Tyres

Question 1

What are the different layers of a tyre?

Answer 1

Tyre casing 
Ply 
Bead
Belt
Breaker 
Sidewall 
Tread 
Chafer

Question 2

What are the 2 types of tyre construction?

Answer 2

Cross ply

Radial plus

Question 3

What is cross ply?

Answer 3

Where the plies cross each other at an angle

Question 4

What is radial ply?

Answer 4

Plies are laid from bead to bead

Question 5

What are the different types of tread pattern?

Answer 5

Standard
Cross country
Dual purpose
Winter

Question 6

What would 215 50 H 15 on the side of a tyre mean? (Just the first 2 numbers)

Answer 6

215 mm wide

50 is 50percent of width is the side wall

Question 7

On a tyre what dose T mean?

Answer 7

Speed

Question 8

What would 16 PR mean?

Answer 8

This is the ply rating

Question 9

If you saw 5-14 on a tyre what would this show?

Answer 9

5- width in inches
- = cross ply
14 = diameter in inches

Question 10

What are 3 advantages of cross ply?

Answer 10

Lighter steering at low speeds
Smoother ride at low speeds
Cheaper than radial ply tyres

Question 11

What are the advantages of radial ply tyres?

Answer 11

Longer life
Full width of tread if on road improving grip
Lower rolling resistance
Better fuel economy

Question 12

What is good about a run flat tyre?

Answer 12

Designed to stay on longer when air pressure is lost

Stiffer sidewalls up to 50%

Tyre bead designed to grip wheel rim

Question 13

How dose a bead lock system work?

Answer 13

A bead is fitted to help keep the tyre on the wheel rim

Question 14

What does a well filler or safety band do?

Answer 14

It prevents beads from falling into well

Question 15

How does a run flat core work?

Answer 15

Assumes load bearing function of the tyre

Question 16

What tread should your tyre have on it? (Car)

Answer 16

At least 1.6mm on 3 quarters

Question 17

What tread should your tyre have on it? (HGV)

Answer 17

At least 1mm around tyre, middle or either side

Question 18

How much of a cut would make a tyre US?

Answer 18

More than 25mm long
10% of the section width
Deep enough to reach ply or cords

Question 19

What driving damage could cause damage to tyre?

Answer 19

Rapid acceleration 
High speed cornering 
Sidewall impact (kerbing)
Sudden or excessive breaking 
Incorrect usage of 4 wheel drive

Question 20

How can you identify incorrect wheel alignment?

Answer 20

Feathered edge of rubbing on edges of tread

Worn steering joints and linkages

Question 21

How big can penetrations be in a light vehicle for units to repair?

Answer 21

Up to 6mm in area T

Question 22

What size penetrations can units repair on heavy commercial?

Answer 22

Up to 10mm in area T

Question 23

What type of repairs can we not use? And what type can we use?

Answer 23

Plugs or injection sealants = prohibited

Plug/patch (Mushroom) = only

Question 24

What are the 3 functions of a tread?

Answer 24

Water dissipation
Protect tyre casing
Provide grip