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Stretched tyres - an MOT failure? - Information from DVSA

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https://mattersoftesting.blog.gov.uk/stretched-tyres-an-mot-failure/

Stretched tyres – an MOT failure?

Matters of Testing,

30 October 2015 — Hot tips

We're often asked whether ‘stretched’ or ‘Euro look’ tyres are an MOT failure.

To justify a failure, the tyre or its fitment must breach The Road Vehicles (Construction and Use) Regulations 1986 as amended. While the regulations are specific about tread depth, cuts, speed ratings etc, the fitting of a tyre on an unsuitable size wheel rim is not specifically covered.

STRETCH-TYRE_0220-resize.jpgA tyre fitted to the correct size wheel rim

The regulations say that “a tyre should not be used on a road if it’s not maintained in such condition as to be fit for the use to which the vehicle is being put”. This means the tyre must be fitted on a suitable wheel with a suitable valve etc.

This part of the regulation therefore gives you reasons for rejection such as:

  • damaged or misaligned valve stem
  • tyre incorrectly seated on the wheel rim

But how ‘stretched’ would a tyre need to be before it’s in breach of the regulation, and how would you prove it?

STRETCH-TYRE_0207-resize.jpgA wheel rim showing the grooves where the tyre bead should be seated correctlySTRETCH-TYRE_0255-resize.jpgThis shows an example of a stretched tyre without evidence of being incorrectly seated on the bead rim

A correctly seated tyre

stretched-tyre-correct.jpgDiagram of a correctly seated tyre. The side of the tyre bead (1) is not exposed

What an unacceptable stretched tyre looks like

We’ll give you an extreme example in this case. The side of the tyre bead (1) is exposed and the lower edge of the tyre bead (2) is sealed on the rim where (1) should be. This is because the tyre is over-stretched.

stretched-tyre-incorrect.jpgDiagram of an incorrectly seated stretched tyre.

When this happens, the vehicle should be rejected for the tyre being incorrectly seated on the wheel rim. Where this isn’t obvious, the nominated tester should pass and advise.

Another thing to note is that the driver of a vehicle with narrow tyres on wide rims may find that their insurance is invalid in the event of a claim.

If you have any examples of extreme stretched tyres, please email the photos to MattersOfTesting@dvsa.gsi.gov.uk.

Tags: Euro tyres, MOT, MOT fail, stretched tyres, tyre, wheel

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kwijibo_coupe

About F***in time too!

  • Like 1

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kiran_182

That could make some big waves

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Alex

That still sounds like a bit of a grey area to me. It isn't saying stretch is a fail, it's up to the tester to decide and advise.

People also change parts to pass an MOT, a wheel swap is easy, and not declaring mods invalidates insurance too. Doesn't stop people from chancing it.

You get all these stories in the press about stiffer penalties for middle lane hoggers and people on their phones while driving. Doesn't make any difference if there's nobody to catch them! You need a change in mentality, and people are more fussed about being caught than they are about the safety risks. They just assume they won't have a crash, so they'll be fine.

Still, it's good to see some clarity on the subject.

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kiran_182

it does mean cars with streatch can be stopped checked and taken off the road now there is a legal setting albeit loose

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Alex

But by who? That's my point. There aren't enough police around to monitor this. Or mobile phones. Or middle lane hoggers. And mobiles at least are a black and white legal issue, nothing loose about it.

People need to get their heads around being sensible. Like you don't smoke on a petrol forecourt because it's dangerous. Yet I'm always seeing cars driving around - even on the motorway, where you cover a lot of ground in a second - with the driver texting or checking Facebook. Or posting to it. You can bet that most think more about getting caught than causing a massive crash and killing someone.

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wizardmanjm

yeah I have to agree, the middle lane hogging thing has been in action for years yet apparently the first arrest was made not long ago and it literally happens all over the country every day by thousands of people so technically there should have been LOTS more penalties

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Jonnyboi

That second diagram confuses me. makes it look like the bead of the tyre is on its side which it isn't even when stretched?

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Retrotub

That second diagram confuses me. makes it look like the bead of the tyre is on its side which it isn't even when stretched?

I don't get what you are not seeing? On the second diagram the litle square has the wrong two sides adjacent to the wheel surface.

Side 1 should be in the wall of the rim but due to stretch is turned upwards and the side of the square that normally faces inwards is now downwards at the wheel.

It basically means it has to be very stretched before it will fail.

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skeetz23

What happens with the new civic type r.the one that looks like it's on acid.it has stretched tyres from standard does it not?

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kwijibo_coupe

Must be a hell of a wide wheel to stretch a 235 section tyre. They look like they sit nice and flush in the press pictures though.

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kiran_182

What happens with the new civic type r.the one that looks like it's on acid.it has stretched tyres from standard does it not?

It may be the rims are designed with a seat for the stretch if it is factory

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harris.racing

I have a book which tells me recommended tyre sizes for rim widths, and then a tolerance. It is only for one brand of tyre but it's pretty common throughout as they all make tyres so know what they're doing.

The issue is people don't even understand tyres so they don't know what they're messing with when they start stretching them and stuff.

Also some tyres even have printed on them a rim size.

This being an MOT thing and being able to change parts... An MOT is only good st the time of the test, a bulb could fail or anything. Nothing stopping you being pulled over a prosecuted.

And if you have an accident, and your insurance want to check your mods to avoid paying out (which they may well do, they're a business) or even worst somebody gets killed, I'd imagine this grey area could be easily used against you.

Manufacturers don't just chuck a tyre on a car and say awesome this is great, there's a shit load of tests carried out to ensure its safe. I really wouldn't want to do an emergency avoidance manoeuvre on stretched tyres.

And whoever started the whole "just blow them up to 50psi and check them often" is an idiot.

If they're losing air, that would suggest when you're driving it's mildly popping off the bead allowing some air to escape. So when you actually have to rely on the tyre it's likely to just pop off entirely.

Here is an example (let's say using common sizes on a 6n of wheel widths for tyres)

Width/profile/diameter - min/recommended/max

165/45/15 - 5/5.5/6

165/50/15 - 4.5/5/6

175/50/15 - 5/5.5/6

185/45/15 - 6/6/7

195/45/15 - 6/6.5/7

So when people say they're running 8.5's with 165/45/15 they're WELL out of guidelines and any MOT tester not to fail it probably shouldn't be doing MOT tests

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Mclovin

All they are saying is what has been the case all along, stretched tyres are fine as long as they ain't taking the piss. You'd have to be running some hefty stretch to have the bead sitting like that. My 195/40 on 8" will still be fine. If anything this has opened it up so people can run more stretch than they could before, it used to state that tyres had to be fitted within manufacturers guidelines (guidelines that I saw stated that a 195/40 was on it's limit with an 8" wheel. Looking at my wheels/tyres they could go on a wider wheel before there's any chance of them sitting on the side of their beading. Also different tyres stretch in different ways meaning some tyres maybe sustainable to folding over the beading with less stretch than others.

Basically, run retard stretch and risk getting shafted. Run sensible stretch and you're fine.

Edited by Mclovin

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