295 50 VR 15 CR6ZZ tyre coming to the market

Malcolm

Supporter
As you may or may not be aware, for the last two years (following on from Andrew Fordyces GTD40 Car Club magazine article) I have been pushing Avon to make some tyres to suit the GT40 world.

Yesterday at AutoSport International I had another meeting with Trevor Swettenham and his department head Julian Baldwin and they have said they wish to know order numbers now for a 295 50 VR 15 CR6ZZ radial tyre.

With those with me yesterday we placed an order for 12 tyres (fronts and rears).

If enough tyres can be committed to, Julian Baldwin will press the button to manufacture the moulds this coming week with tyres available in the summer. It takes 3 months to make the moulds and then some time to check the tyres are good from it.

Either contact Avon direct on ++44 (0)1225 357694 asking for Brian Davies or Trevor Swettenham. Email is to [email protected] or you could pester Julian Baldwin with the main switch board number being ++44 (0)1225 357855.

If you are going to the AutoSport show please go and see the Avon stand and find Julian Baldwin there and pester him. The more he gets told to make these tyres the more chance he will press the button very very soon.

About the tyres themselves as most guys will not know them.

These tyres are E marked so are fully road legal and are of Radial construction so have a good sidewall strength. The tread pattern is of a 1960's race tyre pattern. The compound is fairly soft so these tyres grip and are great in the dry and in the wet these tyres have been reported as being better than the Dunlop Post Historic series (orginal GT40's race on these) and are actually quite good. But who drives their 40 in rain other than when they get caught out?

The speed rating is correct for gt40's so there is no need to worry about whether you are legal in that regard. VR ratings are good for 140 mph for two solid hours I beleive. Please correct me if I am wrong on that one.

The most successful user of these tyres is Andrew Fordyce who has 215 60 VR 15 on the front and 245 60 VR 15s on the rear of his car. He has used them on road and track as well as in competition through the GTD40 Car Club. He feels his times are as good as any he had before on other non road legal rubber if not slightly better.

On the narrower rear tyre Andrew reported being able to lap Goodwood in the mid 1 min 35 sec bracket with passengers. That is a good lap time and would be even for those on 17 inch rims running the superb Goodyear Eagle F1 tyres.

These tyres will be available internationally. They look the part, perform better than previous 15 inch tyres and are much much cheaper than 17 inch tyres, about 2/3 the price in the UK, although final prices have yet to be provided to me. The 245 60 15 tyre cost Andrew back in 2003 £146 plus vat.

If you can contact Avon direct please do so NOW or please indicate that you would be an interested user of the new size of tyre below and I will get the information to Avon directly. They are also looking to make a 275 60 VR 15 for the Cobra crowd as that is their ideal size. If you are a cobra person then please also pester Avon.

Avon are fully aware of my posting this thread and want feed back. The racing guys are all for it. We need to persuade the marketing and financial guys. Numbers of tyres will help in that regard.

The paper I prepared in late 2004 has sat on Trevor Swettenham's desk all year. Please don't let that cluttering of his desk be in vain!
 
I wonder,
When i read on the forum about theoreticle speeds of 200mph or plus
And i also see that there are people who are racing on the track

Don't they ever excess the speed of 140mph or do they all have 17'rims and tyres /ubbthreads/images/graemlins/confused.gif

Frank
 
Thank's Ron
I Know they won't explode
i thought it had something to do with the stiffness of the ring in the tyre so it won't
run of the rim by high speed's and the compound is different i gues
I'm also on the search for tyres so this topic has got my interest

Frank
 

Ron Earp

Admin
Ron, if you know those guys at Pantera Place or whichever is the big Pantera forum maybe we could have some links to each others' sites. I'm sure a lot of issues we all face are similar with respect to mechanics and consumables.

Ron
 
Have e-maied my order to AVON. What size fronts would be recommended? 215/60 front would seem a bit skinny compared to 295 rear
 

Malcolm

Supporter
The 215 60 15 is the only sensible choice as the 245 60 15 will trash inner wheel arches on a GTD (too wide and tall), don't know about other replicas. The 225 65 15 is too tall but actually has a smaller foot print over the 215 60. Don't ask me why but that is what the guys at Avon said. I have previously infomred them that a 235 50 15 would be a good front. No joy there yet.

