Tyres

dreamchaser · Post by **dreamchaser** » Wed 15 Sep, 2010 09:05

My spare wheel tyre is at least 11 years old ( how long I have owned the car) but more than likely it is 19 years old as it is possibly the original. The other 4 tyres are 9 years old but have only covered about 8000 miles. In the handbook for my other BM they recommend 'tyre replacement after no more than 6 years, regardless of the actual wear of the tyres' Any comments welcomed.

Jet · Post by **Jet** » Wed 15 Sep, 2010 10:02

Check for cracking (wrinkles) in the grooves or sidewall, then make a note of the manufactured date via the Id Number, although you may have had them fitted 9yrs ago, they may have been at the suppliers depot for additional time, increasing its age. The ID will be either 3 digits for the 90`s and 4 digits from 2000 onwards indicating week and year.
Like most perishables, tyres also have a `best before end` date and a `throw away` date.
I would imagine both have expired and should be replaced.

felix · Post by **felix** » Wed 15 Sep, 2010 10:14

Given it's a space saver spare and tucked away out of UV exposure and limited to 50mph for a short distance I would be more worried that most people's spares are probably so low on pressure as to not be usable when called upon.

As for the main tyres checking for signs of dry rot and shifting belts is a good idea. As Jet stated look for signs of cracks between the tread blocks and if so keep an close eye on them. That said a friend's 2 year old Dunlops (per the tyre's date of manufacturing) are already showing cracks between the tread blocks. The tread surface should be smooth; if the surface is wavy or uneven you either have very worn shocks or the tyre is starting to delaminate internally. Normally you'll get plenty of warning of tyre delamination via noise and vibration.

My Goodyear GSD F1s still look like new and stick like the proverbial to a blanket so will stay on the car despite being 6 years old.

c_w · Post by **c_w** » Wed 15 Sep, 2010 12:06

As above, it's the UV light that kills tyres so the usage life is based on that. If it's hidden away out of UV then the life is extended hugely.

Stoertie · Post by **Stoertie** » Tue 12 Oct, 2010 08:04

It's not only the UV that killes the tires. The flexibiliser inside the rubber dissapear and the surface get hard. So you will loose more and more grip. The problem is, that this happend very slowly and you notice the differnence between new and old tires after changing the set.

I cast off my first Good Year Eagle set when it was 4 years old, because safe driving in wet condition was not possible anymore. My Bridgestone S-03 becomes slipery after 5-6 years... And our cars are stored in a closed garage most of the time.

Next year we will change to the Hankook RS-2... this tire has very much grip under dry conditions, but you should drive carefull in heavy rain.

Regards
Michael

Racing Tortoise · Post by **Racing Tortoise** » Tue 12 Oct, 2010 08:25

I don't like the sound of a tyre that requires care in heavy rain. Z1s are skittish enough in the wet (

) without the tyres making matters trickier.

Stoertie · Post by **Stoertie** » Tue 12 Oct, 2010 09:06

Racing Tortoise wrote:I don't like the sound of a tyre that requires care in heavy rain. Z1s are skittish enough in the wet ( ) without the tyres making matters trickier.

OK... maybe in Germany we have more and longer dry periods a year, so we need no rain specialists...

...I just tested the Hankook under dry conditions and it was fantastic. It gaves a very good feedback, was direct and very sportive and has a lot of grip (more then Bridgestone S-03)
I have not tested it in rain. With my semi-slicks ( Bridgestone RE-540S) it's possible to drive normal under wet condition, if there not too much water at the road, when you have rock pools (is it correct?) it's a little bit -let me say: "tricky"

In a comparative test of a german car journal together with semi-slicks from Bridgestone, Yokohama and others the Hankook declasses all and was absolutly the best in rain...

Regards
Michael