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The car sees a bit of track work so has some negative camber - more on the rear than the front, so the rears have proportionally more wear on the inside edges. Also naturally more overall wear on the rears than the fronts.

Will swapping the fronts with the rears to even out the tyre wear cause any problems other than having less front grip due to less remaining tread?

Less remaining tread=/= less grip.

Dann

I'd swap 'em. If the tyres are not directional, you should do them diagonally (I think?)

NitroDann wrote:Less remaining tread=/= less grip.

Dann

Fair comment Dann. Just trying to wear them out evenly.

My reply was basically saying that there is no concerns with swapping tyres regarding balanced grip so go for it.

Dann

bruce wrote:I'd swap 'em. If the tyres are not directional, you should do them diagonally (I think?)

I do not believe that it is recommended practice to diagonally rotate radial tyres, I rotate mine front to rear at 10,000 klm intervals.
Greg.

Gotcha Dann. Job done with the directional roadies which had been used for a few track days as well as plenty of road miles. Should mean they all wear out roughly at once, although not much left now on the inside edges of what were the rears.

bruce wrote:I'd swap 'em. If the tyres are not directional, you should do them diagonally (I think?)

The track tyres are not directional. I can see the sense in swapping them diagonally if I was doing it fairly regularly and starting with new tyres. How well would it work though starting with used R specs and with a car that mostly goes round anti-clockwise circuits?

Depends on the track really. Some corners will see more wear than others.

davekmoore wrote:

NitroDann wrote:Less remaining tread=/= less grip.

Dann

Fair comment Dann. Just trying to wear them out evenly.

you'll never wear them out evenly. but you'll slow down the inside wear issue.

So the track tyres are non directional. They are used ones, which is what I normally buy (they'll never be the fastest option but they're cheap and, unlike even very good road tyres they stay consistent for 10 laps instead of overheating after 3). There was no noticeable camber wear when I got them. The MX5 has 2 degrees of negative camber on the rear and one degree on the front. The rear tyres seem to have worn a great deal more on the inside edges than just 2 degrees would suggest. The fronts seem to have hardly any camber wear.

So putting the rears diagonally across to the fronts will help even out the camber wear and what seems to be a 75% rear:25% front wear differential.

But it will also mean the wear on the fronts will be at least 3 degrees the opposite way to how the tracking is set up.

Is there any problem with that?

If so should I just do the rears to the fronts without going diagonally and suck up the extra camber wear?

You must be spinning up the rears way too much to wear them out quicker than the fronts. I wear the fronts on my SE quicker than the rear.
Also, I have 1.2 degrees of camber, front and rear. I didn't see much of a point in increasing the rear any further than fronts would go.
I have noticed if I start sliding around, I do start cooking the insides of the rears though, comes with power.

As for rotating tyres around, never had an issue doing it. Didn't notice any impact on lap times either. I wouldn't say you would have lack of grip either, as it is only a marginal difference.
I just rotate tyres to get the maximum life out of them.
I also rotate them based on what tracks I will be doing, as I have a fair idea of which tyre will take the most punishment. ie Wakefield Park kills the front left tyre.

Have done it with asymmetric KU36's, which is easy as, as you can put them on any corner you want since they are non-directional.

Also have done it with directional Achilles 123S.
Could only do front to rear on these to keep them pointed the right way.
After a while I got the tyres flipped on the rims, so a left/right swap could be done, as you tend to hurt only your left tyres at Wakefield.

My main tip would simply be, look at how they are wearing, and put your best tyre on the one that will wear most, and worst on the one that will wear the least.