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Runflat Tyres

At Jacksons MOT Centre we always have a large selection of quality Runflat tyres for every season available for either home delivery or fitting at our workshop. Please have a look at our tyre search section. You will be able to find the right Runflat tyre for your vehicle following our easy instructions.

For any questions you might have or to make a decision which tyres to buy, please contact us - or simply come to see us.

Here we have also put some information together regarding Runflat tyres you might find interesting and helpful.

Runflat tyres are tyres with emergency running characteristics.  With the Runflat technology, carrying a spare is no longer necessary.

From a purely statistical point of view, every driver in the UK is experiencing a tyre puncture every five to seven years, after 65,000 to 100,000 miles of running.  The incidents are usually very unpleasant for the individual: a nocturnal stop on a small country road or busy motorway, perhaps even in the rain or cold, a spare wheel, which also ran out of air, lack of practice and skill during tyre change.

Since the causes of tyre punctures- nails, glass shards or damaged road surfaces - can never be completely ruled out, the solution had to lie in the tyre itself.

At the BMW Group for example, tyres are used, which continue to run for many miles despite the loss of air pressure - the tyres with emergency running characteristics (Runflat System Component RSC).

The tyres with emergency running properties, the so called Runflat Tyre (RFT) - is, so to speak, normal and spare wheel in one.  The layman only distinguishes the difference between a regular and a Runflat tyre by its specific inscription on the tyre sidewall.  The Runflat technology allows you to continue the journey even if there is excessive air pressure loss over a certain distance.

An additional rubber element inside the self-supporting tyre prevents the damaged tyre from falling in the case of pressure loss.  Also convincing is the far greater stability of the Runflat tyre in the event of sudden pressure loss at a high driving speed, such as on the motorway and especially in curves.

In the event of excessive pressure loss, the tyre failure indicator (RPA) will emit a visual signal in the cockpit of the car.  The driver is requested to reduce the driving speed within the specified range (maximum 50mph).  Runflat's residual plate lengths vary according to vehicle type and external factors.  At a correspondingly adapted speed, the next service station or the nearest garage can be reached with Runflat tyres despite tyre damage. Thus the vehicle is not a dangerous obstacle in the dense road traffic, both the flowing traffic as well as the inmates of the vehicle are protected.

A tyre with many names.  Behind the names and abbreviations RunflatTyre (RFT) and Runflat System Component (RSC) conceals itself as the same phenomenon:

The Self Supporting Tyre (SST), a self-supporting tyre with emergency running characteristics.  A worldwide valid tyre standard for Runflat and thus a separate tyre designation is not yet available.  The abbreviation RFT emphasizes the tyre as a single element.

RSC understands the self-supporting tyre as a component (runflat system component) in a connected whole system of tyre, rim and early warning system.

The effect of the self-supporting tyre is achieved by a "special equipment" in the tyre interior:

On the inner walls of the tyre there are additional rubber inserts on both sides.  The specific temperature-resistant rubber mixture remains stable even in extreme cases when the tyres are used in the event of a breakdown.  The deformation of the tyres by high load - e.g.  During cornering and overheating is largely prevented.

At the moment, RSC tyres are more nuanced compared to normal tyres - but this subtle difference is only noticed by sensitized drivers on uneven ground.

How far you can drive after a tyre damage and air pressure loss is dependent on the respective car type, the load of the car, the residual pressure in the tyre as well as the driving speed.  At a tyre pressure of 0 bar, the speed must ideally be reduced to 50 mph, and a further 90 miles minimum can be driven.  With a residual pressure of approx. 0.3-0.5 bar still present in the majority of cases, considerably larger emergency run distances can be achieved.

In the trial, second-generation RSCs with RPA warning were used to achieve run distances of 1200 miles and more (with a standard tyre less than five kilometers).

RSC achieves its effectiveness only in combination with two other components:

An early warning system in the form of a tyre pressure indicator (RPA) or optionally a tyre pressure control system (RDC).

And a special shaped rim type, the so-called Extended Hump rim.

Only through the interaction of these three elements does the spare wheel become unnecessary.  RSC is therefore only used in a standard package tyre, rim and early warning system.

Runflat Indicator;

An electronic tyre breakdown indicator (RPA) replaces the sight of the flat tyre with an optical warning signal in the dashboard.  The RPA concludes a loss of air pressure due to increased rotational speeds of the tyres running under reduced pressure: if air escapes, the tyre circumference and rolling radius change.  The rotational speed of the wheel is inevitably increased.  With the help of sensors the rotational speeds of the tyres are continuously checked.  RPA compares the diagonally associated tyres and their average speed.  The basic data of the tyres serving as the reference point for data matching are determined during the initialization phase of the RPA.  If the RPA results in a critical deviation, a message appears in the dashboard.  Already at a pressure drop of about five tenths (about 30 percent) below the normal pressure, the driver is warned.  The ISO-standardized warning sign represents a tyre cross-section with exclamation marks.

The warning threshold for the tyre air pressure monitoring is now available at RPA.  It is not as low as the comparable high-tech early warning system RDC / tyre pressure control.  In contrast to RPA, RDC does not determine tyre damage due to changes in the rotational speed of the tyres but due to pressure and temperature changes.  In addition, RDC records the smallest filling pressure losses in the tenth of a bar range both in the barrel and in the stand.  Wheel pressure and temperature are measured in each tyre by wheel electronics.