Wacky handling

[dstev2000]

From new my MY08 L&K has always had a funny rear camber, it would always chew the inside edge of the rear tyres first. I always put it down to the heavy load in the boot thanks to my tools and other tat I lug around.

I drove the car round empty for a few weeks and noticed the rear wheels were somewhat splayed out and the steering wheel was ****ed so I took it for a 4 wheeel alignment.

These are the values as measured

Nearside rear camber

Before: -2.5 degrees

After: -1.6 degrees

Offside rear camber

Before: -1.9 degrees

After: 1.5 degrees

Front camber

Both -0.5 degrees unchanged

Rear toe

Both +0.10 degrees unchanged

Front nearside toe

Before -0.05 degrees

After +0.10 degrees

Front offside toe

Before +0.20 degrees

After +0.10 degrees

After the alignment the car seemed to be OK, it was a bit quieter on the motorway and it seemed to track nicely at decent m-way speeds.

It all went VERY pear shaped when the rear tyres were changed, the car now wanders badly on the motorway and seems to change direction in quite a sharp manner.

High speed corners as found on NSL dual carriageways lead to odd handling characteristics too - the back end of the car feels like its pulling outwards and away from the direction of travel, as if the back wants to go straight on while the fronts are steering. I have no confidence in the car at speeds upwards of 70mph.

I've been back to the place that did the alignment and they have told me the car is fine - twice! I have also had the car up in the air at Skoda to check for a popped rear suspension bush as i've had that before and the characteristics are similar but nothing untoward was found.

Finally, I have arrived at my question: WTF is going on????

Has the post alignment rear tyre change upset the geometry? seeing as the rear tyres were essentially wedge shaped due to the cocked camber would this mean the adjustments were incorrect?

And what to do now? another alignment somewhere else or could there be something that hasn't been thought about?

Any other comments are welcome also.

[wheels-inmotion]

Have you fitted Goodyear Assaymetrics?

[dstev2000]

No, they are Conti SP3s, nothing mind blowingly good as I do about 50,000 miles per annum. The old tyres were Avon ZV5s and they sucked big time, went 50p shaped in the end!. I have checked the basic stuff like correct direction and pressures etc. The handling literally went out of the window as soon as they were fitted.

[wheels-inmotion]

Since the trigger was the tyre fitment then it's wise to assume this is the reason the cars handling badly... Sorry to say sometimes the tyre and the car sometimes just don't work together.

[KenONeill]

AIUI you've changed the rear tyres, but not the fronts? That just might do it.

I agree with the resident expert that sometimes brand X just doesn't suit a particular make and model, but IME mixing makes front and rear can cause spooky handling on a car that would be ok up to the limit of grip on 4 brand X or brand Y.

[dstev2000]

Thanks guys.

I am going to change the fronts in the next few weeks, they are down to about 2mm across the tread so I'll stick a pair of SP3s on and see what happens. Despite peoples opinions of this tyre I have always got on well with it, can't say the same for the Avons though. Glad I got them for a snip.

I've mixed front and rear pairs countless times in the past but i've never experienced anything like this, I'll admit i've never mixed Avon fronts and Conti SP3 rears so it must just be this specific combination of tyres causing the problems. Very strange!

[_ZS_]

No, they are Conti SP3s

There's your problem right there. Woeful tyres for tramlining. Do yourself a favour and fit something else. Something like Bridgestone Turanza ER300 is an excellent tyre for your uses.

I know you say you "get on with them OK" but you probably don't realise what a decent tyre is really like - Avon are pure tripe, so in comparison the Contis probably do seem excellent.

[Wardy]

Are you able to try another set of wheels on the car? I'd just be curious about that as well, and it would be another variable that you could rule out.

Does sound very strange though!

Steve

[cheezemonkhai]

It's possibly worth putting the SP3 on the front and giving them a bit of a spin up or just taking sand paper to the rears to make sure the mould release compound has worn off.