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Talking Tyres • 31
casualty after encountering an errant rock on a gravel road. As no replacement
tyre (naturally, fitted to the appropriate and costly rim) was immediately
available, the 800-grand X6 had to endure the ignominy of travelling back to
Pretoria on a flat-bed. Imagine the fury if you were the owner …
And it’s not just the ultra-exclusive sizes that are problem. I contacted a
couple of tyre dealers around the country to determine the availability of
various sizes of run-flats. Several dealers indicated that they didn’t carry stock
of run-flats at all. Some had a few of the more ‘popular’ sizes, but would
have to call on regional or national distribution centres for the most part.
Therefore, expect a delay ranging from one hour, or even one to two days
to get your rubber – and that’s assuming there are any suitable tyres in the
country which, shockingly, isn’t always the case.
The main reasons the tyre dealers cited for the lack of run-flat stock were
the huge variety of sizes and tread patterns, the very low demand and the
massive cost. One multi-brand tyre dealer suggested an outlay of R100 000
would be required just to carry a single set of run-flat tyres for each brand
he represents.
That cost also relates to the consumer. Based on my brief survey, which
priced a total of 10 tyres from various brands and tyre dealers across the
country, run-flats are on average 35-percent more expensive than standard
replacement rubber – with a high of 65 % and an unusual low of 10 %.
Add in the additional expense of a mandatory tyre pressure monitoring
system (about R5 000) and that run-flat repairs are generally discouraged
(or very expensive to do, by specialists only), and the whole run-flat concept
becomes rather costly.
Run-flat repairs are
generally discouraged
which adds to the cost.
Fitment capability
and availability remain
a problem.
Factor in the huge complexity of the technology, with all the confusing jargon
and marketing-driven acronyms: full marks for Yokohama simply referring to
Run Flat, while Bridgestone uses RFT, Dunlop DSST, Goodyear EMT and ROF,
Michelin ZP and Continental SSR, while BMW has its very own RSC mark.
Plus there’s unresolved issues surrounding the additional unsprung mass of
the tyre necessitated by the extensive sidewall strengthening. Logically, this
makes it both less efficient due to increased rotational mass, and reduces the
pliancy and comfort of the tyre – although tyre and car manufacturers are
making ongoing progress in these areas.
All considered, if I lived in Europe, run-flats would be a no-brainer. But I don’t,
so they’re not.
Colin Mileman is a freelance motoring journalist, photographer
and advanced driving specialist with over 13 years of experience
in this field. As a former editor of Topcar and Topbike magazines,
he’s as enthusiastic about cars and bikes as they come, and has
extensive knowledge of all motoring-related matters, including
the topic of tyres, having run the annual and highly regarded
Topcar tyre tests for several years.