Worn tyres and road legalities

[JonP]

Hi all,

 

Does anyone understand the laws point of view with regard to old tyres, road legalities and the MOT? For example, a set of tyres that although the treads were ok, the rubber was cracking?

 

I once had some tyres that I'd never used on my car and they'd been sitting outside for a few years, the treads were fine. I put them on my car and within a week I'd got a major flat tyre... it turns out the rubber had perished.

 

Does this happen with old vehicle tyres or are they made from some long forgotten superformula?

 

Cheers

 

Jon

[Bodge Deep]

Tyre rubber seems particularly susceptible to decomposition from sunlight... I think its the UV. I remember reading a reprint of an article think it was in windscreen that the US Army used to store their tyres in buildings with blacked out windows to prevent sunlight damage. I had some tyres off my old MkII Golf that sat outside for years after i sold the car. The tread was like new but the tyres were utterly knacked!

[Redcap]

Tyres generally have a shelf life of around 6 years (there's normally a date printed on the rim, check this!), and can show signs of cracking even if the car has not been used - whether or not the car has been on blocks; the reason is simple: The compounds in tyres is not a hard rubber, it is a soft rubber, and degrades due to many factors, including ultra violet light, heat, cold, humidity, and so on.

 

Tyres showing this cracking in the sidewalls should be replaced as a matter or importance; similarly, if the sidewall has been damaged (for instance, you kerbed the vehicle, and now there's a bulge or dent in the sidewall of the tyre) the tyre should be replaced.

 

The legal limit for tyre tread depth is 1.6mm across 75% of the width (or 3/4 of the bead, to use the Construction & Use Regulations definition), which is the absolute minimum required for safety; I'd change them out, if you can afford it, well before this - think at least 2mm or even 3mm tread depth as being an acceptable tread depth. As an example, no Traffic Police Car will be seen on the road with tyres with anything less than 3mm of tread - food for thought.

 

Hope the above helps

[JonP]

Interesting! So old bar tread tyres on an old jeep with cracking on the tyre are no different to tyres on a modern car? The MOT test centre should not pass it?

 

Believe me, safety is important to me and I would not compromise for the sake of tyres.

 

Thanks

 

Jon

[Rick W]

depends on how bad the perishing is, they would have to be fairly badly cracked to fail an MOT. Most of the time perished tyres would be an advise on your MOT Advise sheet. At the end of the day its the MOT testers discretion.

[woa2]

In the old days, they used to hide the minor cracks with Black Shoe polish. This was high-lighted in the film 'The World's fastest Indian' where Burt Munro used this method to hide that he was using old tyres with the tread cut off.

[LeeEnfield]

I've heard somewhere, and have no reason to doubt it, although, its quite possibly an'old wifes tale', that tyre blacking type stuff painted onto sidewall of tyres actually helps slow down the cracking process,............as I say, dunno if it has any truth to it.

 

Andy

[julezee001]

If the cracking is deep enough to see the inner structure of the tyre, in the same way as having a cut or a chunk torn out revealing the canvas or webbing it will fail, and should be changed asap anyway.

[LeeEnfield]

If the cracking is deep enough to see the inner structure of the tyre, in the same way as having a cut or a chunk torn out revealing the canvas or webbing it will fail, and should be changed asap anyway.

 

 

 

:sweat:Rightly so.......

[G506]

About five years ago I fitted a full set of 7.50 x 16 Goodyear 'Xtra Grips' to my Landy, and they're showing signs of cracking. Ive been using Xtra Grips for years, I've never worn one out, they've always perished on the side walls.

Very frustrating!

[Tony B]

Best answer, if in doubt change. A S*D if they don't go a B*****D if they don't stop. All that stands between you and disaster is the tyres. Not to mention £1000 a pop for tyre defects. There are a lot of roadside checks round here. One car stopped for no tax, the Police and DVLA or however went over it with a magnifying glass. The end result apart from tax was £6000 in fines for defective tyres. The local tyre places round here still call it the weekend from hell. Quese up the road.

Edited July 11, 2008 by Tony B

[abn deuce]

There are tire skirts or shields for tires that are sold through a verity of sources such as RV dealers that will help protect tires on Vehicles from Ultra violet damage if the vehicle must be parked outdoors all the time the other cause is ozone damage if I m not mistaken , not sure if you can do much about that other that using tire dressing or tire protector like Armour all or other material to try and seal the rubber from harmful materials

[JonP]

Thanks guys. More than happy to change the tyres ;o)

[ja020]

I purchased my jeep in 1988, and I still have the same tyres on I did then (Alliance). The tubes have been replaced, but tyres and tread are still in good condition, and not a word from the MOT man.