So originally I thought I had a dodgy tyre fitted when I last had them fitted, although to their defence they lasted 20k+ and weren't a budget brand.  I just thought the car was just loud on the motorway with tyre roar, but I then noticed that when on a perfectly flat road and going pretty slow I noticed a drone, like a "wom, wom, wom..." as if the tyre was an egg shape, not a circle.

I then discovered a significant flat spot. 

I now have a flat spot, on the same wheel, after another 15-20k... 

I am about to fill it with petrol and light a match...

I had something similar and it was down uneven wear of the tyre that gave it a wavy profile, so it would "slap" the road with every turn.  I thought it was a bearing on its way out from the noise, but turned out just to be the tyre.  I changed it over for a second hand one as a stop gap until I could get both done on the same axle at the same time and I think that one was never balanced properly and gave a vibration effect.  I was lucky that after a long motorway journey I got home as saw this - three quarters of it was good, but one part was nearly worn through to the steel reinforcement!  The new set have lasted 30k miles are still going well, so hang in there and hope the next set are better.  BTW, I use Michelin Primacy and apart from that one duff one they have all been fine.

 

 

I've recently being using Hankook Ventus V12 tyres

Its just so strange how a flat spot appears on that one wheel, in roughly the same place everytime. 

 

Have you tried rotating the wheels around to see if it is definitely the tyres that are the problem rather than tracking or alignment?

9 minutes ago, south_bound said:

Have you tried rotating the wheels around to see if it is definitely the tyres that are the problem rather than tracking or alignment?

I've not rotated them other than from front axle to the rear, to try and get as much out of them as I can.  

I had them new on the front from January 2016, moving them to the rears in March 2017. On the front, they wear fine across the pattern. So after maybe 20k+ and a year on the rear, the flat spot develops. So I've actually had a pretty good innings with them. 

Previous to that it was the original Michelins that came with the car I think. 

You say the issue is on the same wheel - do you mean the same wheel or the same corner of the car after wheels have been swapped front to rear?

That sort of wear can be caused by a duff shock absorber if it's the same corner of the car.  But if it's the same wheel it's more likely to be a fault with the wheel itself.

3 minutes ago, TomsFocus said:

You say the issue is on the same wheel - do you mean the same wheel or the same corner of the car after wheels have been swapped front to rear?

That sort of wear can be caused by a duff shock absorber if it's the same corner of the car.  But if it's the same wheel it's more likely to be a fault with the wheel itself.

The same corner... nearside rear. 

I'll look at replacing the shocks. They have done 5years+ 65k+ running on 18's... which I hate. 

Have you checked the wheel is running true? It could be that the brake disc on that corner is not sitting perfectly flat on the hub flange (I'm assuming your model has rear discs). A small discrepancy there would be magnified at the wheel circumference and it could also cause uneven braking on that wheel.

12 hours ago, mjt said:

Have you checked the wheel is running true? It could be that the brake disc on that corner is not sitting perfectly flat on the hub flange (I'm assuming your model has rear discs). A small discrepancy there would be magnified at the wheel circumference and it could also cause uneven braking on that wheel.

No, unfortunately I have the pre-war tech MK3 focus still with drums... 

Ford didn't deem the 1.6TDCi fast enough to need rear discs...  They're fine as long as you only brake once every half hour, any more than that and they fade pretty quickly on a windy B road!  

I wonder if the same applies though, drums can warp as they're horrific at dissipating heat.  I haven't seen or even heard this issue caused by that but that doesn't mean it's not possible.

On 6/8/2018 at 9:58 AM, TomsFocus said:

I wonder if the same applies though, drums can warp as they're horrific at dissipating heat

Good point. I've had cars with drums that were distorted, giving uneven braking.