The original GTD set up was for a 215 60 15 with a 265 50 15 rear. Those that put a wider front tyre on did find a better turn in, no question. I have booked in for 215 60 15 fronts as have the two others with me at the show.

The speed rating is based upon what a car COULD do! Our cars could sit at 140 mph for two hours. Where or why is beyond me but if it can do it then you need the right speed rating for the vehcle. Those guys with anything less than a V rating are open to issues if Mr Plod chooses to make a point of it or indeed their insurance companies if they wanted to wriggle on any claim. Had the owner declared the tyres in the insurance application? No, then change of spec for standard so no pay out???? You pays your money and takes your choice I guess.

Avon do offer a choice of compound, a soft and even softer! Andrew I belive was advised that the super soft would overheat very quickly on track use. Maybe use an even softer front and a soft rear? When push comes to shove I think I will asking about that as a solution. For general road use I doubt a 215 60 15 will be a problem.
 
Malcolm, very interested in a pair of 295 50 vr 15 tires. My question is what is availble for the front of our GT40's? I am running a 225 50 15.
Hope to hear from you soon, Cary
 

Malcolm

Supporter
Hi Cary

My post above yours suggests a 215 60 15. That is what I will be using. At your own discretion you could look at other manufacturers and compare compounds, treadwear ratings etc and use another brand, or maybe stick with your current tyre? Itis a shame they do not make an ideal front to match this good sized rear.
 

Ian Clark

Supporter
Hi Malcolm,

This is very good news. Several Cobra owners I know are running 295/50/15 on the back with no difficulties. Always in favour of more tire width whenever possible (snow excepted!).

I do have some reservations about 215/60/15 as the defacto front tyre size. It is bit on the skinny size. OK for Kate Moss and Stirling Moss (40years ago) but now we need some rubber on the road. At the end of the GT40 program, the JWA cars were running 10" wide front wheels and tire diameters close to 24.5".

Looking at the number of original cars that have been fitted with "Gulf flares" which they never came with, along with all the wide body replicas, why mess around with narrow fronts? The trend is obvious.

Since the fastest you can corner is limited to the maximum grip of the weakest tyre, putting anything less than the widest tyre on is giving away grip.

A 215/60/15 tyre is about 25.16" dia, on the upper limit of ok for these cars. CAV Canada runs 225/50/15 which come in at 23.93" dia, on the lower limit of ok. However, at 10mm wider, this is a big plus.

If there is the opportunity to suggest a front tyre size, why not something wider in a 50 series thereby keeping the the aspect ratio the same front and rear?

Certainly some guys will have get wider rims to take advantage of this, but are we ever going to get the chance again? Narrow tyres are not coming back into fashion:)

How about a 245/50/15? works out to 24.65" dia and will fit commonly available 8" wide wheels. 30mm wider puts almost 1.25" more rubber width on the road than a 215.

This seems to be as correct as possible and as such should have the broadest market appeal and longest product lifespan... 235/50/15 would be the narrowest on my wish list.

How many tire sizes will Avon tool up for? A 235f/275r/50/15 package would be great for regular width cars with 245f/295r/50/15 for the wide bodies. If it was only two sizes, the best combination for the world market would be: 235/50/15 front and 295/50/15 rear. These are sizes I believe manufacturers would sign on for as well...

Hello - CAV, ERA, GTNZ, MDA, RCR, RF, Superformance, Tornado etc. and all the kit projects being completed, let's make it worth Avon's while!

Cheers
 

Tim Kay

Lifetime Supporter
I am a little confused why the fuss here?

Hoosier currently sell 245/50zr/15 and 275/50zr/15 (stamped DOT). Soft compound, yes, therefore not great mileage but isn't it "smiles per mile" anyway.

What am I missing /ubbthreads/images/graemlins/banghead.gif
 

Malcolm

Supporter
The hoosiers are totally road illegal in Europe! Grippy tyre though. USA guys should not have an issue as DOT as you state.

