Trying to find Tyre tread rules

zappahey

tine wrote:

And spare tyres DO count in an MOT you are right there - if the car has one (it doesn't have to if I remember rightly...) it must be road worthy!

Nope.

http://www.direct.gov.uk/Motoring/OwningAVehicle/Mot/MotArticles/fs/en?CONTENT_ID=10016070&chk=vzsMb2

VOSA_Website wrote:

Wheels and tyres - condition, security, tyre size and type, and tread depth. Spare tyres are not tested

Though, of course, it must be legal when you ever come to use it.

MrsTinks

I stand corrected I was always told it had to be roadworthy but I bow to the superior knowledge ( and the link to the official site lol)

Cumbrian_Male

My understanding is that you must have a minimum 1.6mm tread round the full circumference of the tyre across the central 75%.

So a tyre 200mm wide would need the central 150mm to have 1.6mm all the way round. The 25mm on each edge can be worn to less than this provided it doesn't expose the cord.

The red blocks you describe sound like they are there as part of the tyre construction to give greater lateral stability, so the tread doesn't flex to much during cornering. If the aren't TWI I wouldn't worry.

For the nick in the side wall, then as long as the carcass isn't damaged and bulging you can have a nick 25mm long or 10% of the section size whichever is greater. To work out your section or profile you need the size off your tyre.

For example my tyres are 195 65W 16 so 195 mm wide profile is 65% of width and 16 inch rims. So my section size is 195x65%=126.75mm so cut can be maximum 25mm as 10%= 12.675mm

HTH

PS what tyres are you running, is it a wet weather tyre?

southernscouser

I couldn't be bothered to read all the replies and the OP baffled me! :rotfl:

But, firstly if only part of your tyre is getting worn then the balancing or tracking is wrong! Or something like that!

Also, by law you are not required to carry a spare tyre. However should you carry a spare tyre then you are required by the law to make sure it's road worthy.

Wig

tine, I'm not interested in your forum advice ok, if you have a problem take it up with someone else.

For the 3rd time - my question is not about safety, just leave that for me to worry about.

I've just looked at my 4 tyres on the car and another car and the tread patterns do not have the raised tread areas which my spare tyre has. It's just weird, never seen a tyre tread pattern like it. I'll definately have to remember to put it on the car to use it up in the coming year after my MOT. I can't risk putting this tyre on for the MOT so I'll measure the cut on my other tyre and make sure it isn't longer than 25mm.

Cumbrian male, the weird tyre is a "Nankang passda" doesn't look wet type to me.
Not sure about your method for describing the "section width". I'm going to look that up now. ......Ok this page
http://www.fulda.com/fulda_home_en/test_and_tips/tyre_technology/how_to_read_a_tyre/index.jsp
says the 195 part of the tyre description is the "tyre section width" so a cut can be 25mm or 10% of this figure whichever is greater so if the tyre is a 250 (which is a FAT tyre) or less the cut can be upto 25mm.

Just had an idea, maybe the local gov test centre can advise me if the spare is legal or not and ask them about the weird tread pattern.

Cumbrian_Male

Your section or profile is the sidewall which is expressed as a %age of the width.

What size are your tyres as I'm looking up your Nankang which is a reasonable budget make.

Wig

It is an old tyre I googled nankang passda and found 3 results one german one russian (both just forum mentionings) and one French retail list.
It is 175/70/13

But I think the rules for cut length
http://www.motuk.co.uk/manual_410.htm

half way down the page
a. a tyre has a cut the length of which is at least 25 mm or 10% of section width, whichever is greater, or deep enough to reach the ply or cords

^^^ I inserted the word "or", it is not written very well but I'm sure that is what they mean.

The "section width" or "tyre section width" is the 175, 195, 205 (whatever) bit on the tyre size code.
http://www.fulda.com/fulda_home_en/test_and_tips/tyre_technology/how_to_read_a_tyre/index.jsp
Position 1: The tyre section width is the linear distance in millimetres between the outsides of the sidewalls of an inflated tyre excluding elevations due to labelling (markings), decorations, or protective bands or rims.

Whatever it is it is 25mm for my tyres.

DavidHM

If you're worried about whether the tyre is legal or not, leave it at home when you take the car to the MoT and it can't fail on it.

But if you seriously believe that this:

I'll definately have to remember to put it on the car to use it up in the coming year after my MOT. I can't risk putting this tyre on for the MOT.

is a good idea then you are simply not capable of assessing your own risk. On the one hand you say you're not prepared to bet the (£35?) cost of an MoT on the tyre being safe and legal but immediately beforehand you've said that you're quite happy to stake your own life and the lives of others on it.

Wig

DavidHM wrote:

If you're worried about whether the tyre is legal or not, leave it at home when you take the car to the MoT and it can't fail on it.

As I explained I have two problematic tyres and only 5 tyres/wheels in total, I don't want to waste money changing a good tyre before the test.

a good idea then you are simply not capable of assessing your own risk. On the one hand you say you're not prepared to bet the (£35?) cost of an MoT on the tyre being safe and legal but immediately beforehand you've said that you're quite happy to stake your own life and the lives of others on it.

And you can say this without even seeing the tyre ( or knowing me and my mechanical knowledge and driving style/history) or apparently without reading all of this thread, the tyre IS safe, the local tyre man just told me yesterday it is legal. It is just the weirdest tread pattern I have ever seen, as described in my OP.

I just had a thought that maybe it is a manufacturing fault. and an idea that I could burn or cut away the excess rubber in the treads and bring the treads back to what they should be - but that would take ages

MrsTinks

Wig wrote:

tine, I'm not interested in your forum advice ok, if you have a problem take it up with someone else.

I'm not asking you to be interested... As a BG I am here to help people and occasionally remind them to be nice to each other. I - like others - offered you MY advice, it is your choice if you wish to take it - I don't think there is any need to get rude about it.