Tyre question

[Banish Goat]

Do tyres have less grip as they wear? I don't mean when they're worn out but say at 50% tread.

I'm convinced my tyres have less grip than they used to in the dry and yet they have 6mm of tread across the whole tyre. Could it be related to heat cycles or similar or perhaps just my imagination?

[Orangecurry]

Banish Goat said:

Do tyres have less grip as they wear? I don't mean when they're worn out but say at 50% tread.

Yes - for instance Pirelli P-zeros quite rightly have a reputation for excellence... in the dry at least. However, the very VERY good grip and handling does IME tail-off, once the tyre is 50% worn or so. Therefore I won't buy them again.

Banish Goat said:

I'm convinced my tyres have less grip than they used to in the dry and yet they have 6mm of tread across the whole tyre. Could it be related to heat cycles or similar or perhaps just my imagination?

I'm not even going to begin to speculate why, but it is not your imagination.

[Banish Goat]

Orangecurry said:

Banish Goat said:

Do tyres have less grip as they wear? I don't mean when they're worn out but say at 50% tread.

Yes - for instance Pirelli P-zeros quite rightly have a reputation for excellence... in the dry at least. However, the very VERY good grip and handling does IME tail-off, once the tyre is 50% worn or so. Therefore I won't buy them again.

Banish Goat said:

I'm convinced my tyres have less grip than they used to in the dry and yet they have 6mm of tread across the whole tyre. Could it be related to heat cycles or similar or perhaps just my imagination?

I'm not even going to begin to speculate why, but it is not your imagination.

Thanks OC - funnily enough these are P-zeros I'm talking about.

I'm intrigued now as to why it is.

[Orangecurry]

I thought they might be

Pirelli are an enigma to me - the compound appears 'hard' (and so wet grip is relatively poor, especially the P6000) and the P-6000 tyres last forever, but the P-zero seems to have the qualities of both a hard and a soft compound.

If you are happy/rich enough to replace your tyres when half worn, AND you live in a country where rain is rare, I'd go for the P-zeros

IME Michelin Pilot Sports are THE best all-round tyre, but they are expensive.

I remember dinging one (rear on a RWD) in a pothole, damaging the sidewall; I decided to replace both rear tyres - 255/35/17 IIRC ain't cheap, but they are worth it.

[Munter]

I swear I saw a diagram of the cross section of a tyre that explained this. Cant find it now though. But if my memory is correct the tread blocks have a ridge of hard compound with soft over the top. So as the soft wears away more and more of the hard compound is slowly exposed. However I think the idea is that with heat cycles the "hard" compound softens.

Could verywell be talking rubbish, but I'm sure it's something to do with different compounds at different wear depths...

[Banish Goat]

Munter said:

I swear I saw a diagram of the cross section of a tyre that explained this. Cant find it now though. But if my memory is correct the tread blocks have a ridge of hard compound with soft over the top. So as the soft wears away more and more of the hard compound is slowly exposed. However I think the idea is that with heat cycles the "hard" compound softens.

Could verywell be talking rubbish, but I'm sure it's something to do with different compounds at different wear depths...

I think I read a similar thing somewhere - it explains why bald tyres have less grip, even in the dry, than a treaded tyre. Seems a bit harsh to 'harden' the compound at 50% though! Bastids.

[Munter]

Banish Goat said:

Munter said:

I swear I saw a diagram of the cross section of a tyre that explained this. Cant find it now though. But if my memory is correct the tread blocks have a ridge of hard compound with soft over the top. So as the soft wears away more and more of the hard compound is slowly exposed. However I think the idea is that with heat cycles the "hard" compound softens.

Could verywell be talking rubbish, but I'm sure it's something to do with different compounds at different wear depths...

I think I read a similar thing somewhere - it explains why bald tyres have less grip, even in the dry, than a treaded tyre. Seems a bit harsh to 'harden' the compound at 50% though! Bastids.

Well yes 50% would seem a bit early. Could simply be the more worn the tyre is the less heat generated by blocks moving around, and this type of tyre needs that heat? The solution being driver harder!

Edited by Munter on Thursday 12th June 10:10

[sean19]

I have a question.

I have recently changed from Toyo's on the front to some rubbish 'Marshal' as I needed them for the MOT.

The sidewalls on them are so weak, if I put them to say 38psi (from 32psi) will this reduce the tyre roll or just damage the tyre?

I dont mind if they wear quicker etc. to be honest can't wait to take them off!

Thanks.

[Orangecurry]

sean19 said:

I have a question.

I have recently changed from Toyo's on the front to some rubbish 'Marshal' as I needed them for the MOT.

The sidewalls on them are so weak, if I put them to say 38psi (from 32psi) will this reduce the tyre roll or just damage the tyre?

I dont mind if they wear quicker etc. to be honest can't wait to take them off!

Thanks.

It should firm up the sidewall, but depending on the tyre width you will get more wear in the middle, and wet-handling might be amusing....

[sean19]

Orangecurry said:

sean19 said:

I have a question.

I have recently changed from Toyo's on the front to some rubbish 'Marshal' as I needed them for the MOT.

