Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 3rd Term
Week: 10
Age: 15 years
Duration: 45 minutes
Subject: Auto Mechanic Work
Curriculum Theme: Auto Mechanic Work
Previous Lesson: Rims Types, Sizes and Removal Tools.
Topic: TYRES – Functions, Sizes and Designation
Subject Matter: functions of tyres, tyre sizes, tyre designation, tube tyres, tubeless tyres, differences between tube and tubeless tyres

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Define a tyre.
State at least three functions of tyres.
Explain how tyre sizes and designations are read.
Describe tube tyres and tubeless tyres.
Differentiate between tube tyres and tubeless tyres.

Affective Domain:

Appreciate the importance of selecting the correct tyre size for a vehicle.
Value the role of tyres in vehicle safety and performance.

Psychomotor Domain:

Identify examples of tube and tubeless tyres.
Point out tyre designation markings on a tyre.

Discuss with peers the implications of using worn-out tyres.

Reference Materials

The following resources were used in planning this lesson:

Nigerian Senior Secondary Education Curriculum for Auto Mechanic Work.
State Unified Scheme of Work.
Auto Mechanic Work for Senior Secondary Schools, Book 1.

Instructional Materials

The teacher will teach this lesson with the aid of:

A tube tyre.
A tubeless tyre.
Charts showing different tyre sizes and designations.
Whiteboard and markers.
Lesson plan.

Rationale for the Lesson

This lesson helps pupils understand an important component of vehicles – tyres. Understanding tyre functions, sizes, and types enables pupils to make informed decisions about tyre maintenance and selection, which is important for vehicle safety and performance.

Prerequisite/Previous Knowledge

Pupils should have basic knowledge of vehicles and their main components.

Lesson Content/Board Summary

TYRES – Functions, Sizes and Designation

Definition of Tyre

A tyre is a ring-shaped component that fits around a wheel’s rim to transfer the vehicle’s load from the axle to the ground and provide traction while the vehicle moves.

Functions of Tyres

The functions of tyres include:

Supporting the weight of the vehicle.
Providing traction for acceleration and braking.
Absorbing road shocks for a comfortable ride.
Changing and maintaining the direction of travel.
Transmitting driving and braking forces to the road surface.

Tyre Sizes and Designation

Tyre designation is a code found on the sidewall of a tyre that indicates its size, type, and performance characteristics. An example is P205/55R16 91V.

Breakdown of an example (P205/55R16 91V):

P: Indicates the tyre is for Passenger vehicles.
205: Represents the tyre’s width in millimetres (205 mm).
55: Is the aspect ratio, meaning the height of the sidewall is 55% of the width.
R: Denotes Radial construction, the most common type.
16: Is the diameter of the wheel rim in inches (16 inches).
91: Is the load index, indicating the maximum weight the tyre can carry.
V: Is the speed rating, indicating the maximum safe speed for the tyre.

Types of Tyres

Tube Tyres

Tube tyres consist of an outer casing (tyre) and an inner tube that holds the compressed air. The inner tube is inflated and placed inside the tyre casing, which then fits onto the wheel rim.

Characteristics of tube tyres:

Requires an inner tube to hold air.
Often used in heavy-duty vehicles or off-road applications.
A puncture in the tube causes a sudden loss of air.

Tubeless Tyres

Tubeless tyres do not require an inner tube. They have a special lining on the inside of the tyre and a tight seal between the tyre bead and the wheel rim to hold the air directly.

Characteristics of tubeless tyres:

Does not require an inner tube.
Commonly used in modern passenger vehicles.
A puncture often results in a slow leak, allowing time for repair.

Differences between Tube and Tubeless Tyres

The key differences between tube and tubeless tyres are:

Inner Tube: Tube tyres use an inner tube, while tubeless tyres do not.
Air Retention: Tube tyres hold air in the inner tube; tubeless tyres hold air directly by sealing against the rim.
Puncture Behaviour: Tube tyres deflate quickly when punctured; tubeless tyres often deflate slowly.
Weight: Tubeless tyres are generally lighter due to the absence of an inner tube.
Heat Dissipation: Tubeless tyres dissipate heat better than tube tyres.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to identify the round, black components on a vehicle that enable it to move. The teacher then writes the topic “TYRES – Functions, Sizes and Designation” on the board.
Pupils’ Activity: Pupils respond by identifying tyres and copy the topic from the board.
Learning Point: Pupils are introduced to the topic and its relevance.

