Track Day Tyre Wear

[Windy Corner]

I have 15" Anthracites (195x45x15) on my 1.6 Roadsport SV, with about 3-4mm all round. I am booked into Keevil at the end of April, Cadwell in Spetember and hope to do a couple of more days, one airfield and one track perhaps.

 

The question for which the POBC would be appreciated is :-

 

I assume I will wreck my expensive CR500's in short order on track, so I guess it may be time to think about a second set of wheels and some tyres more suitable for trackdays.

 

How much wear should I allow for Keevil on the CR500's or should I get the trackday set for Keevil and save the CR500's for the road ??

 

Many Thanks in advance

 

Rik

 

Roadsport SV 1.6 Sigma 150

in Viper Blue here

[Neil_K]

It totally depends how you drive it, alone with climatic conditions etc etc. I've not been but I believe Keevil can be a fairly abrasive surface. Hopefully someone else will come along and confirm either way.

 

Given that there are a lot of variables, I'd suggest that they'd be on / close to the limit when you come to driving home. But it depends how many laps you do!

 

I'd opt for using decent tyres on the track. Afterall, that it where you will be using them to the full

 

Where am I?

[Grubbster]

Keevil can be a bit tough on tyres especially if you drive a bit beyond their limits If you drive smoothly and at 8 tenths then it wouldn't be so bad. As an indicator I'll measure my tread depths before and after the event I am doing there on Saturday. I am on R888s though so won't be true comparison but it'll be an interesting exercise anyway

 

Edit - yes it is abrasive, I'd keep the CR500's for the road and get a spare set of wheels with A048's or R888's for track use

 

Solent Se7ens Web!

 

Edited by - Grubbster on 2 Mar 2009 10:57:25

[Windy Corner]

Thanks for the comments,

 

Looks like that is the way to go, I will probably trailer it anyway but I was thinking if I trash the CR500s, then that is £400 + to be road legal again PLUS a set of Wheels & Tyres say £400 ish ??

 

Or if I accept that fact the the tyres would get trashed, I may as well spend the money on the spare set and not have to replace the CR500's (yet)

 

Does this sound right ???

 

Roadsport SV 1.6 Sigma 150

in Viper Blue here

[Mark Durrant]

Keevil is very hard on tyres as the surface is very abrasive. I would look to get a set of secondhand 13" rims with tyres and use whatever tyres they come with at Keevil. I would then replace the tyres with Toyo 888's 185/60 x 13 in medium compound and use these for trackdays.

 

Mark D

Comp Sec

 

[Windy Corner]

Thanks Mark,

 

Is the recomendation still for 6" fronts and 8" rears, ? or for only 150 bhp will this be a bit over-tyred at the back. I have seen some threads that mention 185x60x13 all round.

 

I was going for 185x60x13 as the diameter is marginally smaller than my 15" CR500's so won't have any wingstay issues.

 

Roadsport SV 1.6 Sigma 150

in Viper Blue here

[Mark Durrant]

Windy

 

185/60 all round on 6" rims will be adequate for your car

 

Mark D

Comp Sec

 

[Windy Corner]

Thanks

 

Roadsport SV 1.6 Sigma 150

in Viper Blue here

[Grubbster]

Just measured the tread depth on my track day R888s - new I believe they are 5mm, mine have done 1 dry trackday (Combe) probably around 90 miles (no road miles at all) and are currently measuring 4.6 on the front and 4.8 on the rears. I'll measure them again after Keevil this weekend and note the mileage I do there.

 

Edit - these are GG compound on 13" rims.

 

Edited again as I have only done 1 trackday on this set not 2.

 

Edited by - Grubbster on 8 Mar 2009 13:54:14

[Windy Corner]

Thanks for that, will await the outcome with interest

 

Have a good day on Saturday 😬

 

Rik

 

Roadsport SV 1.6 Sigma 150

in Viper Blue here

[millsn]

you will knacker them at keevil'

[Grubbster]

OK, update time. I have edited my previous post as I didn't use this set last time out at Keevil so they have only done 90 miles around Combe.

 

At Keevil yesterday they wore down a fair bit more - particularly the NSF. I did have a lot of understeer though so no real surprise! I have measured each tyre in 2 places, to see the difference between the inside edge and outside edge wear.

 

New they are 5.0mm deep all round.

 

After Castle Combe (90 miles in the dry):

INSIDE OUTSIDE

NSF 4.71 4.62

OSF 4.64 4.67

NSR 4.76 4.83

OSR 4.83 4.80

So the wear is averaging at about 0.34mm on the front and 0.2mm on the rear

 

 

After Keevil (100 track miles and 200 road miles)

INSIDE OUTSIDE

NSF 4.02 3.72

OSF 4.27 3.83

NSR 3.95 4.35

OSR 4.39 4.01

So the wear is averaging at about 0.7mm on the front and 0.63mm on the rear - certainly Keevil is much harder on tyres!

 

I can understand the outside edges of the fronts going (understeer) but the inside edge of the NSR seems a bit strange to me

 

 

Solent Se7ens Web!

 

Edited by - Grubbster on 8 Mar 2009 14:12:01

[Windy Corner]

Thanks for that Grubbster,

 

From reports, I had expected Keevil to be worse than what you measured

 

Definitely going to keep the CR500's fo the road then.

 

Thanks all

 

Roadsport SV 1.6 Sigma 150

in Viper Blue here

[Grubbster]

It was a revised layout yesterday and very gritty - my driving was far from smooth, playing around with oversteer and more than usual understeer so the tyres certainly had a good hammering!

 

Solent Se7ens Web!

[Grubbster]

If you want to see the revised layout you can work it out from this video taken by a friend in his Elsie on Saturday.

[pinkprincess]

Grubb, do you have a rear ARB? Might make a difference to your OSR wear

 

RW04FUN

RW08FUN

 

[Grubbster]

Not yet, I am waiting for a freestyle adjustable (I have one on the front on softest setting). But I am experimenting - so currently have M1 dampers all round, 130lb rear springs and 225lb fronts. The front feels a bit too stiff on the bumps at Keevil so I think I'll try something a bit less. Also need to get it flat floored - I have roughly set the ride height and rake but needs to be done properly.