TYres that failed

JenSE · Postby **JenSE** » Mon Jan 12, 2015 9:40 pm

Thought we should put these on record
Car was purchased in April 2013 with Stiletto Blue Streaks in the standard size 205x40x17
At a service on 9 January the mechanic suggested the rears needed to be replaced and a wheel alignment done.
When it went on the hoist for the wheel alignment the damage to the inside edge of the 2 front tyres became obvious. They had done 40k and the tread depth on the front was still legal. The tyre place suggested it was the position of the hoist but I suspect the cracking was probably evident all round. There was no cracking on the rear tyres

hks_kansei · Postby **hks_kansei** » Mon Jan 12, 2015 10:08 pm

I had the same model on a previous car, and they were given hell.

Not rotated for years, alignment way out, rubbed on gutters, etc.

used them until the fronts were showing cords, and never saw any cracks.

They're a sh*t tyre, but I wouldn;t say the cracking is normal.

MattR · Postby **MattR** » Mon Jan 12, 2015 10:30 pm

I would say they have hit a few gutters over time, also how long have the tyres been on the car?

project.r.racing · Postby **project.r.racing** » Tue Jan 13, 2015 7:41 am

As above. They have been dríven into a 25-50mm rise. It busts a single ply low profile sidewall easily.

I had something similar a year ago. The road guys were replacing the road surface. And the had shaved away about 40-50mm. And hadn't dropped in a bit of tarmac to soften the rise. I hit it at 40kph. With 215/35R18 tyres and 8kg front springs. The steering wheel jumped out of my hands from the hard bump.

Two weeks later, the car felt like I was dirving on is all the time. Front was wobbling. Had a look at the front tyres and the inside wall of both tyres had seperated.

lizard · Postby **lizard** » Tue Jan 13, 2015 8:50 am

No 1 question how old are they ??

I chuck any tyre thats older than 4 years reglardless

Magpie · Postby **Magpie** » Tue Jan 13, 2015 9:40 am

What is the DOT number on the sidewall? The first two digits indicate the calendar week of production and the next two the year of production.

If it is only 3 digits then it was produced before 2000.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11

Guran · Postby **Guran** » Tue Jan 13, 2015 12:27 pm

Photo 1 shows "0911" indicating the tyres were made week 9 in 2011. Not too old and 40,000km is very decent life for an MX-5 tyre (probably too good!) For the tyres to delaminate like they have, they might have been dríven at underinflated pressure for a while.