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Codes and designations on tyres with run-flat capability (PAX) > < Tyres with run-flat capability (PAX)

A3 Mk1

Construction of tyres with run-flat capability (PAX)
Construction of tyres with run-flat capability (PAX)
Run-flat tyres (PAX) are specially developed tyres that differ from conventional tyres as follows:
PAX tyre with support ring
–  -I- PAX tyre with air
   
–  -II- PAX tyre without air
–  The tyre is anchored on a special rim which prevents the tyre from sliding off when air is lost. The support ring is made of rubber and maintains stability in the event of a pressure drop.
t  The inner and outer bead diameters differ in size. This makes it possible to add a support ring inside the tyre.
t  The tyre is secured differently to the rim.
t  This allows the tyre height to be greatly reduced. This was made possible by the reduced bead area due the special connection between the tyre and rim.
t  The tyre beads are formed such that they engage in the rim seat. Therefore, the tyre remains firmly secured to the wheel/rim even when there has been a loss of inflation pressure.
  A44-10070
Construction of the bead area for a standard tyre
1 - Wheel flange
2 - Inner plies
3 - Bead core
  A44-10041
Construction of bead zone on tyres with run-flat capability (PAX)
1 - Loop
2 - Inner plies
3 - Bead core
4 - Wheel flange
  A44-10042
Seating of tyres with run-flat capability (PAX)
Due to the construction of the tyre, it remains firmly attached to the wheel in all driving situations.
A wedged-shaped component of the tyre is thereby pressed between the bead core and rim by the load. This occurs regardless of the tyre pressure.
  A44-10043
Dimensions of tyres with run-flat capability (PAX)
As compared to standard tyres, run-flat tyres (PAX) have different dimensions and designations.
Run-flat tyres (PAX) can therefore only be fitted to special wheels designed for the PAX system.
1 - Width in millimetres: tyre width from sidewall to sidewall on the standard rim (corresponds to the width dimension on standard tyres)
2 - Outer diameter in millimetres: maximum diameter of the new tyre
3 - Nominal diameter in millimetres on standardised rim seat
4 - Small bead diameter in millimetres: outer rim seat
5 - Larger bead diameter in millimetres: inner rim seat
  A44-10044

Codes and designations on tyres with run-flat capability (PAX) > < Tyres with run-flat capability (PAX)