Tyre hardness

[Sam_Q]

- Is tyre hardness marked on a sidewall of a car tyre?

- Is it worth making something to check it?

- how good a guide to grip is the hardness of a tyre?

I am basicly sick of playing roulette with tyres when I buy them, as what was once said on autospeed even the crapiest tyres is highly recomended by the company making them.

[IN 05 NT]

softer tyre generally equals more grip.... ie have a look at drag slicks....you can almost dig a hole with your finger nail,

but you scrifice tyre life for for grip,

if you pick up a set of OLD tyre's, they will be DRY and hard, and will be shocking for grip,

are we talking street tyres? or track tyres,....its better to have a 2nd set dedicated for the track, that way you dont kill $500 a corner on tyres going to the local shops for groceries,

blake

[Sam_Q]

its for quick street, what I am specificly talking about are tyres I find at tyre shops or wreckers that dont look very old at all but I dont know if they soft tyres or not. Anyone who tells me to nto use them can get lost as I have found some really grippy Jap tyres though these sources before.

So there is some merit in making my own hardness gauge? I was thinking of using a lathe ot make a centerpunch like point that is pushed down with a spring attached to my dial gauge.

[roadsailing]

just get bridgestone adrenalins

grip wont be related to hardness, as plenty of soft tyres are "squidgy"

[Sam_Q]

never heard of them , whats they wear vs grip like?

[Chrisso]

Have a look for a post by delinquent (sp?) in the general car section IIRC. Tyres have a treadwear, traction and ?something else? rating. Roughly, if the treadwear, which is numerical is up towards 500 then they're a hard compound lottsa kms type of tyre. The aforementioned bridgestones have a treadwear of somewhere around 240-260, can't remember off the top of my head.

Regards,
Chris

[Sam_Q]

do you know where I can find out more about this? any chance of digging that link up?

[Hiro]

never heard of them , whats they wear vs grip like?

Full name is Bridgestone Adrenalin RE001, they replace the upper end of the GIII and S03 range.

[oldeskewltoy]

Not sure about down under...but tires for sale in the USA are required to have a few things listed on them at sale. temp rating, traction ration are 2 of the three... the last one is usually a numerical rating. Tires with ratings under 200 are usually the softest, with competiton tires usually rated at or near 60

[M.J.H]

do you know where I can find out more about this? any chance of digging that link up?

http://toymods.net/forums/showthread.php?t=26768

There you go.

Like Shinny said, Just get the Adrrenilines.

[mikie_121]

Here is an extract from the Michelin website. Apparently Aussie tyres don't have to have the tread wear markings, etc.

*----------------------------------------------------------------------------------------------*
North American Standards

The North American tyre market requires all tyres to be marked with UTQG ratings. The paragraphs below explain what these markings mean and how to read them.

Quality Grading
UTQG. This means Uniform Tyre/Quality Grading and is a requirement for all tyres sold in the USA. It consists of three gradings, based on tests carried out under conditions specified by US Government Regulations. The gradings are for:
wear
traction
temperature
Tread wear
The grading is a number which represents a comparative grading of tread life related to a defined standard which is rated 100. Therefore a tyre rated 240 would last 2.4 times longer under the test conditions.
Tread wear grades typically range from 60 to 500, in more than 20 point increments. It's important to remember that the actual life of any tyre is determined by the road surface quality, driving habits, inflation pressure, wheel alignment and rotation it experiences.

Traction
Traction grades indicate the measurement of a tyre's ability to stop a car in straight-ahead motion on wet test surface pavement. They do not measure straight-ahead acceleration. It is important to remember that the traction rating tests are performed only for straight-ahead sliding on concrete and asphalt surfaces that have a specified depth of water which simulates most road surfaces in a rainstorm. The ratings that result from these tests may not apply to cornering traction or peak values of straight-ahead braking force like those experienced in non-skid braking tests. Traction grades range from A to C, A being the highest attainable grade.

Temperature
Temperature grades also range from A to C, with A being the highest. Temperature grades represent a properly maintained tyre's ability to dissipate heat under controlled indoor test wheel conditions.

Example: Tread wear 140 Traction A Temperature B

*----------------------------------------------------------------------------*

Hope this helps
Mikie

[pauljones1976]

I'd have to agree that hardness does not indicate the grip level of the tyre. Traction ratings are sus too. I have read reviews on tyres which prove that tyre compositions and designs can cause grip levels to increase and decrease at different load directions. For example, two tyres of the same traction and hardness rating can behave very differently - one may corner extremely well but stop poorly while the other may do the opposite.

If you are looking for straight line grip (drag racing) I have TOYO R888 on the back of my RA23 and they are incredibly sticky in a straight line.

Cheers,
-Paul.

[Lambolica]

I'll put another tick for adrenalins.

Shot at 2007-07-06
Cheers
Simon

[pauljones1976]

What rim sizes (diameter) are we talking about here?
-Paul.

[myne]

For example, two tyres of the same traction and hardness rating can behave very differently - one may corner extremely well but stop poorly while the other may do the opposite.

I have no idea if the toyos and bridgestones I had were the same rating, but for the same price, the bridgestones had WAY better cornering and the toyos had heaps better braking performance. The toyos also had very similar performance in the wet and dry.

6 of one, half a dozen of the other :/