mike_nunan

Hi Peeps,

With Donington just over a month away I'm starting to think about tyre options for the day. I know it will probably pee with rain anyway, but just to be on the safe side I'd like to get hold of some track tyres. Even if it does rain, they'll stand me in good stead for next year.

I've re-read all the previous posting about slicks, but there are still a couple of points of confusion.

Firstly, what difference (if any) is there between:

1. Moulded slicks
2. Hand-cut slicks
3. Grooved slicks
4. R-rated tyres?

I'm guessing that moulded and hand-cut slicks are two different ways of creating "groove slicks", and that R-rated simply means that the tyre is approved for road use. Is that right (DarrenS - I know you're a font of knowledge on this subject).

Are any of these likely to make a good all-weather tyre, so I don't have to cart two sets of wheels along with me?

Another thing I've heard is that R-rated tyres don't last long on the road. Does that mean they won't last long on the track either, or is it a case where they can stand high temperatures better than road tyres but are softer at road temperatures and wear quicker?

Any info gratefully received, as is any update on the best place to get these things (Fairfield Motorsport seeming like the cheapest for pure track tyres, from previous postings).

TIA

-= mike =-

Lee

Can I add..if anyone knows of any places to get part-worn slicks feel free to mention them...

Darren Soothill

Well here goes I know you are expecting an answer Mike!!!!!

Moulded slicks:-
Basically a slick tyre with some tread moulded into it the FIA stipulate that the rally cars must run on a 17% (I think) moulded slick this means that 17% of the tyre must not be rubber that can contact the road!

Hand Cut Slicks:-
A man has attacked a set of slick tyres with a tyre cutting tool and removed some of the rubber depending on what you are wanting to do with them then different patterns can be cut into them.

Grooved Slicks:-
These typically have a couple of groves around the circumference. I would class these as moulded slicks!

R Rated Tyres:-
These are thinks like the Yokohama A032R and the P Zero C. These tyres are road legal but the compounds are softer than you would get on a normal road tyre and the tread depth is typically very small around 2-3 mm. This is one of the reasons that these tyres do not last very long with road use.

The main problem with a road tyre is that it over heats because of the amount of tread block movement and this allows the rubber to literally peel off the tyre leaving you with what can feel like warped disks when you get them too hot and hit the brakes as the rubber builds up around the circumference.

The problem with R rated tyres is that they are not designed to handle the motorway miles that normal driving puts on them which is why the mileage is lower.

My suggestion would be to get a set of slicks to but on a set of wheels and then just use the normal road tyres if it is raining. If it is not raining then it will not take long for a dry line to develop around the track. So long as you dont have any surface water then the slicks should be fine.

Just a quick answer because I am at work!!!

Cheers

Darren

mike_nunan

Thanks Darren,

I knew you'd deliver the goods

Sounds like it's a toss-up between regular slicks and R-rated then. Anyone got any experience of R-rated tyres in the wet? Are they really hopeless? If not, they sound like a good solution - I can put them on for the odd bit o' road romping as well, plus I don't need to carry a spare set of wheels up to the track (a major consideration if you've got an STi fixed rear seats).

Final questions Darren: something like the Yoko A032R, what is that roughly equivalent to in terms of the slick compound scale, any idea? Also, is that compound scale common between all manufacturers, or is it just a Michelin thing?

TVMIA

-= mike =-

Darren Soothill

Id go the the regular slicks because you can get them for £50 a corner brand new as oppose to R rated tyres been the same price if not more than road tyres!!!

I end up with 2 wheels on the back seat and 2 in the boot when I go to trackdays just use a car blanket to protect the seats!

Id suggest you invest in some rubber gloves as well as brake dust is a bugger to get off you hands!

The compound scales are specific to each manufacturer so I have used S4B's from Michelin which is a hard compound rally tyre as oppose to an S9 which is a hard compund circuit slick! I have been told that a hard compund rally tyre is equivlent to a medium compund circuit tyre! Dunlop use a different numbering scheme!

It is also worth checking if there are any reccomended fitting instructions. The tyres have certain information that is printed on one sidewall only and with some tyres they want you to have this all on the same side of the car so in effect the slicks are directional! I cant remember whose web site this was on but for there tyres they wanted you to have the additional information always on the right hand side of the tyre!

I seem to have had some difficulty in trying to get hold of informaiton from manufacturers on racing tyres and most of the informaiton I have had has come from various telephone conversations!

I am hoping that when I go up to Autosports international in January that I may be able to get some better information.

Darren