Thanks Stuart, I phoned and was told they have no specific restrictions on slicks. Obviously I'll be mindful of the weather, not only having alternative tyres in case it's wet, but making sure they're warmed up properly given likely December temperatures.
Before Cadwell I discussed the issue with Chris at Circuit Days - some insurers impose restrtictions, some don't, and if it hadn't been for that he would have been happy for me to use them.
He did say, though, that the insurers are becoming more restrictive and likely to outlaw slicks/cages generally at trackdays next year. This is something that's happened in bike trackdaying (which has been mainstream for longer than car trackdaying) with slicks/racebikes being confined to their own session. This is more of a compatibility thing, to reduce speed differential within a group. Having done a few years of bike racing I can only agree with this one - a bike racing class has closely matched machinery, but in open practice sessions anything goes and it can be scary
As for rollover probability, I'm not convinced it's any more likely than with trackday tyres. Sure, going from road tyres to trackday tyres you increase the cornering forces, and increase them potentially further with slicks. But, how handleable it is depends on progressiveness and predictability of a slide more than anything.
cheers
Andy
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