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Run flat tyres (tyres with emergency running characteristics) > < Increase in temperature of an underinflated tyre

Leon Mk2

Tyre damage resulting from mounting errors
Tyre damage resulting from mounting errors
Bead broken as tyre is inflated
   
Modern radial vehicle tyres are exclusively fitted on safety rims, these have a perimeter ridge on the shoulders -1-.
1 - Hump (double hump H 2, high double hump EH2)
2 - Wheel rim contour:
3 - Interior shoulder of wheel rim (for example, oblique shoulder rims)
4 - Wheel rim
5 - Wheel rim plate:
6 - Lower throat
7 - Exterior shoulder of wheel rim (for example, oblique shoulder rims)
This ridge prevents the tyre bead from being flattened by the wheel rim shoulders when driving with underinflated tyres.
When the tyre is inflated, the bead may be caught on the narrow shoulder rim, on the ridge, on part of the perimeter.
In this case, there is a risk of forcing the tyre bead in the event of overinflation, and breaking the steel cables either partially or totally. Generally, breaks in the bead can not be perceived from the exterior.
Special features on tyres with emergency running characteristics
Tyres with emergency running characteristics (reinforced side walls) require rims with extended double hump (extended double hump EH2) → Chapter. The extended double hump prevents the deflated tyre from separating from the rim when flat.
  Note
To prevent damage during mounting it is absolutely necessary to observe the instructions for mounting tyre with emergency running characteristics in the guidelines → Running rear, axles, steering; Rep. gr.44.
  WARNING
t  Tyres with damaged bead do not fit safely onto the wheel rim. These tyres are dangerous.
t  There is also a risk that the broken bead will be detached if the vehicle continues to be driven, and the tyre may break suddenly. If there is a break in the bead when the tyre is inflated during assembly, this will also destroy the tyre carcass.
  N44-10214
Tyres with split bead and carcass
The figure shows a split bead and broken carcass as a result of excess tension when mounting the tyre.
Damage to the bead as a result of faulty or incorrect assembly of the tyre on the assembly machine
The following faults in the tyre assembly may result in serious damage to the tyre:
t  When the lower bead is not in contact or only partially in contact with the bottom channel when inserting the upper bead into the machine → Anchor
t  When the mounting head is adjusted incorrectly
t  when the tap of the edge of the mounting roller is incorrect
t  when the guide rollers are worn or have edges
  N44-10238
Tyres with damage to the bead
As a result of the above-mentioned circumstances, the floor of the bead may divide up under excess strain along the perimeter and/or be flattened to the bead strands.
  E44-10120
Often there are signs of incrustation and the exit of the guide roller in the region of the damage.
  Note
As a general rule, both tyre beads and the wheel rim shoulders should be lubricated with a product to ease movement.
If damage produced during assembly is not taken into account, there is a risk of faulty tyres at a later stage.
NOTE:
t  Never without assembly paste
t  Step pressure never over 3 bars
t  Seat pressure never over 4 bars
t  Finally reduce to specified tyre pressure
  E44-10121

Run flat tyres (tyres with emergency running characteristics) > < Increase in temperature of an underinflated tyre