Run-flat tyres
In recent years the leading tyre makers have been racing each other to advertise their latest achievement: tyres that are not afraid of punctures. These tyres are called run-flat tyres. Given a whole range of factors, though, this advertising looks more like a false start in a race - the market is not yet ready for a mass takeover by thick-profile tyres.
“Puncture-proof” run-flat tyres
Not so long ago, tyres began appearing on the tyre market that, according to their makers, do away completely with the need for a car’s spare wheel. Is that really true?
In general, the idea of a tyre that is not afraid of punctures has occupied inventors’ imaginations ever since the pneumatic tyre itself was invented (a tyre whose shape is held by the pressure of the air pumped into it), as a concept. It is worth noting that such tyres were invented by Robert Thomson as far back as 1846.
Over the last few decades countless different concepts of a “puncture-proof” tyre have been tried, from a solid construction (which needs no air at all) to filling tyres with a special elastic sealant able to automatically “seal up” small punctures. In the end, though, every tyre maker arrived at the same conclusion: the best way to develop the idea is to reinforce the tyre’s sidewalls - the so-called self-supporting tyre.
It is precisely these tyres that lose comparatively little in performance and, in some cases, really are able to do away with the need for a spare wheel as such. That said, this is only relevant in certain situations for now, and running modern run-flat tyres still comes with a number of nuances that any motorist thinking about buying this novelty absolutely needs to understand.
Articles in this sectionIn reading order.
- What are run-flat tyres?Tyres made using the technology called RunFlat have sidewalls strong and stiff enough to carry the car’s weight even once the pressure inside the tyre has dropped to match the outside air.137 words
- Run-flat tyres: pressure monitoringIf a car is not fitted with a tyre pressure monitoring system, using run-flat tyres creates a real threat, at best to your wallet and at worst to your life, and is therefore categorically not…138 words
- Run-flat tyres: repairabilityNo fitter at any tyre centre can restore the stiffness of these sidewalls once they have been cut, so with a sidewall puncture (cut) a tyre like this is definitely headed for the scrap heap.86 words
- Run-flat tyres: strengthWhatever the makers claim, it is quite obvious that once the pressure in a tyre drops, the whole weight of the car ends up resting on the tyres’ sidewalls, so the load on them rises by orders of…121 words
- Run-flat tyres: extra weightIt is obvious that the extra sidewall stiffness is achieved, among other things, by thickening the profile. More rubber compound means more tyre weight.125 words
- Run-flat tyres: characteristics and stiffnessRun-flat tyres can only be used on cars designed for them. The question of a suspension being universal enough (that is, adapting to different sidewall stiffnesses) essentially calls for separate…137 words
- Run-flat tyres: road infrastructureThe problem is that Ukraine’s road infrastructure is not yet geared up, as a matter of principle, for technology like this.113 words
- Run-flat tyres: the tyre-fitting problemA substantially stiffer sidewall makes fitting the tyre to the wheel harder, calling for the right equipment. At a roadside tyre-repair shop (and, in fact, at most city tyre fitters too) they are…104 words
- Run-flat tyres: conclusionsOn closer inspection, “puncture-proof” tyres are simply a nice myth for the vast majority of motorists.88 words