44 replies to this topic

[Beejay667]

If you go the used option for tyres make sure to check the manufacture date.

Which for those who aren't aware is a 4 number combo usually inside a smooth oval shaped section on the sidewall of the tyre for eg. 4212, which means made in the 42nd week of 2012. Pre 2000 tyres were coded differently, but we SHOULDN'T see any of those around.....but we do.

[Bill]

Ok took a chance on KU31's, They get fitted on Wednesday.

 

Thanks for the help everyone

[Morgan]

Beauty. You won't be disappoint!

[Ads]

From Bridgestone.com.au

http://www.bridgesto...r/care/age.aspx

Aged Tyres - Beware Your Spare

 

There is some evidence to suggest that aged tyres have an increased likelihood of failure due to exposure to the environment. Ideally tyres should be kept in a cool, dry environment out of direct sunlight and away from electric motors or other sources of ozone.

 

If these conditions are not met a tyre may have an increased chance of failure. It is for this reason that Bridgestone recommend including full size spare tyres in the rotation schedule.

 

How do I tell the age of a tyre?

 

All tyres are produced with a serial Tyre Identification Number (or serial TIN) that shows the date of manufacture of a tyre (See Figure 1&2 below). The last three digits (for tyres made pre 2000) or four digits (for post 2000 tyres) of the serial TIN indicate the week and year that the tyre was made. 

For example, Figure 1 below shows a tyre made in the 37th week of 1995 and Figure 2 shows a tyre made in the 12th week of 2004. 

 

Also a tyre made in the 1990's can be distinguished from a tyre made in the 1980's due to a triangular indentation after the last number which is not present on 1980's tyres. 

 

http://www.bridgesto...recare/Fig1.bmp

 

Figure 1: Serial code for 37th week of 1995

 

http://www.bridgesto...recare/Fig2.bmp

 

Figure 2: Serial code for 12th week of 2004

 

How old is too old?

 

This is a subject of much debate within the tyre industry and no tyre expert can tell exactly how long a tyre will last. However, on the results of experience many tyre companies, including Bridgestone, warrant their tyres against manufacturing and material defects for five years from the date of manufacture.

 

Based on their understanding a number of vehicle manufacturers are now advising against the use of tyres that are more than six years old due to the effects of ageing.

 

Tyre Ageing Mechanism

 

There are three main mechanisms of tyre ageing. 

 

The first involves rubber becoming more brittle. Sulphur is used to link rubber molecules together during vulcanisation with the application of heat and pressure, giving the rubber its useful elastic properties and strength. As the tyre absorbs energy in the form of light, heat or movement the tyre continues to vulcanise. This ongoing vulcanisation causes the rubber to become stiffer and more brittle. 

 

The second mechanism of tyre ageing is oxidation involving oxygen and ozone from the air compromising the strength and elasticity of the rubber and the integrity of the rubber to steel bond. Basically heat and oxygen cause cross linking between polymer chains (causing the rubber to harden) and scission of polymer chains (leading to reduced elasticity).

 

Thirdly, breakdown of the rubber to steel-belt bond will occur due to water permeating through a tyre and bonding with the brass plate coating on steel belts.  This causes the steel to rubber bond to weaken leading to reduced tyre strength and reduced heat resistance. If compressed air used for inflation is not completely dry, tyre strength will be affected over time. Even unused tyres will become more brittle, weaker and less elastic with exposure to water, air, heat and sunlight.

 

Warning signs

 

Regardless of their age tyres should be replaced if they show significant crazing or cracking in the tread grooves or sidewall (Figure 3&4) and or bulging of the tread face or sidewall.  

 

All tyres, especially unused spare tyres, should be inspected periodically to determine their suitability for service. If there is any question about a tyre's suitability please consult your local Bridgestone Tyre Centre expert. 

 

http://www.bridgesto...recare/Fig3.bmp

 

Figure 3: Sidewall cracking due to environmental exposure to oxygen, heat and sunlight.

 

http://www.bridgesto...recare/Fig4.bmp

 

Figure 4: Tread cracking due to environmental exposure to oxygen, heat and sunlight.

[SSIKness666]

Ok took a chance on KU31's, They get fitted on Wednesday.

 

Thanks for the help everyone

 

 

Cool! Let us know how they feel, prolly gona get em next time for sure.

[Morgan]

 

 

Cool! Let us know how they feel, prolly gona get em next time for sure.

 

Which one is it?

 

Probably or for sure?

[Hypnotic]

I know ku31s will be my next choice.

[SSIKness666]

 

Which one is it?

 

Probably or for sure?

 

 

For sure

[Samwise]

I'm enjoying the KU31's I just got.

Seriously, why aren't we partnered with Kumho?
They seem to be the main choice of tyre for Subyclub!

[Liberty]

Ha ha! I reckon. Sponsorship deal coming up!

[migoreng]

You will be happy with the grip in dry and wet. Mine are 8000km old, 215 45 17 size.

The ecsta logo is about 80% worn...

[Ads]

I tend to agree with this point for the most part but it doesn't really bother me too much.

 

I have not yet tried the Fed's although I have heard multiple good opinions in regards to them also.

 

I found the KU31's promoted understeer because of the wide, deep directional grooves.

It really pissed me off.

[Bill]

 

 

Cool! Let us know how they feel, prolly gona get em next time for sure.

Will do.

I'm going on a road trip to the snow this weekend so I will clock up about 1000km or so.

That should be enough to get a feel for them

[Jimbo]

Nice choice. I just got KU36's for the Focus. Hella sticky!

[Gen1Jack]

Michelin Pilot Sport 3's. Around $200 for 215/45/17s.

[Liberty]

I am in need of new tyres and have just been charged $165 each for Kumho KU31's and $290 each for Bridgestone Potenza's. Looks like I'm gonna give St George Tyres a visit.

[Samwise]

I am in need of new tyres and have just been charged $165 each for Kumho KU31's and $290 each for Bridgestone Potenza's. Looks like I'm gonna give St George Tyres a visit.

 

Yeah, they're good pricing!

[Liberty]

Just checked up, I can get the Kumho KU31's for just $140 per tyre from St George Tyres. Probably the best place to go to.

[neni]

Great thread, also sussing out ad08r ATM as well. I know they're new but has anyone had experience with the ad08?