20p Tyre Tread Test

Joe_Horner

ChumLee wrote: »

Reckless in what respect? Not reckless in securing a conviction for corporate manslaughter.

Reckless in specifying that the tyres must be used beyond the point where safety is drastically reduced in order to cut costs.

The point of the 3mm recommendation is that there's a turning point in the stopping distance around that level. Before that the increase is gradual with wear, after that the increase becomes much faster.

If that documented fact translated into a corresponding increase in accidents (ie: a clear and identifiable effect on safety) with tyres below that level then insisting that they're used well past that point in order to save money would show a reckless disregard for the safety of the drivers and the public.

jase1

I find some of the part-worn brigade rather amusing on this subject. They'll assert that cheap tyres are dangerous, then buy part-worns at 3mm in some cases.

Most of the cheap tyres are nowhere near as bad as the very worst (which they use as 'evidence' that all cheap tyres are rubbish), and will, when new, stop far more sharply in the wet than a premium tyre with <3mm left on it.

Still it's their choice I suppose.

As for imperial measures, we're still arguing the toss over that? Jeez, anyone below the age of 50 who doesn't understand metric needs to go back to infant school.

ChumLee

Joe_Horner wrote: »

Reckless in specifying that the tyres must be used beyond the point where safety is drastically reduced in order to cut costs.

The point of the 3mm recommendation is that there's a turning point in the stopping distance around that level. Before that the increase is gradual with wear, after that the increase becomes much faster.

If that documented fact translated into a corresponding increase in accidents (ie: a clear and identifiable effect on safety) with tyres below that level then insisting that they're used well past that point in order to save money would show a reckless disregard for the safety of the drivers and the public.

And there is the issue, if. Does it translate or not?

anotherbaldrick

It's not only that grip drops off progressively steeply as the tyre wears but also the wear rate hits an upward curve as you get to the last few mm and the tread flexes less. The effect is that the dregs of the tread can disappear in a very short space of time. Therefore the gain by hanging on till you get down to the legal minimum is small, perhaps even only a few weeks motoring. Certainly no big deal and not worth risking embedding yourself in a HGV for.

Joe_Horner

ChumLee wrote: »

And there is the issue, if. Does it translate or not?

No it doesn't, much though the "what price sayftee / won't somebody think of the children" brigade would like to disagree. Which was kind of my point :beer:

onomatopoeia99

ChumLee wrote: »

Imperial was still being taught in mid to late 70s in England.

Not in my school. I rememeber a lesson when I was 8 or 9 (so around 1978) where the teacher asked us if we knew how many inches in a foot. Similarly feet in a yard, pounds in a stone and so on.

I knew them all, the other 30 kids (yeah, even in the halcyon days of yore, class sizes were over 30) didn't know any of them, and apart from that one lesson they were never mentioned.

Iceweasel

onomatopoeia99 wrote: »

Not in my school. I rememeber a lesson when I was 8 or 9 (so around 1978) where the teacher asked us if we knew how many inches in a foot. Similarly feet in a yard, pounds in a stone and so on.

I knew them all, the other 30 kids (yeah, even in the halcyon days of yore, class sizes were over 30) didn't know any of them, and apart from that one lesson they were never mentioned.

As a teacher I asked the question of a class of 12 year olds back in 2000 or so if they knew big a yard was.

One of them said it could be any size depending on how big a back garden you had.

Ah well - let's have a Yard Sale of everything we have imported from the US of A.

English is a living evolving language -innit?

Minrich

anotherbaldrick wrote: »

It's not only that grip drops off progressively steeply as the tyre wears but also the wear rate hits an upward curve as you get to the last few mm and the tread flexes less. The effect is that the dregs of the tread can disappear in a very short space of time. Therefore the gain by hanging on till you get down to the legal minimum is small, perhaps even only a few weeks motoring. Certainly no big deal and not worth risking embedding yourself in a HGV for.

Where do you get that gem from ?

robatwork

sillygoose wrote: »

Not me of course :whistle: but I wouldn't be surprised if the odd driver near the 2mm cutoff level finds a deserted lay-by some night and does a few burn-out and emergency stops to make sure they are low enough to qualify for a change next day...

Not tyres but you've just reminded me of the company car drivers in the 90s who would suddenly plan driving holidays to Scotland come the end of the tax year to get their mileage up above 18k.

anotherbaldrick

Minrich wrote: »

Where do you get that gem from ?

50 years of motoring experience .