Step 2: Functions of Tyres

Time: 10 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains the definition of a tyre and discusses its various functions, writing key points on the board. The teacher uses a real tyre to point out parts related to its functions.
Pupils’ Activity: Pupils listen attentively, ask questions, and take notes on the functions of tyres.
Learning Point: Pupils understand what a tyre is and its importance in a vehicle.

Step 3: Tyre Sizes and Designation

Time: 10 minutes
Teaching Skill: Explanation/Illustration
Teacher’s Activity: The teacher explains how tyre sizes and designations are indicated on the sidewall of a tyre. Using a chart or a real tyre, the teacher demonstrates how to read and interpret the various codes (e.g., width, aspect ratio, rim diameter, load index, speed rating).
Pupils’ Activity: Pupils observe the markings on the tyre/chart, listen to the explanation, and ask questions for clarification.
Learning Point: Pupils learn to interpret tyre markings to understand tyre specifications.

Step 4: Types of Tyres – Tube Tyres

Time: 5 minutes
Teaching Skill: Description/Demonstration
Teacher’s Activity: The teacher introduces the concept of different tyre types, focusing first on tube tyres. The teacher displays a tube tyre and an inner tube, explaining its construction and how it holds air.
Pupils’ Activity: Pupils observe the tube tyre and inner tube, listening to the teacher’s explanation.
Learning Point: Pupils identify and understand the characteristics of tube tyres.

Step 5: Types of Tyres – Tubeless Tyres and Differences

Time: 5 minutes
Teaching Skill: Comparison/Explanation
Teacher’s Activity: The teacher displays a tubeless tyre and explains its construction, highlighting that it does not require an inner tube. The teacher then clearly explains the differences between tube and tubeless tyres, emphasizing advantages and disadvantages of each.
Pupils’ Activity: Pupils observe the tubeless tyre and compare it with the tube tyre, noting the differences.
Learning Point: Pupils can distinguish between tube and tubeless tyres and understand their respective features.

Step 6: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define a tyre.
Mention three functions of a tyre.
Explain what the “R” in a tyre designation like P205/55R16 means.
State two differences between a tube tyre and a tubeless tyre.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 7: Conclusion

Time: 5 minutes
Teaching Skill: Summarization/Assignment
Teacher’s Activity: The teacher summarizes the main points of the lesson, reiterating the functions, designation, and types of tyres. The teacher assigns homework: “Draw and label a tyre, indicating where the designation is found.”
Pupils’ Activity: Pupils listen to the summary and copy the homework assignment.
Learning Point: Pupils consolidate their learning and prepare for further study.

Lesson Keywords

Tyre – A rubber component fitted around a wheel rim to provide traction and support.
Tube tyre – A type of tyre that uses an inner tube to hold air.
Tubeless tyre – A type of tyre that holds air directly without an inner tube.
Tyre Designation – A code on the tyre sidewall indicating its size and characteristics.
Aspect Ratio – The ratio of the tyre’s sidewall height to its width.
Load Index – A numerical code indicating the maximum load a tyre can carry.
Speed Rating – An alphabetical code indicating the maximum safe speed for a tyre.

Differentiation

For pupils who are visual learners, the teacher will use charts and real examples of tyres to illustrate concepts. Kinesthetic learners will benefit from handling the different tyre types. Auditory learners will benefit from the teacher’s explanations and class discussions. Advanced learners can be encouraged to research specific tyre technologies (e.g., run-flat tyres), while struggling learners will receive additional guidance and simplified explanations.

Note for teachers using this lesson plan

Teachers should ensure that actual examples of tube and tubeless tyres are available for demonstration. Emphasize safety aspects related to correct tyre usage and maintenance. Encourage pupils to relate the lesson to real-life vehicle scenarios.