread wear 2. temperature resistance2. temperature resistance 3. traction 3. traction

UTQGSUTQGS

By law all ratings are molded into the By law all ratings are molded into the sidewall of the tire.sidewall of the tire.

Tread wear rating : the higher the # Tread wear rating : the higher the # the longer the tread life. 180 is the longer the tread life. 180 is common #. 180 = around 40,000MI of common #. 180 = around 40,000MI of life.life.

Traction rating: A B C. A is best (in Traction rating: A B C. A is best (in wet weather)wet weather)

Temp resistance rating : A B C. A is Temp resistance rating : A B C. A is best (tires ability to not build heat) best (tires ability to not build heat)

Speed rating Speed rating

The highest speed the tire should The highest speed the tire should be continually operatedbe continually operated

N= 87 mphN= 87 mph H=130mphH=130mph ZR = above 149mphZR = above 149mph y = 186 mph y = 186 mph

Tire InformationTire Information

By law all tire info must be on the By law all tire info must be on the placard and embossed into the placard and embossed into the sidewall of the tire.sidewall of the tire.

Tire placard

Identifying tire sizeIdentifying tire size

The metric tire size system is the The metric tire size system is the most common.most common.

An alpha/numeric system is used An alpha/numeric system is used to describe the tire.to describe the tire.

This info is always printed on the This info is always printed on the side of the tire.side of the tire.

Often the largest letters & Often the largest letters & numbers on the side of the tire.numbers on the side of the tire.

Metric tire size system:

Example: P 205 55 zR 14 Example: P 205 55 zR 14 TheThe P stands for: Passenger car stands for: Passenger car The The 205205 is the tires section width is the tires section width The The 5555 stands for: Aspect ratio stands for: Aspect ratio

55% of section width is section height55% of section width is section height The The ZZ stands for: tire speed rating stands for: tire speed rating The The R R stands for: Radial tirestands for: Radial tire The The 14 14 stands for: Rim diameter stands for: Rim diameter

(inches) (inches)

Tires Part 2Tires Part 2

Safety RimsSafety Rims

Safety rims have small ridges Safety rims have small ridges built into rimbuilt into rim

These ridges are to keep the tire These ridges are to keep the tire on the rim at all times.on the rim at all times.

The tire bead must be forced over The tire bead must be forced over the safety ridges to remove the the safety ridges to remove the tire from the rim.tire from the rim.

Dropped CenterDropped Center

The center of the wheel is made The center of the wheel is made so it has a smaller diameter than so it has a smaller diameter than the rim.the rim.

The wheel has a dropped center The wheel has a dropped center so the tire can be removed so the tire can be removed without damaging the bead.without damaging the bead.

During removal & installation the During removal & installation the bead of the tire must be pushed bead of the tire must be pushed into the dropped area .into the dropped area .

Tire InflationTire Inflation

Over inflation of Over inflation of tires increase tire tires increase tire tension and tension and prevents proper prevents proper deflection of the deflection of the sidewalls.sidewalls.

This results in This results in wear in the center wear in the center of the tread. of the tread.

Tire InflationTire Inflation

Under inflation is Very dangerous!Under inflation is Very dangerous! A tire that is under inflated will build A tire that is under inflated will build

excess heat. This will cause the tire to excess heat. This will cause the tire to de-laminate or de-vulcanize.de-laminate or de-vulcanize.

Tire wear will be dramatically increased!Tire wear will be dramatically increased! Follow recommended inflation pressures Follow recommended inflation pressures

on tire side wall.on tire side wall. Fuel mileage will suffer.Fuel mileage will suffer. All Tires will slowly leak air.All Tires will slowly leak air.

De-vulcanizing due to De-vulcanizing due to under inflation. under inflation.

Tire ProblemsTire Problems

Dynamic BalancingDynamic Balancing

When a tire is spinning it tends to When a tire is spinning it tends to move from side to side if it is out move from side to side if it is out of balance. of balance.

Wheels that are not balanced Wheels that are not balanced cause the car to shimmy or cause the car to shimmy or vibrate when moving.vibrate when moving.

To dynamically balance a tire To dynamically balance a tire weights are placed on both sides weights are placed on both sides of the rim. of the rim.

Static balancingStatic balancing

Static balancing is done by Static balancing is done by placing weight on one side of the placing weight on one side of the tire only.tire only.

A tire badly out of static balance A tire badly out of static balance will jump up and down as the tire will jump up and down as the tire go’ s down the road. go’ s down the road.

Tread wear indicatorsTread wear indicators

Tread wear indicators are a raised Tread wear indicators are a raised portion of rubber in the tires portion of rubber in the tires grooves. When the tire wears to grooves. When the tire wears to approx 4/32 of an inch a solid bar approx 4/32 of an inch a solid bar forms across the tread surface.forms across the tread surface.

When any part of the bar is even When any part of the bar is even with the tread the tire is no longer with the tread the tire is no longer legal to use. legal to use.

Tread wear IndicatorTread wear Indicator

Tire Alignment Tire Alignment

Problems with tire alignment will Problems with tire alignment will cause the tires to wear cause the tires to wear excessively.excessively.

Camber wear will cause wear on Camber wear will cause wear on the shoulder of the tire.the shoulder of the tire.

Toe wear will cause a scuffing or Toe wear will cause a scuffing or feather edge to occur on the edge feather edge to occur on the edge of the tread blocks. of the tread blocks.

Tire alignment wear Tire alignment wear patterns.patterns.

Camber wearCamber wear

Checking Toe AngleChecking Toe Angle

Tire RotationTire Rotation

Rotating tires will Rotating tires will maximize there maximize there life.life.

Front tires tend to Front tires tend to wear more than wear more than backs (unless backs (unless you’re a teen in a you’re a teen in a muscle car)muscle car)

There are two There are two recommended recommended rotations.rotations.

Lug nut torque.Lug nut torque.

Lug nuts hold your wheel-tire assembly on Lug nuts hold your wheel-tire assembly on your car.your car.

Always use a Torque wrench to tighten Always use a Torque wrench to tighten your wheel lugs.your wheel lugs.

Look up torque spec,s in a reference Look up torque spec,s in a reference source. source.

Typical torque spec,s: small car: 80 Ft. Typical torque spec,s: small car: 80 Ft. lbs. Large car or truck 100 Ft. lbs. + lbs. Large car or truck 100 Ft. lbs. +

To tight = broken wheel studs. To loose = To tight = broken wheel studs. To loose = wheel comes off vehicle. Look up those wheel comes off vehicle. Look up those spec,s. spec,s.

Tire RepairTire Repair

When a puncture When a puncture occurs in a tire it occurs in a tire it can typically be can typically be repaired by repaired by patching or in the patching or in the case of a large case of a large hole be plugged.hole be plugged.

Never repair a tire Never repair a tire with structure with structure damage.damage.

Remove nail or screw Remove nail or screw only after marking on only after marking on inside & outside of tire.inside & outside of tire.

Results of Patching a Results of Patching a structurally damaged structurally damaged tire:tire:

You can not patch the You can not patch the sidewall of a tiresidewall of a tire

The sidewall flexes to much The sidewall flexes to much and the patch will likely fail!and the patch will likely fail!

Lift & support the Lift & support the vehicle your working vehicle your working on safely !!! on safely !!!

Good luck with your Good luck with your tire test!tire test!