Run-Flat-Tyres

Run Flat Tyres- How are they different from the ordinary tyres?


Run Flat Tyres Explained:

Run Flat Tyres: As the name suggests, these are the tyres which are capable of running even when flat i.e. in the punctured condition. These tyres are so designed that they allow the vehicle to cover the certain distance at reduced speed without compromising much on the stability.

So, the vehicle could travel either to the destination or to the service station nearby to change the tyre. The main aim behind inventing Run Flat Tyres is to eliminate as far as possible, the need to replace the punctured tyre by the roadside.



Construction of Run Flat Tyres:

The ability to run even when there is no air inside is bestowed upon the RFTs by their constructional specialities. As seen in the diagram below, RFTs have very strong sidewall reinforcement which bears the vehicle load in the absence of air. They also have special lateral reinforcements that provide additional strength to cope with the load.

Ordinary vs Run Flat Tyres (Courtesy: Bridgestone)
Ordinary vs Run Flat Tyres (Courtesy: Bridgestone)

 

Furthermore, high-grade heat-resistant rubber takes care of the additional heat built up arising in such situations. Depending upon the vehicle and tyre type, the RFTs can cover a distance from 80 km to 320 km in punctured condition. And generally, the recommended speed limit in such conditions is 80kmph.

Identification of Run Flat Tyres:

Visually there is hardly any difference between an ordinary tyre and a Run Flat Tyre. So, various tyre manufacturers have developed their own naming methodology to denote RFTs. Thus, with the help of a specific code in tyre nomenclature, RFTs could be identified easily.

Sr.No.



Name of Tyre Manufacturer

Identification Code

1

Bridgestone

RFT

2

Continental

SSR

3

Goodyear

RunOnFlat / EMT

4

Michelin

ZP

Advantages of Run Flat Tyres:

  1. Improved safety: As RFTs can continue running in the punctured condition, they eliminate the need to wait by the roadside to change the tyre thereby improving safety because such a halt can be dangerous sometimes.
  2. Helps to maintain vehicle control: Even if tyre bursts at high speeds, still vehicle doesn’t go out of control because of the RFTs. They ensure to restore the maximum vehicle stability in such conditions.
  3. Improved luggage space: As there is no need to carry a spare wheel, the space that would otherwise be utilized to store a spare wheel can be used as an additional storage space for luggage.

Applications of Run Flat Tyres:

In very early days, only the military vehicles made use of these tyres. Then, manufacturers employed RFTs on the specially designed safety vehicles such as armor proof vehicles that the elites like presidents of various countries, business people etc used. Nowadays, vehicle manufacturers offer them as a standard safety feature on high-end and luxury vehicles as well.

See Run Flat Tyres in action:

For more information, please click here.

Read more: Can a Tyre change its chape?>>

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