Tyres

As you will have noticed if you live in Hampshire, it’s been snowing and icy for the last week. Local traffic has not coped well.

Our house is at an end of a long windy dead-end estate road; there are maybe 10 more houses further along than ours. This means that the road doesn’t get gritted, and there isn’t enough passing traffic to take the snow and ice away. This makes driving from our house hazardous in sub-zero temperatures, to say the least.

A couple of weeks ago when I got the MOT for my car they told me that I was down to 3mm of tread on the rear tyres and about 5mm on the front tyres. So replacing the rear tyres was on my todo list anyway; the snow and ice merely made it urgent. Attempting to get to work on Monday we were doing about 20mph when a 4×4 pulled out of a side road about 60 metres ahead and set off at about 8mph. I’d lifted off the throttle when he appeared and when we closed to about 20m I got on the brakes. Then stood on them. Then got rather worried. We were probably 10cm away when the ABS & EBD vs Snow & Ice battle was finally resolved in favour of us not crashing.

OK, so I was going too fast for the conditions. In my defence, the car felt fine up to that point – steering, acceleration, etc all felt normal. ESP and Traction Control (with ect snow mode engaged) clearly do their job well, but they did give me a false sense of security.

Part of the blame also has to be accounted to the tyres, or rather the tyre distributors. In other countries, you can get three sorts of tyres:

  • Summer tyres
  • Winter tyres
  • All season tyres

In the UK, almost all the tyres I could find in the size to fit my rear wheels are classified as Summer tyres; in fact the only all season tyre I could find in 245/45/17 was the Falken ZIEX ZE-912. Snappy though that name is, it seemed the only option if I wanted something which will actually work in winter. I now have a set of 4 bolted to my car; they seem to work well so far, although 2 miles isn’t much of a test. They also have quite good reviews on various Lexus IS forums. I tried them on the way back from the fitters on some extant ice in our estate and they did seem significantly better: of course anything with 8-9mm tread would be better than what I had so again I don’t really know anything.

And now, after over 400 words, we arrive at what passes for the point of this blog. The cross-country tyres I used to use on my XC bike were fitted in opposite rotational directions front and back so that the tread at the back was optimally arranged to give you acceleration and the tread at the front was optimally set-up for retardation. Why aren’t car tyres like that, at least for rear-wheel-drive cars?

One Response to “Tyres”

  1. Alexis

    Mytyres list 38 tyres in that dimension that they class as ‘winter’ tyres, and plenty of them certainly have wintery names, such as Vredestein Wintrac xtreme, Pirelli W 240 Sottozero, and so on. Obviously that may not be feasible if you need them instantly, but I was certainly under the impression that winter tyres were now quite commonly available, even in low-profile performance-sized tyres.

    An Elise at a airfield sprint day recently reportedly ran rings around several considerably quicker cars recently on a cold, wet day due to being fitted with winter tyres so they are definitely a wise investment.

    Another option which is quite common in Europe is to fit smaller wheels to the car in the winter with winter tyres on them. This gives the advantage of cheaper tyres, better snow performance (as the narrower tyre will dig in deeper than a wide tyre) and the ability to swap to summer tyres easily at home. Obviously some care needs to be taken to find wheels that will clear the brake calipers.

    As for tyre rotational direction, I was under the impression that typically rotationally-dependant tyres were designed to remove water from the tread area efficiently allowing the tyre to maintain contact with the road, rather than to improve actual road-to-tyre grip. As such I can’t see that in most situations a tyre on the front wheels that is mounted in the opposite direction would aid retardation in anything other than reverse.

    With respect to the bike tyres and knowing (as you know) very little about cycling, those tyres linked seem to be designed for off-road terrain. I can see a valid benefit in altering the rotational direction on a surface that is deformed by the tyre, such as mud. I suppose the same could be said for snow with a car tyre, but I can’t think of many other situations a non-offroad vehicle would benefit from this. It would be interesting to see if proper studded snow tyres do have this characteristic, but I wouldn’t necessarily expect to see it on a standard winter road tyre.

    Reply

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