Hot Tyres

[caterhamnut]

This is track day related - not race related.

 

When tyres get hot at a track day - say A021's, and 'go-off' - what is happening? The tyre temp goes up, performance goes off, but why. I understand why/how they get hot, but obviously there is a point where they go beyond 'hot and sticky' to 'too hot'.

 

Does this 'performance' come back again once the tyres have cooled down, or has that heat cycle done permanent damage to the tyres future performance?

(and yes Peter I am well aware that hooning and squealing around Croix is not a way to preserve tyres )

 

😬26,000 miles in 13 months!

angus@tinyworld.co.uk

[mav]

I believe that when the rubber over heats a chemical reaction takes place that causes the rubber to be less grippy. I do not know if the performance will return completely or partially

 

Regards,

 

Martin

[J.R.]

Angus

 

Generally speaking with relatively newish road tyres they will recover to the extent that you will not be able to tell the difference.

 

In racing where one competitor is on ACB10's or A032R's often they will lead for a couple of laps until "the tyres go off" - analysis of the lap times will actually show them dropping back due to the slick shod racers tyres reaching their optimum temperature and lapping faster. The lap times of the road tyres do not increase significantly and will usually recover for the next race.

 

Hard (endurance or GT) compound slicks on a light vehicle like the 7 usually do not "go off" during a race but lap times will gradually deteriorate on subsequent meetings as the tyre ages (correct storage is quite important).

 

Soft compound slicks if overdriven will go off and reduce lap times and will only partially recover for the next meeting.

 

The front runners wiil often sell off their part worn slicks after just one meeting. The rest of us determined to get every penny of wear out of our slicks struggle with progressively worsening handling. When changing to new slicks often the initial slow "bedding in laps" will be as fast as the old tyres and the car will lap as quick without trying compared to the lurid slides etc of the old ones.

 

Bit of a long answer, - I suspect that the A032R super soft compound will behave more like a slick than a road tyre, which we may see in november at Croix I hope.

 

 

[caterhamnut]

Thanks John - due to unavailability of 32r's we have 21's fitted. Croix last weekend started off wet - which was great fun. They let us visiting Caterhams use the pit garages. Soon dried out.

Almost certainly will be there in November.

 

😬27,000 miles in 14 months!

angus@tinyworld.co.uk

[felix.klauser]

> (correct storage is quite important).

 

What would you describe as correct storage?

[Nick M]

Lurid slides you say...

 

So, where can I get some part worn slicks ??? 🤔 😬

[eric]

I phoned to Yokohama yesteday,

 

for a question concerning A 539 on 15" and a track days use

they told me that the A539 will suffer on a circuit and will never recover its qualities.

 

 

they advise for a such use the 038 which is 195 50 15" but made for

[eric]

As everybody, or most people use road tyre on circuit (for fun not proffessionals)

 

Did they notice some changes in their tyre behaviour ?

 

Advices welcome

[Fast Westie]

Eric

Road tyres will work on a circuit, but will not produce as much grip. They are alright for fun since you are not looking for the ultimate lap time. The main problem you get is "beading" where rubber peels off the tread and collects in the grooves in beads. This takes a while to wear away on the road when the tyres cool down.

 

I did not notice much change in my Yoko A520s after using them on the track.

 

Angus & Tessa

I am not sure if you will really overheat your tyres at Croix. I checked the 21Rs on a friends car (he only has 85bhp though) after 20mins at Croix and they were only up to 45C. You would need to be up to 100C for them to really "go off"

 

Felix

Correct storage is in a cool dark place on a rack.

 

The car in front is a Westfie1d

[Fast Westie]

Eric

Road tyres will work on a circuit, but will not produce as much grip. They are alright for fun since you are not looking for the ultimate lap time. The main problem you get is "beading" where rubber peels off the tread and collects in the grooves in beads. This takes a while to wear away on the road when the tyres cool down.

 

I did not notice much change in my Yoko A520s after using them on the track.

 

Angus & Tessa

I am not sure if you will really overheat your tyres at Croix. I checked the 21Rs on a friends car (he only has 85bhp though) after 20mins at Croix and they were only up to 45C. You would need to be up to 100C for them to really "go off"

 

Felix

Correct storage is in a cool dark place on a rack.

 

The car in front is a Westfie1d

[caterhamnut]

you could not really touch our rear tyres, so not sure how hot they actually were - but we were sliding around a lot (intentionaly!)

All the tyres have got a lovely blue 'tempered' look around the outside edge now (which I know from the 32's soon goes)

 

😬27,000 miles in 14 months!

angus@tinyworld.co.uk

[Fast Westie]

Angus & Tessa

Too hot to touch is normally 50C, so you my estimates may not have been too far out . You should try and borrow an Infa Red temp gun next time you are at Croix.

 

The car in front is a Westfie1d