Wheels go out of balance after a few days

[pidders]

Had a pair of Contis fitted to the front of my recently purchased 993 cabrio. They understeer like a bugger, but thats another story.

Been to a renouned Porsche specialist in Germany and they changed the steering dampers & shocks, checked for play in all the bushes etc & did a full 4 wheel allignment.

After a few days the wheels seemed to go out of balance. Kicks in around 65mph and smoothes out around 95mph. Not a real big vibe, but enough to piss me off. Went back and had them rebalanced (all 4) and all was fine for a few days. Not hit any pot holes or anything, but they've started wobbling again.

Feel like an idiot keep going back there, but just cant enjoy driving the car with it vibrating.

Any suggestions folks?

Cheers, J.

[CrashTD]

Were the balancing weights still in place or had they fallen off?

Edited by CrashTD on Monday 7th June 18:48

[pidders]

All the weights were still there. The second time they were balanced they were only out by 10g or so. I hoped it was just that the tyre needed to seat properly on the rim and settle in, but its gradually gone out again.

[CNHSS1]

the old trick was to fit tyres and drive car for a few miles and then balance them, ensured they were seated nicely. No one ever does it now as a matter of course, but i often get mine rebalanced after a couple of weeks anyway, often only slightly out with modern tyres and wheels but still nicer imho

[pidders]

Went to the tyre shop again yesterday and they said they og out of balance cos the tyre slips round on the rim....plausible I guess. I suppose it just takes a while for the tyre to stick in place, esp with the soapy lube they use to mount the thing.

[pidders]

Done that with the yellow crayon that the tyre fitter uses....so far so good.