3. Directional Tyres
Run Flat tyres
There is an increasing trend in the OE (Original Equipment) market with regards to the fitment of run-flat tyres. There are three variations on this theme of tyre: Self Supporting, Self Sealing and auxiliary supported tyres. These tyres are available in the usual tread patterns of a manufacturers range(s) and are denoted with the letters such as SSR (Self Supporting Run-flat for Continental, RFT (Run-flat technology for Bridgestone, DSST (Dunlop Self Supporting Tyre for Dunlop.
These tyres are constructed with extra layers of rubber and heat resistant cord within the sidewalls to prevent folding and creasing if the tyre loses inflation pressure. There are specific EH2 rims that are used for this particular application. these tyres can also be used in conjunction with standard rims providing the TPMS (tyre pressure monitoring system) and its sensors are present.
Self Sealing tyres
These tyres incorporate an extra layer on the inner liner that seals itself in the event of a small penetration. These are treated in the same manner as standard tyres.
Auxiliary Support Tyres
These tyres utilise an additional component known as a support ring. The ring itself, as the name implies, supports the tyre and vehicle when the tyre loses inflation pressure. Specific wheels and tyres need to be fitted to the vehicle for this particular system to be used.