XAS FF tyre wear

[miked]

I know these are soft tyres with lots of grip but I dont think I can afford the wear rate.

I fitted these a couple of years ago after talking with Steveww. They have been great for ride quality and grip. I think I have done about 4.5k miles (maybe a bit more) and they are wearing/worn out on the outside edges. I had a good look around them today.

MOT due next month

tred from out to in.

Front left 0 to 5 mm.
Front right 2 to 6 mm
Rear left 1 to 2 mm
Rear right 2 to 4.5 mm

My track is right front and rear (adjustable rear bones). Front camber has been at 3/8 degree neg at ride height about 10mm below book (from front bone horizontal).
Steve, are you still on your first set? How are yours wearing. Are they wearing on the outside edges?

I dont consider myself to be hard driver. Wife is usually in!
Went on one track day but is was wet. I am bit confused with the wear rate on the ouside edges. Is this the nature of the car in the bends with the 80 profile tyres. I had a set of SP 10's (I think). They covered about 8k with even wear and as I recall were about 5mm when I sold them.

Anybody else got these on. I have been as bit distracted/fooled by other jobs and seeing the side patern. It was only when I left the lock on the car and saw the front left that I clocked the wear and then started with the gauge. Have I been around to many traffic islands. It looks that way from the wear! I am not that experienced at this so my be talking a bit of b*llocks here!


Mike

[stuartgb100]

Mike,

When I get a chance I'll look at mine and report back, but off the top of my head they've been on for 2+ years and 5k miles.

I run standard camber at the front and negative at the rear.

Had been on my list to do a front/rear swop around this Summer.
That, and to sort out an understeer problem,

Regards,
Stuart.

[miked]

Stuart,

Thanks, I got caught out. I know I should have checked with a gauge. They look so good from the side. Spent lots of time on all other items, never dreamed they would have shifted so quick.

Whichever way the cat jumps I need some tyres. Will stick with the 80 profile even if I spend a lot less money. XAS are now over the ? ton. What shall I fit. Heard good things about Uniroyal rallies.

thanks Mike

[ill_will]

Sounds like you could run more (negative) camber at the front. I *think* (although someone please correct me if i'm wrong) that this should improve front end grip during cornering (and thus push the balance more towards oversteer) at the expense of a slight increase in straight line nervousness.

On one of my cars i scrubbed the outer edges of the front tyres quite badly understeering on roundabouts in the wet. Increasing the front camber made the balance more neutral. Straight line changes weren't that noticable.

will

[miked]

Will,

How much negative did you put on your front?


Mike

[cliveyboy]

The Dunlop SP10s on my sprint wear nicely.
But on my Alfa I changed tyre brand and the car just ate them. Full tread across tyre but no tread (almost canvas) on inner edges.
Checked suspension all OK
Went back to usual tyres and normal wear resumed.
Sometimes it is just the grade of tyre

Clive

[rgh0]

Mike

The wear you describe is identical to the type of wear I see on the Yoko A032R I use on my Elan on the track. I get about a 1000 track miles from a set to get to the same level of wear.

The modern XAS FF are a track compound and construction the only real difference to a modern road legal track tyre is the higher profile and retro tread pattern. So it does not surprise me the nature of wear and the 5000 mile life on the road

I use about 1/2 a degree neg both front and rear so your suspension camber sounds about right to. You could try a little more neg camber at the front to test its affect on tyre wear and handling - I cannot do it as there are limits to neggy allowed in our historic racing class.

cheers
Rohan

[miked]

Thanks for replies. Makes me happier.

I wil put some more negative camber on the front.

Re: SP 10's. I have used these before the XAS and they were pretty good. Only thing I thought was that they seemed to need some more pressure to firm the side wall strength. Then you loose some ride quality. When the XAS went on they natuarally had good side wall. Anything out there with a bit more side strength as SP10 wont break the bank. I think I should also stick with 155 for road use. Any thoughts on dropping the profile to 70. The 80's did feel right on the SP10's I used to have.

Sorry if i am digging up a subject that had been discussed before but when you look back a lot of the tyres have changed.

PS Those Dunlop SP Aquajet (remakes) are no good (in my opionion). I had them on about 5 years ago from that special vintage tyre place. Sent them all back. Side walls like a shopping bag. I know little about tyres but they were cronic, tucking over at 30mph on country bends. At the time I talked to Matties who had taken them off cars. When you felt the side wall it was no wonder. Maybe I had a bad batch?

