Volkswagen ID.3: Wheels, tyres. axle align. Evaluating tyres

Volkswagen ID.3 (E11, E12) 2020-2024 Service Manual / Running gear / Wheels and Tyres Guide – General Information / Wheels, tyres. axle align. Evaluating tyres

Flat spots caused by storage and handling
Undulations
Flat spots caused by hard braking
Swellings in the tyre sidewall
Tyre damage due to insufficient tyre pressure
Checking tyres
Damage caused when fitting

Flat spots caused by storage and handling

What is a flat spot?

The terms flat area and flats are also used for the term flat spot.

Flat spots caused by storage or handling also cause vibration in the same way as incorrectly balanced wheels do. It is important that flat spots on the tread are identified as such.

Flat spots caused by storage or handling cannot be balanced and they can reoccur at any time due to various circumstances. Flat spots caused by storage or handling can be eliminated without complicated special tools. This does not apply to flat spots caused by hard braking → Chapter.

Note

Flat spots caused by hard braking cannot be repaired. Such tyres must be renewed.

Reasons for flat spots caused by storage or handling:

♦ The vehicle has been left standing in one place without being moved for several weeks.

♦ The tyre pressure is too low.

♦ The vehicle was placed in a paint shop drying booth after being painted.

♦ The vehicle was parked with warm tyres in a cool garage or similar for a long period of time. In this case, a standing flat spot may even occur overnight.

– Eliminate flat spots caused by storage or handling → Chapter.

Undulations

Radial depressions are slight concavities in the tyre sidewall.

They run from the bead towards the shoulder of the tyre. These parts appear in the figure → Fig..

The cause is the accumulation of material at the joints of the tyre components.

Radial depressions do not influence:

♦ Safety

♦ Service life

♦ Handling

♦ Other characteristics of the tyre

Undulations are visible to varying extents. It is not necessary to inspect the tyre or remove it from the rim.

What causes undulations?

Modern steel-belted tyres are constructed with single-ply side walls to save weight.

The sidewall components consist of long strips before they are joined together to form a tyre. They must overlap at the joints. Consequently, slight irregularities or waves are created in the area of the overlapping parts. The overlaps are easier to see from the outside due to the single-ply construction.

Flat spots caused by hard braking

♦ This type of flat spots may be caused by hard braking on a rough surface such as a tarmac road.

♦ During this type of braking manoeuvre only a certain area of the tyre is abraded accordingly and therefore causes an imbalance.

♦ Consequently, a flat spot caused by hard braking results in vibration in the vehicle, deteriorated vehicle handling and increased noise.

♦ In most cases a wheel with this kind of tyre tends to lock again in the area with the larger contact surface between road and tyre even at lower braking forces and therefore cause even higher vibration.

♦ If the flat spot caused by hard braking is not too significant, the vibrations may stop after the tyre has been worn all-round accordingly.

NOTICE

Flat spots with irreparable damage to the tyre caused by extreme braking.

– Renew the tyre.

Swellings in the tyre sidewall

A swelling in the sidewall of the tyre indicates that the substructure of the carcass has been damaged.

Typical causes for such damage include, for example, driving over kerbs at a sharp angle.

Pinching the tyre in this way can damage the carcass.

The substructure of the tyre is stretched so far that individual fibres in the carcass may be broken.

The extent of the damage depends on the speed of impact, the angle of impact, the tyre pressure, the axle load and the type of obstacle.

Pinch marks on tyre sidewall -arrows-

Note

♦ Driving over kerbs should be avoided.

♦ If you cannot avoid driving over a kerb, you should do so very slowly and as square-on as possible.

Interior view of a tyre with a punctured carcass

Due to a severe impact, the carcass was pinched on the wheel rim flange and is ruptured in the contact area.

Damage inside tyre due to impact injury (double rupture)

Double rupture -arrows- caused by pinching when a kerb was driven over. Often not detectable from outside.

Tyre damage due to insufficient tyre pressure

The most common causes for tyre failure are minor external damage, a defective valve or a leaking rim due to corrosion or damage.

Separation of carcass and rubber

Excessive heating due to driving with substantially insufficient tyre pressure led to overheating and subsequent separation of the carcass from the rubber material -arrows-.

The tyre shown here was periodically driven with an inflation pressure which was insufficient for the load. Typical evidence for this is the circumferential scuffing along the bead caused by the wheel flange and also the discolouration. Small, furrowed creases are visible along the inside of the sidewall.

When the tyre rolls, strong shear forces develop between the layers of steel cord, especially at the ends of the belts.

Tyres with wide, circumferential furrows near the bead

Wide, circumferential furrows near the bead -arrows- indicate that the tyre was driven with insufficient pressure.

Driving a vehicle with insufficient tyre pressure or ignoring or not recognising tyre damage can have serious consequences.

The tyre can no longer withstand the forces which develop when the vehicle is driven.

The defects mentioned above severely restrict the function of the tyre. The rubber compounds separate, which results in the partial separation of tyre components or even its complete destruction.

Checking tyres

As tyre damage can have serious consequences, you and the driver should regularly check the tyres to identify any problems at an early stage.

Damaged tyres cannot withstand driving conditions such as high speed, long distances, sporty driving, and so on.

Damage can be caused in a number of ways:

♦ Driving with insufficient tyre pressure

♦ Assembly error when tyres were fitted on rims

♦ Damage by embedding objects

♦ Ageing

♦ Improper storage

Note

Whenever a safety risk cannot be ruled out, the tyre must be renewed.

When checking a tyre, look out especially for the following criteria:

♦ Surface erosion or ripples on the inner side (inflation pressure was too low or not sufficient for the load)

♦ Loose rubber or loose radial threads

♦ Separated or deformed bead core

♦ Damage to tyre bead with cord ply visible

Damage caused when fitting

Bead core broken during tyre inflation.

Modern radial tyres for passenger cars are mounted only on safety rims. Safety rims have a hump -1- running along the bead seat.

1 - Hump

2 - Inner rim shoulder

3 - Wheel rim

4 - Wheel disc

5 - Outer rim shoulder

The hump prevents the tyre from being pressed out of the rim shoulder when travelling with insufficient tyre pressure.

When the tyre is inflated, the bead of the tyre may not slip completely over the outer rim hump.

In this case, there is a danger of the bead core becoming overstretched if the tyre pressure is too high. The steel wires would then rupture partially or completely. A broken bead core cannot be detected from the outside.

CAUTION