Braking and Tyres

Question 1

Drum and Shoe

Answer 1

Shoes are forced radially onto the drum of the wheel.

Question 2

Advantages of Drum Brakes

Answer 2

Handbrake is easily integrated
Weatherproof

Question 3

Disadvantages of Drum Brakes

Answer 3

Poor cooling: as drum gets hot it expands reducing braking effect.

Question 4

Disc and Caliper

Answer 4

Most common type
Seperate disk from wheel calipers fit over it which are actuated by hydraulic pressure

Question 5

Tread

Answer 5

Part of the tyre that comes into contact with the road surface.
Protects the carcass and provides high grip, durability and manoeuvrability

Question 6

Steel Belts

Answer 6

Provides stiffness to the tread and protects the carcass

Question 7

Spiral Layer

Answer 7

Provides high durability and manoeuvrability

Question 8

Sidewall

Answer 8

Most flexible part of the tyre
Protects the carcass and provides comfortable ride

Question 9

Shoulder

Answer 9

Thickest part of the tyre
Protects the carcass from shocks and damages

Question 10

Plycord

Answer 10

Main body of the tyre
Sustains inflation pressure
Endures load and road shocks

Question 11

Bead Filler

Answer 11

This provides high durability & manoeuvrability

Question 12

Bead Wires

Answer 12

Holds the tyre on the rim

Question 13

Chafer

Answer 13

Protects the plycord at teh bead area from the heat generation of the abrasion between the bead and rim flange

Question 14

Camber

Answer 14

Angle of the axis of the wheel relative to the ground

Question 15

Castor

Answer 15

Angle of the wheel as seen from the side of the vehicle

Question 16

Roll Centre

Answer 16

The point in the transverse vertical plane through any pair of wheel centers at which lateral forces may be applied to the sprung mass without producing suspension roll
The roll centre is important as the distance from the roll centre to the vehicle centre of mass (gravity) results in a rolling moment when a cornering force is present

Question 17

Roll centre by drawn calculation

Answer 17

Extend lines of struts to the point where they meet. Then draw a line from the point at which the tyre meets the road to the point just found
The roll centre is on this line where it meets the vehicle centre line

Question 18

Ackerman Angles

Answer 18

Varies the steering angle based on the radius of the curve. Inside wheel has a greater angle than the ouside wheel

Question 19

Ackerman Usage

Answer 19

Ackerman is used on road vehicles. Racing cars may suit parallel or reverse Ackerman

Question 20

Coefficient of friction

Answer 20

In dry conditions - 1.0 - 1.1
In wet conditions - 0.6 - 0.7