phatgixer's SL55 AMG alloy/tyre upgrade problems

[phatgixer]

Taken the 20" wheels off as the conti tyres kept blowing out. horrible things.

[dazren]

Stunning photo in your profile. Were the tyres blowing out during normal high speed road use or when hooning it on track? Being mindful that similar tyres/alloys are fitted on the even heavier Brabus S-class saloons, What did Brabus suggest was causing the problem?

DAZ

PS - Do you want this thread moved to the Mercedes forum where it can act as a warning to anyone considering alloy/tyre upgrades?

>> Edited by dazren on Monday 16th August 21:39

[phatgixer]

dazren said:

Stunning photo in your profile. Were the tyres blowing out during normal high speed road use or when hooning it on track? Being mindful that similar tyres/alloys are fitted on the even heavier Brabus S-class saloons, What did Brabus suggest was causing the problem? DAZ PS - Do you want this thread moved to the Mercedes forum where it can act as a warning to anyone considering alloy/tyre upgrades? >> Edited by dazren on Monday 16th August 21:39

If it helps people not buy the terrible tyres, then please do.

Brabus say they have TuV tested the combo and they found no problems. Well I find it hard to agree. The trouble is that Conti are the only people who make the size (305/25 ZR20 rear and 255/30 ZR20 front). I want Pirelli or Michelin please.

Each time the tyres have blown I have been doing about 80-90mph on the road, and only one of the THREE (and one other that was checked and was on the verge of blowing) that have blown had been anywhere near a circuit.

The failure is always the same. The inner sidewall on the front fails catastrophically and opens up a foot long gash blowing out instantly. The only good thing is that the beads and other unaffected siewall are sturdy enough to keep the car reasonably in control.
That is 4 failures in less than 10,000 miles. There is some sort of heat build up problem due to the weight / sidewall depth / loading from offset that is causing this. I can not be the only one. The wheels and tyres cost over £6,000, so I am more than miffed. I have had absolutely no response from Continental.

One time the tyre blew the day after I had checked the pressures, so running for long periods underinflated is not the cause.

For clarity the tyres in question are 255/30 ZR20 Sport Contacts.

They don't grip that well either, but were reasonable at speed in the wet, otherwise they are nasty, nasty things...

[dazren]

Very poor. I'd be pushing for a refund of the cost of the alloys if the supplying dealer can't supply tyres that work.

There was a 640bhp Brabus at the last but one VMAX Bruntingthorpe session. Think the driver was a colleague of adamt's. I'll email him a link and find out if the driver of the car has suffered similar problems. I remember it had very large alloys to accomodate the huge brakes.

DAZ

[phatgixer]

dazren said:

Very poor. I'd be pushing for a refund of the cost of the alloys if the supplying dealer can't supply tyres that work. There was a 640bhp Brabus at the last but one VMAX Bruntingthorpe session. Think the driver was a colleague of adamt's. I'll email him a link and find out if the driver of the car has suffered similar problems. I remember it had very large alloys to accomodate the huge brakes. DAZ

They will be the same ones. Monoblock type IV (or VI, I dunno!).

My supplier is the one who is having a blanket of silence given to him from Conti. A bit too late to ask for my money back from him. The wheels are 15 months old now.

[phatgixer]

They did look nice though...

[dazren]

Look fantastic. The same as on the Bruntingthorpe car.

At this stage all you can do is put your concerns in writing to Brabus in Germany and ask what steps they are taking with the tyre manufacturers to make tyres that can cope with the weight and performance of the car.

DAZ

>> Edited by dazren on Thursday 19th August 18:20