Mike

[rgh0]

I think going to lower profiles in modern sticky road legal track tyres is the right way to go and gives you better handling - The 175 / 60 x 13 i use work very well and give my elan handling as good if not better than an Elise / Exige with the similar tyres they come with as standard these days

The downside is the smaller diameter which is a problem if you do a lot of highway crusing but not a problem for me as the lower grearing is perfect for track use and a 8000 rom engine.

To use the 13 inch 60 series tyres on the road you need a 3.55 diff and / or a five speed - which is how my plus 2 130S /5 is set up fro road use

70 profile tyres are better from a handling perspective than 80 series in general but I dont know any that come in modern sticky compounds and construction. An 80 profile XAS FF will be better than any of the 70 profile tyres know about.

regards
Rohan

regards
Rohan

[steveww]

Not sure how many miles the XAS FF on my S4 have done now. The Elan did not get a lot of use last year as the summer was rather wet.

The outside edge of the front tyres has worn down and have have swapped front to back to even out the wear. I will most likely only get this summer out of them before they need replacement. Mind you I do drive like I stole it and I have done a few track days

I know they are bloody expensive but they are so good. Quality was never cheap. As I used to run a 911 RS were a new set of boots cost over a grand I think the XAS FF for the Lotus are quite cheap. Those 4 palm sized patches of contact are the only thing that keep you on the road. Like brakes, tyres are an area I never scrimp on.

[miked]

Thanks for further replies.

I was just talking to the tyre guy and he said about going to 70 profile and go up a size to 165 to retain approx' rolling circumference and trye road patch. I had not actually thought of going to road legal sticky modern tyres (even though XAS were sticky). Was just looking to spec' up on the SP10 theme somewhat. Would modern sticky not wear mega' fast too!

He reckoned some ?40 odd Bridgestones would be better as decsribed than the 155 x 80 SP 10's.

My problem is I am buiding a second car for track use. This is the one with the extra input. Whilst I apprecaite what you say Steve about quality and agree, I dont really drive balls out on the road. It is not likely that I will put the road car near a track (again) due to it's condition and paint job etc. My wife comes with me and I have the odd blast. Decent safety and a bit more life span is what I am after. I think the XAS are probably wasted for the way I drive on the road (95% of the time) if you know what I mean. Sound like I am being tight but we do use the car a lot and do the picnic bit etc. Perhaps I am

Mike

[ill_will]

Mike,

I used about 2.5 degrees negative, but it was on an integrale not Elan and the settings are almost certainly not comparable. Perhaps go up in quarter point increments?

You could try increasing the settings and then taking it for an enthusiastic drive in the dry - you might be able to feel which edge of the tyres is hotter/colder when you stop, which should let you know how much you're using each bit of the tyre. Ideally you are aiming for even tyre temps, I believe, which seems logical as this would seem to indicate even use and thus even wear.

good luck with the changes

will

[billwill]

Mike

The wear you describe is identical to the type of wear I see on the Yoko A032R I use on my Elan on the track. I get about a 1000 track miles from a set to get to the same level of wear.

The modern XAS FF are a track compound and construction the only real difference to a modern road legal track tyre is the higher profile and retro tread pattern. So it does not surprise me the nature of wear and the 5000 mile life on the road

I use about 1/2 a degree neg both front and rear so your suspension camber sounds about right to. You could try a little more neg camber at the front to test its affect on tyre wear and handling - I cannot do it as there are limits to neggy allowed in our historic racing class.

cheers
Rohan

? How do you change camber on an Elan ?

[CBUEB1771]

? How do you change camber on an Elan ?

Rotting of the front crossmember adds neggy over time. More seriously I assume that the lads who talk of setting camber have installed the adjustable front and/or rear control arms. These are available from all the usual suspects: TTR, Spyder, etc. Otherwise camber and caster are fixed as you suggest.

[miked]

Yes, I will need top adjustable bones for more neg' camber. At the moment I have only filed the top bone holes slightly. I believe I could get (perhaps) another 1/4 to 3/8 degree on the right but unfortunately the bones on the left and/or chassis are different as I had to file the left to just synchronise the camber each side at ride height. You will be suprised when you check.

The rear is not the same each side either, more negative on the right. I dont know whether it is a spyder thing.

Funny how all the tolerances do this.


Mike