Don't like these cracks on my Coopers

[Brid]

Cracks started to appear in the casing on my Cooper STT's, which I first noticed around 5000kms. They've now done about 45,000kms. Those in the photo are by no means the worst. Some are a lot larger. Strangely (to me at least) is that the front tyres don't seem to have many cracks. On these tyres, I've done very little off road (had to cancel a couple of trips), mainly bitumen and about 7% dirt roads.

I'm worried about water entry into the casing & rusting the belts, which could result in tread separation...something which was quite common with Coopers in Central Queensland about 12-15 years ago. I would have thought it would have long since been rectified, but I haven't had this happen with Wranglers, General Grabbers, Cooper STT's and ST's previously.

Any opinions?

[harlie]

To be able to give a mileage guarantee, Coopers use an absurdly hard compound. Unfortunately, the down side of such a hard rubber is they crack.

I did a 4wd course last year and the instructor advised against coopers for this reason. He had large chunks come off them while offroading with clients. Hard compounds also do not grip.

[flagg]

My STTs got cracks, and water got in. They delaminated at high way speeds. Happened to so many others as well.

By what happened to mine I consider cracks to be a safety issue and recomend you get new tires.

I'm choosing my words carefully to adhere to aulro name and shame policies, but lets just say I love my BFG KM/2s that i replaced the STTs with and won't be buying cooper any time soon.

[scarry]

I had a set of BFG A/T that did it as well,although they were six yrs old and had done around 70K.
BFG seem to harden with age as well.

[Bush65]

I had a set of Mickey Thompson MTZ (same construction as Cooper STT (Cooper own Mickey T)) and they cracked like that between the tread blocks on the first trip. At the time I put it down to running highway pressures on the Plenty Highway from Boulia to Jervois - I kept intending to let them down next stop, but forgot each time until Jervois.

I had a set of Cooper STT on another vehicle, that only did very easy country dirt road and a little bit of firm sand off road. They didn't crack at all there, but both fronts split on the shoulder exposing the steel belt.

Needless to say, neither are on my shopping list for tyres.

[Blknight.aus]

that tyre fails my road going inspection standard.

acceptable for farm work and sitting on crocks rims for recovery/emergancy use.

I'll take some pics of what comes next from my long overdue for replacement trailer tyres if you like and you can see the tread base seperating away from the belts in quite large chunks)

[sancho]

This seems like a common problem with Coopers thanks guys good to know

[Summiitt]

I had a set of Cooper ST on my puma, they had done about 15,000k and the front left failed a rego inspection due to sidewall cracks, upon investigation another 2 were the same, I took them back to the suppliers who offered to change the tyres for new ones...what you don't hear in the advertising is that the warrantee is based on a pro-rata of your tread wear,they hit me up for $115 per tyre, after admitting that these tyres had issues..! I wont be going down the coopers path again, very disappointed.

[Nomad9]

Hi Flagg,
I'm with you. Different lead up same outcome. The BFG's out of the US wear better than the ones out of Japan......... just a point worthy of note

[MLD]

Why do people whinge, bitch and moan about tread wear on a mud or AT tyre?

You bought it to be rough on the tyre, in rough conditions and expect long life of great grip and treat wear life. Tyres are a compromise and a consumable. If you buy mud tyres expect them to chip, tear, lose blocks and wear faster than a comparable road tyre.

The reality is rubber cures with age (hardens) and gets brittle with age. Until the manufacturers find the magic solution that meets treat wear and grip we will experience the shortcomings of a mud tyre.

my solution is buy a HT tyre and slide your way through a weekend of 4wd'ing.

If your post was meant to be a verbal on Cooper, you are at the end of a long line of dissatisfied customers.

i have BFG km2's and they are beaten, battered and ripped to shreds but never had a flat or rolled rim.

compromise

MLD