Tyre temperature

[JohnD]

I'm racing on Yokohama A048s, that have a minimal tread pattern, in 'Medium' compound.
I measure the tread temperature with an infra-red 'gun'. (I know that the ideal is a needle pyrometer, but they are twenty times the price!)
In dry weather and the hot recent weather, I see the tread up to 60C

Talking to someone who has used slicks, they say that the tread should be around 100C.
Are slicks that different from tyres with any tread pattern?
Or is this due to different measurement methods?

Should I try to get my Yokos that hot?

JOhn

[Racer65]

Slicks are a totally different kettle of fish to road based treaded tyres.

It's the spread of temperature that I used to set my pressures rather than one reading. Measure at outside edges and the centre. Shouldn't be more than 10 degrees across all three measurements.

I'd say 100 would be right at the top range and 60 is too cold but I don't run your tyres. With DZ03G's and R888R's I've aimed for around 80 degrees with a needle pyrometer which will give you a very different read to a surface infra red. They're not as expensive as you seem to think.

If the centre is much hotter than the outsides then you're running too high a pressure if it's the other way around it could be too low or too much camber depending on whether it's the inside or outside that is too hot.

[rww]

From the Adams and Page website .

Yokohama A048R Tyres

We have supported the Classic Sports Car Club since it was formed 8 years ago. These are the most popular tyre for circuit racer, used by club and professional competitor alike.

The Yokohama A048 Tyre has a stiffened carcass, which combined with the tread pattern and compound makes it one of the best road legal race tyres in the market today. It is listed in the MSA blue book as a 1b tyre.

The operating temperature for the tyre tread compound is between 45C and 120C. The optimum temperature is 65-95C. When using a pyrometer, and measuring the temperature of the tyre, start by taking the hardest worked tyre first and the inside measurement first. (The inside edge of the tyre should be the most worked, so it is important to get an accurate reading to make sure that the tyre is operating within its parameters).

Temperatures across the tread ideally should vary by no more than 15C from inside to outside when possible.

PRESSURES
Basic guideline settings are given below;

For “M” compound tyres maximum hot tyre pressures should be between 28 and 32 psi.

For “MH” compound tyres maximum tyre pressures should be between 28 and 36 psi.

These are guide line settings only, and can vary for different weight cars.

A 450kg Caterham will have different settings to that of a Jaguar weighing 1000 kilos more. If in doubt please ask.

CAMBER
Although the tyre will work with camber angles of up to 5 degrees negative, the optimum camber angle is 1-2.5 negative if springs and roll stiffness are correct.om the Adams and Page Yokohama Suppliers website.

[ydd]

I am also running A048 tyres. They have been great and a good step from what we ran before.

It wasn't clear what the OP ended up doing but in answer to their question, yes it looks like they should be trying to get more heat into the tyres.

Here is what I understand to be generally held target tyre temperatures for racing tyres. It also includes some suggestion of degradation.

Temp (℃)	Grip Level	Degradation
< 60	Low	Low
65 – 75	Medium	Low
85 – 90	High	Medium
90 – 95	Very High	High
> 100	Medium > Low	Very High

My own approach has been to use this general guidance as a starting point and then adjust once you've got your own measurements.

I wrote a bit more about what temperature your race tyres should be on the blog but this is the main point.
Hope it helps others.

[Trikes]

I've run 48' on my Alfa and the target I ent for was 90. I now run AO50 and I run them at 83-86. Good results all around. ps The AO50's are a improvement over the 48's especially in cold weather.