4.4.2 Description and operation 

4.4.2.1 Tire structure 

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3

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6

2

5

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1. Tire 

tread 

The part of the tire contacts with the road surface, enabling the vehicle with the performances of driving and 
braking through friction, shall have good abrasion resistance, puncture resistance, impact resistance, cooling and 
other performances. 

2. Tire 

body 

The cord ply in the tire is the main forced component of the tire, which has impact resistance and good flexibility 
resistance in traveling. 

3. Belt 

The steel cord between the tire tread and the tire body protects the tire body, inhibits the tire tread from deforming 
and maintains the grounding surface of the tire tread, thereby improving the wear resistance and driving stability. 

4. Cap 

ply 

Special cord plies above belt layer prevent the belt layer from moving when tires are running, so that the belt layer 
is prevented from tripping when running at high speed to keep the stability of the tire size under the state of high 
speed. 

5. Tire 

thread 

Hanging plastic steel wire is wound by a certain shape (quadrilateral or hexagonal shape) to play the role in fixing 
the tire by rim. 

6. Apex 

strip 

The filling material above the ring traveler in the tire prevents the tire bead from dispersing, retard the tire bead 
impact, protect the tire bead and prevent air from entering at the time of molding. 

7. Inner 

liner 

 

The part of the tubeless tire for maintaining the air impermeability is made of special rubber, which is equivalent 
to the role of the inner tube. 

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4.4.2.2 Tire side mark means of tire and air pressure specification 

Meaning of tire side wall identification 

For example: 225/65 R17 102H 

225—Nominal section width (unit: mm) 

65—Flattening(depth-width ratio:％) 

R—Meridian structure 

17.  Nominal wheel hub diameter (unit: in) 

102—load Index 

H—Speed class (210 km/h) 

Common speed class mapping table: 

Speed grade 

S T H V W Y 

ZR 

Max. speed (km/h) 

180 190 210 240 270 300 

Above 

240 

Description of tire pressure 

The tire pressure has decisive effect on the tire wear, fuel consumption and fault damage; therefore, the standard 
pressure must be maintained and the air pressure must be checked regularly in order to drive safely. 

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Loading capacity of tire is corsponding to its inflation pressure, so it is necessary to determine the rational air 
pressure according to the loading capacity of the vehicle.  The climate and seasonal changes should not be 
the reason to adjust the tire pressure. 

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In initial use of new tire, external rim dimension of tire will change due to the heating produced by yield 
movement, which will lower the air pressure of tire. 

Therefore, it is necessary to inspect and adjust air 

pressure tire during 24h use or after traveling 2,000-3,000km. 

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If traveling at high speed for a long time, tire air pressure should be increased by 10%-15%. 

1. Risk 

of 

insufficient air pressure. 

Insufficient air pressure will result in aggravating the deformation of the tire side wall, increase heat 
generation, greatly shorten the service life of the tire, and bring about the following problems and 
potential safety hazard; 

a. 

The tire shoulder is excessively worn. 

b. 

The opportunity for bulking of the tire under impact is increased 

c. 

Reduction in adhesive force between all components of the tire results in delamination. 

d. 

Severely insufficient pressure causes the side tire wall to be damaged due to being compressesd. 

e. 

Excessive tire run-out causes abnormal wear between the tire bead and hub which damages the 
hub. 

f.    The oil consumption will increase with the increase in rolling resistance. 

2. 

Harmness of excessive air pressure. 

Insufficient air pressure will result in ground contact area reduced of the tire tread, increase the tire 
rigidity, reduce the buffer, and bring about the following problems and potential safety hazard; 

a. 

The middle area of the tire tread is excessively worn. 

b. 

The risk of breakage and even burst when the tire is impacted by external force is increased. 

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c. 

Maneuverability degradation resulting from the reduction in ground contacting area easily results 
in the risk of drift, sliding, etc. 

d. Degraded 

passenger 

comfort 

e. 

Low riding comfort and traveling with excessive tire pressure for a long time easily damage the 
chassis. 

3. 

Nonuniform tire pressure on the same suspension may cause: 

a. 

The braking force is unbalanced on the left and right sides. 

b. Steering 

deviation 

c. Maneuverability 

degradation 

d. 

Deviation during acceleration 

e. 

The vehicle deviates during travelling. 

4.4.2.3 Tire rotation 

Wear varies greatly between the front and rear wheels depending upon the loads thery withstand during operation, 
so to avoid tire from being subject to uni-directional wear you should perform tire rotation at the appropriate time 
periodically to make tire wear even and in turn extend the life of the tire. 

Recommend to replace once every 5,000-8,000 km, with the main purpose of tire rotation as follows: 

A.  Ensure the tire is evenly worn and the fatigue of the tire is averaged to ensure the stability and economicality. 

B.  During tire exchange, check the tire condition to identify damages in time and thus prevent against the 

occurrence of accidents. 

Tire rotation method is as shown in figure: 

  Rotation after use of spare tire 

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Parallel Rotationand coordinated rotationmethod refer to 1.4.2.5 description of tire transposition. 

 

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