ContentsTyre-functions & Properties.Tyre-Types Types of carcass(Tread)Comparison of radial & bias-ply tyresTyre materials & Considerations in tread designTyre designation & Factors affecting tyre lifeTyre trouble shooting & Tyre manufacturing
Tyre and its functionsTyre is a rubber member which gives the cushion to the automobile. It consists of outer cover i.e. tyre proper and tube inside.The tyre-tube assembly is mounted over the wheel rim and air inside the tube carries entire load and provides cushion.
Comparison of radial and bias-ply tyresAdvantages of radial ply tyres:- The side walls can be bend readily ,its shock absorbing capacity is 25% more than bias ply or cross ply. The breaker strips of radial tyres act independently of the wall plies unlike in cross ply where there is no breaker strip. Lower rolling resistance and hysteresis loss leads to less fuel consumption.
Longer tread life because of less heat build in tyre. Breaking efficiency on wet roads is better because of greater sidewall flexibility and tread stiffness. Smaller slip angles and higher cornering power which results in Better steering characteristics. While taking turns it has less tendency to distort and lift off the road from one side. Larger resistance to punctures ,cuts and impacts in the tread area.
Tyre materialsFor carcass:- At the time of second world war, staple cotton was the tyre carcass material and it was replaced with rayon. Then nylon was introduced which is stronger, more elastic and cooler running than rayon. Then terylene was introduced.
For cords of stabilizer belts:- Rayon ,Terylene ,glass fibre or steel.Rubber :- Rubber used in tyres is blend of natural and synthetic rubbers to which various chemicals are added to obtain desired properties like wear resistance ,reduced hysteresis, less internal friction.
Considerations in tread design Grip Noise wear
Factors affecting tyre life Inflation Vehicle maintenance Manner of driving Miscellaneous factors
Tyre trouble shooting Side wear of tyres One side wear of tyres Centre wear of tyre tread Uneven tyre wear Uniform rapid wear Rapid wear with feathered edges on the tread Tread cracking Tread or ply separation Loss of tyre pressure Radial tyre lead Radial tyre waddle