A 245 50 15 used to be available in a Goodrich ZR1 but these trashed inner wheel liners of the GTD. Then I was told the corvette club got the rights to the tyre and it was no longer available. If you ran stiff suspension you could get away with it, just.

The suspension geometry of the GTD was designed around a 215 60 15 front and a 265 50 15 rear. I am a GTD owner and have been for 15 years. Clealry biased towards solving my own tyre issues first!!!!! /ubbthreads/images/graemlins/beerchug.gif

What tyre do the CAV's run at the front, size you have mentioned but not make or model or speed rating? Clearly you don't have your ideal front tyre either as you state it is just ok. I think we are in the same boat?

Please don't get me wrong here but I would not necessarily agree with you that wider is always better. Why don't all modern supercars run the 335 width tyres that can easily be bought nowadays? I think the trend is towards larger rim diametres and lower profile for control of the tyre to provide grip not just more contact patch. Control of the contact patch is also more important than just width.

Did you read all my posts above? The actual foot print of the 215 is greater than the 225 according to the Avon guys I have spoken to. I haven't seen this for myself in the flesh but consider then that if it is a correct statement then the 215 60 is likely to suit the CAV better than the 225 50. They say it is a quirk of the moulds! I hope they are right.

You also mention trying to keep aspect ratios the same front and rear. Again we shall have to disagree here. There is a tyre width difference, agreed. But I also want to have a physically similar height sidewall front and rear. To acheive this I need different aspect ratios. Your 225 50 concern of overall diameter proves my point. To me that is an elastic band wrapped around a rim! Most likley a good tyre though but to me would look wrong on a 40.

I will be feeding your comments back to Avon this week so hopefully this discussion will put pressure on them to make a suitable front to match this new rear tyre.
 

Ian Clark

Supporter
Hi Malcolm,

You raise good points, although accepting a tyre choice that suits one manufacturers design limitations does not serve the greater good. Doesn't it make sense to have rubber as close to original dimensions as possible?

I haven't seen the Avon tyres here and I'm sure they're good tyres. If the 215/60 is wider than the 225/50 it's an anomoly since there are formulas for calculating tyre sizes. The diameter is determind from the width and aspect ratio: Width in mm / 25.4 x aspect ratio x 2 + rim diameter.

235/50/15 is 235/25.4=9.251 x .5= 4.625 x 2 + 15= 24.251"

Useful formula:)

It doesn't look like the CAVs have any clearance issues front or rear by the way.

About the popularity of larger rims, it's all about bling, not performance.

Ok a front wheel drive econobox that was overloading the stock 70 series tyre will turn better on a 45 series tyre of the same diameter because of the shorter sidewall. Also the 45 series tire will run at higher inflation pressures and will have been designed for a higher static load rating to begin with. Probably better carcas/belt design too. So there's a lot of factors contributing.

Non of that has to do with a GT40 unless your kit is an Integra rebody (joking I hope!)

Same thing for 335 tires, they create a ton of packaging headaches, the weight and inflation pressures would ruin ride quality in a light weight car, so there's little justification for simply putting on the widest tyre possible. There has to be a reason.

The reason on the GT40 is originality, if it didn't matter we'd all be running 17 or 18" wheels by now. You'll also give up horsepower to spinning those larger heavier wheels.

We all have a vested intrest in these cars and the tyre issue is an important one going forward. Whatever input I can offer is rooted in creating the best long term market for these fabulous cars regardless of manufacturer.

With revisions of existing cars happening all the time and new cars to come, manufacturers are totally aware that the GT40 enthusiast is motivated by authenticty.

Cheers
 

Yuji

Lifetime Supporter
Malcom,
What would be the estimated price for a set, i.e. front and rear for GTD, in UK? Not sure being available in my area soon, but appreciate any info for my reference?
 

Ron Earp

Admin
Malcolm,

Ditto on the Hoosiers with them being larger than printed size. 225 Hoosiers are well known to be more like a 245 and 255 - I've measured them myself and found it hard to believe, but it was true. So, a 275 Hoosier that is available (what I was going to use and still will if RF uses 15 or 16" wheels) is considerably larger than a 275 "standard" road tire. Which, in my opinion, is a good thing!
 
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