Odd tyre wear

**glytch** · 11-12-2006, 01:35 PM

Hi All

I had a motorkahna event on sunday (see the Maxaction thread in Tracktalk) and ended up destroying my tyres after pushing very hard to get some rather competitive times.

I have been running 28psi in the tyres every time I have competed, which had been working well, it was rather warm - officially 26 but track temp was a fair bit higher. I had some big understeer moments towards the end of the day, but the last two runs are what really did the damage. the course was 80% long, fast left handers. The damage was mainly to the front right, though a little damage occurred to the front left

I am suspecting it may be an alignment issue, along with some serious understeer, but the wear pattern is odd. It could also be worn shocks in the front :\ Has anyone seen wear like this, and know what can cause it?

Luke

**RONA** · 11-12-2006, 01:44 PM

Originally Posted by glytch

I am suspecting it may be an alignment issue, along with some serious understeer, but the wear pattern is odd. It could also be worn shocks in the front :\ Has anyone seen wear like this, and know what can cause it?

I have seen wear like that on VT-VZ commodores which lean very hard on the outside tyre during conering and tear the edges of the tread to pieces.

The rona has also done it due to a blown shock on one side up front.

**MR22ZZ** · 11-12-2006, 01:44 PM

possibly too much toe in on the front.

more camber may also help, though the camber look ok from what I can tell in the pics, but it's always hard to judge when the wheels are slightly turned like that.

**"Z" UTE** · 11-12-2006, 02:22 PM

In my humble opinion, that wear pattern is caused by stuffed shock.

cheers Chuck.

**swan86** · 11-12-2006, 02:42 PM

Scolloping of tyre wear like yours generally indicates poor/failed shock absorbers..
As the wear is predominately on the outer edge, this could mean incorrect wheel alignment.. however outer tread wear could also be semi-intentional due to the car's suspension set up or driver abuse on the track

**glytch** · 11-12-2006, 03:11 PM

Thanks for your input people. Its summer break now no more events untill next year so I will check out the shocks and of course alignment will be redone too. Just need to save up some $$ to get a new set of Advans...

As for driving abuse - possible - I did drive it hard, but not really harder than last time and it was similar conditions on an identical track layout. Also, I dont intend to blow my own wistle, but I am generally smooth and clean around the corners as I need to maintain speed due to my lack of power. ie I tend not to come in too hot under brakes or turn sharply on the corners.

**kingmick** · 11-12-2006, 04:47 PM

Easy to tell if have the info! whats the suspension specs? toe,caster and camber etc!
Motorkahna you shouldnt have you tires going off to much, unless your over heating them to much with low pressure! lower pressure flex's the sidewalls more so the tires heat up faster and go off faster!

How old are the shocks and when was it last aligned? is it even bad wear on the seprate corners?

**Cameron_Datto** · 11-12-2006, 08:17 PM

More Neg Camber and Pos Caster Needed , The outside of the tread is doing most of the work by the tread Depth compared to the inside tread , The outside of the tyre tread is Heavily loaded causing Tread flex with will give you the scolping on the outside , Being a motorkahna car your more likely using more steering angle to make the car turn tighter radius corners at low speed, By using more positive caster it will induce more negitive Camber with the more steering angle you use ( cause the wheel to lean over the more you turn the wheel ) ,
You might have to change your driving style or car set up, to induce the car into oversteer , So the rear is doing some of the steering for you , Have you got a Good Hand brake , ? stiffen the rear up These are some ideas you could try , not saying its the correct thing to do on every corner .