Tyre problems - advice please

[ian in lancs]

I'm after a bit of advice here please. I've had my tyres replaced on my Z4M with the correct Conti M3 fitment tyres. Cue wheel wobble at motorway speeds. I've had them rebalanced but noticed they both seemed to have a high spot - the tread moves up and down as it rotated on the machine. Anyway the quick run after rebalancing showed its no better - still wobbling / vibration at 70-80ish.

Talked with the dealer and they suggest sending them back to Conti under warranty. OK except that'll take up to 6 weeks and with no front tyres the killer suggestion is I buy replacements and get a refund from Conti if they agree they're defective. However, if they don't I'm left with 4 front tyres. Dealer wont budge. Where do I stand legally?

[Special K]

How long ago were these fitted or how many miles have you done on them ?

[ian in lancs]

3 weeks 400mls

[Hammer67]

Personally I would doubt that the tyres are the problem, much more likely to be distorted rims or the tyres are poorly seated on the bead seats.

[pist nbroke]

^^As above, a slight rim buckle or defect is exaggerated on the wheel balancer and can look like the tyre but v. rare.

[ian in lancs]

Rims OK; fine with old tyres and I've tried the car with alternative front wheels/tryes - so its not the car either.

[chryslerben]

You need to get the tyres road force balanced not just spun up on a normal balancing machine you will know the difference by the road force balancer will have a big drum which pushes against the tyre during balancing. If the tyres are the issue it will atleast give you a report to fight your corner with the warranty/dealer

[Jimmytno1]

Have you tried getting them balanced at a different tyre centre? Maybe the supplying centres balancer is out of calibration. As said above it's highly unlikely to be a faulty tyre.

[ian in lancs]

They have been balanced on two separate machines (eTyres van). I too am surprised the tyre could be at fault. I'm going to look at tyre seating although I doubt it and give them another chance to rebalance.

[chryslerben]

Jimmytno1 said:

As said above it's highly unlikely to be a faulty tyre.

You would be suprised we've returned a lot of n rated tyres before after road force balancing showed a tyre defect and these are supposed to be super duper porsche special compound/construction. Google it Ian and find your local fitter with this kit we have it but quite a journey from lancs lol

[wheels-inmotion]

They need to be balanced by mounting the wheel by the stud holes, not the centre hole, the centre hole is cosmetically central.

[Auburn852]

If you're sure the rims are okay with older or different tyres, then yes, it might be the tyres are off-balanced but this won't show on some machines.

Why not call the mfr directly?

Continental Tyre Group Ltd UK and Ireland
191 High Street
Yiewsley, West Drayton
Middlesex UB7 7XW
UK
Phone: [phone]

[Jimmytno1]

wheels-inmotion said:

They need to be balanced by mounting the wheel by the stud holes, not the centre hole, the centre hole is cosmetically central.

This would be my next step if the car came into my workshop.

[Jimmytno1]

chryslerben said:

You would be suprised we've returned a lot of n rated tyres before after road force balancing showed a tyre defect and these are supposed to be super duper porsche special compound/construction. Google it Ian
and find your local fitter with this kit we
have it but quite a journey from lancs lol

I can't recall ever having to return tyres to the manufacturer because of vibration/balancing issues, but then again, im not familiar with road force balancing! Will be googling it tonight, is it expensive kit to buy? Do you use it on every vehicle or just the higher end stuff?

[chryslerben]

Jimmytno1 said:

I can't recall ever having to return tyres to the manufacturer because of vibration/balancing issues, but then again, im not familiar with road force balancing! Will be googling it tonight, is it expensive kit to buy? Do you use it on every vehicle or just the higher end stuff?

Porsche is our main feed so we don't really have a lot of choice lol its not what I'd call cheap but worth it especially if your customers like to touch silly numbers at events/autobarns

[Frances The Mute]

9 times out of 10, vibration is down to poor fitting and balancing. Mobile fitters are notorious for this as they're equipment is rarely calibrated correctly when you consider the machine are fitted to the back of a van.

The dealer I use has the Hunter GSP9700 balancer with smart weight which measures radial force variation so they are able match the best wheel/tyre assembly to the location on the car to minimise feedback across the axle.

[ian in lancs]

Jimmytno1 said:

This would be my next step if the car came into my workshop.

on a beemer the centre hole aligns the wheel on the hub spigot. The bolts are just for fastening.

[Nick3point2]

wheels-inmotion said:

They need to be balanced by mounting the wheel by the stud holes, not the centre hole, the centre hole is cosmetically central.

bks! The centre hole as you put it is what alligns the wheel on the hub and takes all the radial load, the bolts just hold it on the hub and take axial load. I would go as far as to say it will be very well toleranced as the centre of the wheel relative to the outer diameter.

ETA whoopsies beaten to it.

[ian in lancs]

Getting them rebalanced by a local garagehas solved the problem.