Unusual tyre wear DZ03G?

[M.C..]

I have been using the Dunlops for a while now and seem to keep getting a weird wear pattern, where it is creating a staircase type pattern.
I run 30psi hot normally but do up the front pressure to 32-34psi hot sometimes as the main loaded tyre begins to roll and wear the edge.

Sorry about the bad picture but you can see how it wears at a angle down to where the thread is cut into the tyre then it has a square wall upto the surface and back down again.

 

[MarkX]

Isn't that to do with heat and a lot of negative camber?

 

[M.C..]

Isn't that to do with heat and a lot of negative camber?

May well be, I do run just over 2 deg of negative camber

 

[Tony Hunter]

I've never had that trouble with mine, but then they never go over 30 psi.

You will need to take tyre temps to find more out tbh.

 

[172_Tom]

Have similar wear on my AD08Rs that have been on the front. Also running 2 and a bit degrees negative camber on the front, similar pressure and had the outside edge wearing more. I'm running Eibach pro-kit springs so still get quite a lot of body roll on track and I suspect even with the camber on the front, the wheel/tyre is leaning over more than would be ideal.

 

[M.C..]

I am leaning towards suspension as I am on standard shocks and cooksports, just wondering if they are not upto the job?

@Tony Hunter you run ASTs don't you?

I have watched some videos about weird tyre wear on bikes and it mainly comes down to suspension, rebound damping is a main cause, I may get me a cheep eBay laser thermometer thing to find out what is happening next time I am out.

 

[172_Tom]

I reckon we're getting positive camber during cornering which is causing this wear and the extra wear on the outer shoulders. Those with coilovers set up for track use should have less body roll and therefore maintain a better camber angle during cornering which is kinder to the tyres.

I have one of those eBay infra red thermometers - I'll try and remember to take a number of readings across the tyre next time out, though I don't think it will show much as I expect the tyre temperature to even out over my cool down lap.

 

[M.C..]

The cooksports are quite firm but think the shocks are becoming the weak point as the tyre is putting more load into it than it was designed to cope with, causing the tyre to do the work.
I think you are right with the body roll wearing the edge.

 

[NorthloopCup]

Only just seen this. That's definitely down to your suspension not being stiff enough mate. It's rolling over the edge of the tyre and running positive camber. You'll only combat that by stiffening the suspension (springs and dampers) or run more camber up front.

 

[M.C..]

Cant get any more camber the bolts are maxed out.

 

[NorthloopCup]

Cant get any more camber the bolts are maxed out.

You could always slot the holes in the damper body. Or run with some Ast top mounts to gain a bit more. Personally though I'd be looking at changing the suspension mate.

 

[M.C..]

I think it is the next route, don't really want to buy the top mounts as I have the PMS top mounts and strut brace.
I keep looking at the AVOs and BCs

 

[172_Tom]

Are you sure? I think mine will allow more camber. The Cooksports are also a bit lower than the Eibachs I have so that should give you more camber before the adjustment that the bolts give you come into play. The position of the tab on the washer will adjust the range of camber the bolt will give you.

A few options:
1. Better suspension as @NorthloopCup said. Probably looking at coilovers with a spring rate designed for track to get the stiffness you need for DZ03Gs
2. Tyre downgrade to AD08R/595RSR/NS-2R so you're not asking as much of the suspension. May still need more camber to reduce shoulder/step pattern wear.
3. Continue as you are but look at adding more front camber. You could also have the tyres swapped left to right to even out the wear on the shoulders.

Be interested if you do option 2 or 3 to see what the results are. :smile:

 

[M.C..]

Yes bolts are at max, I think the passenger side would give more but it was just set to the same as what the drivers side would go to.
I use 595RSR as my wet tyre

 

[NorthloopCup]

I think it is the next route, don't really want to buy the top mounts as I have the PMS top mounts and strut brace.
I keep looking at the AVOs and BCs

Either of those options will be good enough mate.

 

[M.C..]

Mick took me out in his car at Donington the other week and the BCs seemed quite good.

 

[NorthloopCup]

Mick took me out in his car at Donington the other week and the BCs seemed quite good.

Yeah from what I've seen they're a good bit of kit tbh

 

[Tony Hunter]

Those cheap laser temp things aren't much god for tyre temps, alright for discs etc.
You should be looking at a 10 deg spread across the tyre.

 

[Mini182]

You want a pyrometer wit a tyre probe really. I keep thinking about getting one myself.

 

[Ph1 Tom]

I had the same issue. Only one solution...Better suspension

 

[Tony Hunter]

You want a pyrometer wit a tyre probe really. I keep thinking about getting one myself.

That's what I've hot James, well worth the money, it will tell you all about your suspension set up too.

 

[AdamR]

Agreed. IR gun is next to useless for tyres unfortunately.

Does the car suffer a lot of understeer? Any vids? Looks like the tyre is getting 'scrubbed' across the track surface to me.

Do you have a rear ARB?

 

[Shocker]

Agreed. IR gun is next to useless for tyres unfortunately.

Does the car suffer a lot of understeer? Any vids? Looks like the tyre is getting 'scrubbed' across the track surface to me.

Do you have a rear ARB?

As above scrubbed around corners
This is caused by you driving hard on corners the treadblock goes down and fills the gaps thus your tyre wares evenly on a corner but when you come in or on the straights the treadblock pops back up into position thus the saw tooth effect
My kumho v70 used to do this when you have more time going fast around corners than you have time going straight

Ps - this just means your good on corners and getting max out of the tyres

 

[AdamR]

Agreed, to a point. Though if the rears aren't showing the same wear pattern it indicates a handling balance issue, with the fronts doing all the work, hence the rear arb question

 

[M.C..]

Agreed. IR gun is next to useless for tyres unfortunately.

Does the car suffer a lot of understeer? Any vids? Looks like the tyre is getting 'scrubbed' across the track surface to me.

Do you have a rear ARB?

I don't really get any understeer, I do have a Whiteline ARB.
As for the rears showing the same pattern TBH I can't remember as I have swopped them from front to rear to even the wear so all now show the same pattern now.
This has been happening from the first day I used them (second set now), I used Federals 595RSR for a full day and a hot evening before the Dunlops but they never showed the same pattern as these.
So could be suspension not coping with the better tyres?

Here is a video from Rockingham a couple of weeks ago (have not sorted Donington out yet)