ZZS construction

[Mucus72]

Hi all,

I will start this post by telling you that I am not a tyre expert. I ha e used a set of ZZS tyres on my 420R since I assembled it last year. My car has now just done 3000 miles. 

My car has quite a lot of negative camber, and is primarily used on track. I had a tour to Scotland last week and set off with legal tyres, but half way around Scotland realised that my inside edges on the front were really wearing out fast. 

My assumption on excessive wear is either massive long stretches of motorway to get up there from middle England (with mainly the inside edges in contact with asphalt) or the fact that many of the Scottish roads travelled on were a very rough grade (but grippy) surface. 

By day 4 of 7 I received advice on here to buy new tyres on here from BMTR, and a day later had them fitted whilst up there. Great service from them (£100 plus vat a tyre) and Pre 3 pm. next day delivery for £25. Also kwikfit were ace. 

I told them that I wanted to keep my single edge worn tyres and try and kill them off on another track day. 

Now here's the point of my story. I was told by the manager that I wasn't taking them anywhere. He showed me the construction and the amount of rubber left on the edge of the tyres. It was really quite scary. I assumed that there would be some sort of carcasse beneath the tread, but no. The kwikfit guy poked his finger (I kid you not) through the tyre at its thinnest point. 

Beyond the tread there is NOTHING left. 

Here's a picture of one of the tyres : 

[David Brown]

Have you had the tracking checked, could be too much toe in?

[Smiffy555]

This is the problem with running a track set up on the road, plus it makes the car very 'twitchy' at the front.

Good service from BMTR, I've used them and they are a very helpful bunch.

 

[John Vine]

The kwikfit guy poked his finger (I kid you not) through the tyre at its thinnest point. Beyond the tread there is NOTHING left. 

My, that is scary!  I suggest you ask Avon for their comments -- and CC too if the tyre came with the kit.

The wedge-shaped wear pattern looks like a more severe version of my R400D CR500 fronts after 9000+ miles of mostly road use. 

Have you increased the neg camber for the track?  IIRC, the standard front setting is -1° 20' +/- 15'.  My R400D was  -1° 48' when last measured.

Agree with post #2 that it could (also) be a tracking issue.

JV

[ScottR400D]

Nothing unusual there. Look at any diagram showing the construction of a radial tyre, there's only one layer of ply in that area and the sidewall. Extra plies support the bead and tread. 

You can see the casing fabric in your picture; you've worn them prematurely, maybe by unsuitable  toe/camber and just left them too long.

Look in the bottom of the grooves in most radials, there's very little rubber and you can often see the fabric grinning through. Once the tread's gone you're soon running on fabric.  

 I'm running 0 toe and just under 2 per side camber. CR500s on the road are wearing quite evenly. I have ZZRs for TDs. I swapped them on the rims after 3 days to even out the shoulder wear. I think they'll do maybe 7 TDs.