Took the two fronts to the Yoko dealer and he spun them up and had a good look at them. He said the treads weren't separating, but they are both running out, and he's not happy with them. He checked the wheels as well, but the tyres are the problem. They were MY17 not '15 too, so they are still under warranty. Problem is they came with the car and I have no proof of purchase, when or where etc etc. So looks like up for 4 new ones full price. Interestingly he said they would have been like this from new, it's not caused by misuse or damage. Be interesting to see if the rears are same - bets on they are!

I should add that he spent at least 1/2 hour with me and re-balanced them both - and didn't charge me anything, even though I offered and was happy to pay for his time. So I know who will be getting my business.

Did he skim the tyre treads rather than fiddle with weights?

No, but I’d indicated that I would be replacing them. I’ve got to have full trust in tyres - probably due to many years on sports bikes, never compromised on them. It did take out a lot of the vibrations. Only problem is no stock in Australia until September.

Lots of Motorsport people (for example) skim or shave tyres that are mass produced and have imperfections, if you need to add an inordinate amount of weight to balance the tyre...then, it is logical to remove heavy spots from the tread...

Hope they do a 4 for 3 deal when these tyres are in stock....got a set a few years ago - luckily all good and no problems with them so far.

Although, I had it a bit easier. Mate made up a rig consisting of a rear trailing arm, a fan belt, an old fridge motor and a wooden base to hold it together. Turned fast enough to polish but slow enough so you didn't have to constantly worry about sticking your fingers in the spokes...

That rig had part number AEG163rimjob