How do I know when my tyres are shagged and no longer useful on the track?

[tricolore]

Yeah yeah, I know, another bloody tyre thread...
I just wondered if anyone could give a quick lesson on tyres?
After my last track day it looks like the rubber has been pushed from the edges upto the middle of the tyre. And in some areas it looks almost crystalised rubber.  it has a shiny look to the rubber and the tread lines are also irregular, as if the rubber has moved the tread grooves.
The tyres are Dunlop Sportmaxx I know not a track tyre. There is still heaps of tread on them so it would be a shame if they were no good.
I mentioned to George and Shaun a Dmoto that I might look at getting some new tyres they recommended Pirelli SuperCorsa. Interesting point was that they said they have a benefit that you can "sell them to road guys as they are tredded when your done with them" That would suggest that the tyres are no longer any good even though they have tread 
Cheers.

[mattyvas]

Saw the rubber on the MV at D-Moto.
They do look a little shagged but Dock might be able to help you a little more.
I have Supercorsa Pro's now and they are great, excellent for track use. Not much good in the wet pretty slippery.

[spotcom]

Tyres are relatively cheap.  Accident repair is relatively expensive. 

I agree with Mattyvas - the Pirelli Supercorsa Pros are great track tyres.  I also agree that they're not much good in the wet.

I've been told that the D209 Sportmax GP Racer that they use as the control tyre for Formula Extreme is a pretty good tyre. I've not tried them yet, but will be doing so this weekend. I'll let you know how they go!

[tricolore]

Tyres are relatively cheap.  Accident repair is relatively expensive. 

I agree with Mattyvas - the Pirelli Supercorsa Pros are great track tyres.  I also agree that they're not much good in the wet.

I've been told that the D209 Sportmax GP Racer that they use as the control tyre for Formula Extreme is a pretty good tyre. I've not tried them yet, but will be doing so this weekend. I'll let you know how they go!

I am hoping to get some answers sooner, I will be ECR on Monday. If I need to ditch the tyres I need to do it by the weekend.

[hambo]

not sure if it helps but the dunlop guys have just upgraded the qualifier......and if you buy a set of the new ones at EC from the tyre guys there you get a free track day......their no is 0397636277......might be worth a try .....even if you dont want a dunlop they have a good range of michelin and Perilli........good luck on the weekend..........remember slow into 2 means fast out...hahaha [moto]

[mattyvas]

Then you can get Supercorsa's everyday of the week from MCAS for $450.
You'll have new rubber for the weekend and a big  on your face.