Advice regarding replacing front Pirelli P zero tyres on 981 Boxster

[peterfrost]

Hi
I have just acquired a 2014 -8000mls 981S
After looking around at many cars I noticed that all the Pirelli shod 20" wheels had scuffing on the outer front tyre shoulders.
Its a bit like trackday scub but that clearly wasn't the cause.
You can here the torture when full lock turning .
However having made my OPC car purchase but changing to a 19" winter set I can see that on the N summer 20" Pirelli shod cracking at the base of tread level( these are 2014 dom -8000miles).
I'm not going to worry about it.
peter

 

[AndrewCS]

Would those with `cracked` tyres consider posting a few pictures please ?

 

[missile]

When I spotted cracking between the treads in the tyres on my old A3, I replaced them asap. What price safety?

 

[paul08]

An observation re the "cracking edges" issue that many have posted about

I got my Spyder (supplied with 20" P Zeros) in Nov'16. The first time I reversed it out of my drive and onto the road, I thought that I must have run over some debris in the road, as there was a definite 'graunching" noise from underneath the car. Got out and checked, and could see nothing. It has happened subsequently, especially when reversing and applying full/hard lock

It would appear that when I apply some hard lock (particularly when reversing) the tread of the tyres is distorting and this is generating the afore mentioned "graunching" as it distorts and then springsback into shape. Never experienced this before, but I am convinced it is coming from the rubber in the tread. If I am correct, this may explain the cracking edges that others have experienced, as the flexing and springing back of the tread blocks on a regular basis may well result in the cracking due to fatigue

Not that well explained, but hopefully you get what I am trying to say/describe

 

[missile]

Hi,
I was alarmed first time I heard the noise you describe. It is a "feature" of the steering geometry. The Ackermann effect is described here https://en.wikipedia.org/...mann_steering_geometry

 

[paul08]

Hi,
I was alarmed first time I heard the noise you describe. It is a "feature" of the steering geometry. The Ackermann effect is described here https://en.wikipedia.org/...mann_steering_geometry

Yes, I am aware of the Ackerman geometry used when turning the front wheels. However, I have never experienced tyres where you can physically hear and feel the blocks of the tyre tread distorting and eventually snapping free of the road surface.

Now whether it is a natural consequence of the wide tyre treads used on my 981 Spyder, or just "poor" design in the PZero tyre, I do not know

Anyone get this on the equivalent Goodyears or Michelins?

 

[AndrewCS]

Not with 235/35 x 19 Michelin PS2`s (6mm) ...

 

[GrahamW]

Mine does the same on 19" rim Goodyear tyres especially when they're cold. As someone said it's just the Ackerman effect.

 

[Boxbrownie]

I get the effect with PS2 235/35-19 (approx half worn).......only at a crawl on full lock though obviously.