The sidewalls on them are so weak, if I put them to say 38psi (from 32psi) will this reduce the tyre roll or just damage the tyre?

I dont mind if they wear quicker etc. to be honest can't wait to take them off!

Thanks.

It should firm up the sidewall, but depending on the tyre width you will get more wear in the middle, and wet-handling might be amusing....

Is it safe to run a tyre at 38psi daily?
I think the MAx pressure is 47psi or something simular, but Im guessing thats not 'running' pressure.

[Orangecurry]

38 psi?

depends on the tyre - recommended pressure on one of my cars is 44 psi on the rear, 36 front.

Another has 38 front, 34 rear; but that is to firm-up the utterly ste sidewalls... of a well-known premium-brand tyre.

Why not bump-up your pressure in 2 psi jumps, measured cold, until the tyre feels a bit better?

Edited by Orangecurry on Thursday 12th June 10:39

[Munter]

Orangecurry said:

38 psi?

depends on the tyre - recommended pressure on one of my cars is 44 psi on the rear, 36 front.

Another has 38 front, 34 rear; but that is to firm-up the utterly ste sidewalls... of a well-known premium-brand tyre

Then my MX5 runs 26psi all round on the road and I up that to 28psi (cold) on track. It depends on the weight of the car and width of the tyre and profile and so on. If you get the pressure too high you'll get less grip and wear the center of the tyre. Get it too low and the extra friction can overheat the tyre and melt the rubber causing less grip and potentially a blow out.

Basically unless you'r going to monitor the tyre wear and pressure regularly just set them to standard and change the tyres for something you actually want when you can.

There was a story I heard that back in the 60's ish they set tyre reccomended pressures by running them lower and lower until the tyre burst. Then upped it a bit and set that as the recomended pressure.... It's probably a bit more scientific now.

[Dunlop Tyre]

Hope you don't mind me coming in on this.

Give me a call on 01902 453097 and I will take your e-mail and send you an article on tyres as they wear.

Alternatively if you'd prefer e-mail me your contact details via our website on http://www.dunloptyres.co.uk/contact/ select Product Technical

Pete @ Dunlop

[Orangecurry]

Dunlop Tyre said:

Hope you don't mind me coming in on this.

Give me a call on 01902 453097 and I will take your e-mail and send you an article on tyres as they wear.

Alternatively if you'd prefer e-mail me your contact details via our website on http://www.dunloptyres.co.uk/contact/ select Product Technical

Pete @ Dunlop

why would anyone mind someone commenting who knows what they are talking about?

Can you not post the article up here please?

[S13_Alan]

sean19 said:

I have recently changed from Toyo's on the front to some rubbish 'Marshal' as I needed them for the MOT.

The sidewalls on them are so weak, if I put them to say 38psi (from 32psi) will this reduce the tyre roll or just damage the tyre?

Got the same problem.. running the same pressure on mine otherwise turn in is just soooo bad.

I'd never have put them on the car, previous owner did, and plan to replace them later this month, probably with Michelin PS2s as they seem to work well on these cars, plus get a complete geometry setup.

[sean19]

S13_Alan said:

sean19 said:

I have recently changed from Toyo's on the front to some rubbish 'Marshal' as I needed them for the MOT.

The sidewalls on them are so weak, if I put them to say 38psi (from 32psi) will this reduce the tyre roll or just damage the tyre?

Got the same problem.. running the same pressure on mine otherwise turn in is just soooo bad.

I'd never have put them on the car, previous owner did, and plan to replace them later this month, probably with Michelin PS2s as they seem to work well on these cars, plus get a complete geometry setup.

Well it was on for MOT and the inner walls of the TOYO's were cracking and the tester wouldn't pass them. He's a good mate of mine, but he said they need changing so I just put the cheapest tyres on possible. Normally I'd go for quality, but EVERYTHING has come at once.

They were at 27psi when I first had them, I thought they had forgot to inflate them!!

I never realised how important quality tyres really are.

[Dunlop Tyre]

Hi Orangecurry, I can only really respond to either a generalised question or one about our own product. If you or your colleagues on the Forum do have tyre questions we are happy to try and answer either by phone or the contact us on our site. Tel [phone] or http://www.dunloptyres.co.uk/contact/ and then then select product / technical

As a note if you or S13_Alan are wanting a tyre thats good for cornering and feedback (depending on the fact it's in the size you require) have a look at our Sportmaxx TT which has only just come out. See http://www.driversknow.co.uk/tyres/details/car/sea... or http://www.sportmaxxtt.com/
The tyre has Kevlar fibre pulp in the apex area of the sidewall which should help.

Tyre recently reviewed well in Track and Race Cars June Magazine.

Pete

Edited by Dunlop Tyre on Thursday 12th June 15:37

[IanMorewood]

Big difference is only noticeable in the wet.

[sean19]

IanMorewood said:

Big difference is only noticeable in the wet.

I have to disagree, the Toyo's that were fitted were superb (for my car atleast) the new ones have so much tyre roll it's a joke, which in effect means that when cornering sharp you have less contact area, reducing grip, causing more understeer!

Well that's what it feels like to me, but I am no expert!