Hi Folks, Newby here, Inspired by a trip last month to Goodwood Festival of Speed with my two boys and recent retirement from the working world I just placed my order for the RCR GT40. Wife said I better find something to do to keep busy. What do you think of my solution? There is not a lot of information about tires here but there is some about the difficulty sourcing 15" tires. I have seen recommendations for 215-60-15 for front and 295-50-15 for rear. The RCR kit I am getting comes with the BRM pin drive wheels in 15x8 and 15x10. The 205 has a maximum rim width of 7.5". The 215 has a maximum rim width 7.5. The 225 has a maximum rim width of 8.0". The 235 has a maximum rim width of 8.5". And lastly the the 295 has a maximum rim width of 10.5". Maybe I am overthinking this, I was always told to match the tread width to the rim width. The 295-50-15 have a thread width of 10" and a diameter of 26.7" so these will fit on the 10" wheel perfectly. It seems best option for the front would be the 235-60-15 tires which have a 7.8 tread width and fit nicely on an 8.0" wheel, however they have a diameter of 26.1" just .6" smaller than the rears. Whereas the 225 has a diameter of 25.6" a full 1.1" smaller than the rear. 205 and 215 don't seem to be a good option given the BRM wheel is 8.0" and the max for those two sizes is 7.5". I should note that these dimension are for BFG TA Radials and all the numbers are from Tire Rack. I have been looking for tires for weeks and cant seem to find four from the same brand of any tire except BFG so I guess my question is what are people doing for front and rear tires on 15" wheels besides Avons? TYA
Newby with tire questions.
- Thread starter Mark Duquette
- Start date
You can't go wrong with Avons, if you can find them. I run 8.5 wide 15" rims on the front and 12 x 15" rims on the rear, shod with 215-60-15 at front and 295-50-15 at rear. Yes - in both cases that's wider than the recommended max rim width for each tyre, but they fit well and look great (IMHO), and my local tyre specialist, who fits a lot of tyres for race cars, had no qualms about fitting them.
I don't drive very far or much for that matter with my SPF MKII, so I mounted Indy Firestones, which sure look great. They seem to handle pretty well, no real issues but I really don't drive them hard either. The Firestones gave me additional ground clearence over the Avons, that came with the car. The Avon's did not fill the wheel openings to my liking, so the original aesthetic of the car was lost due to their lack of overall diameter. There are Goodyear vintage racing tires, 6.00-15 front and 7.00 or 8.00-15's for the rears but these are not street tires, not DOT approved but no reason why you couldn't use them. I am sure others will chime in with other recommendations. If you can't find the F/R sizes from the same manufacture there are always the Goodyear / Avon tire stencils and decals.
Attachments
Those sure do fill the wheel wells.
Go with the avons and suggest you do not fit 235 60 15 on the front as way too tall. I run the rim sizes you are getting with the avons you are being suggested to run and have done so for many years without issue.
Have RCRs got through UK IVA or SVA test now? As far as I was aware they were not designed with those road legality tests in mind. Might be wrong though. Or are you US based? Assumed UK as you were at Goodwood!
Have RCRs got through UK IVA or SVA test now? As far as I was aware they were not designed with those road legality tests in mind. Might be wrong though. Or are you US based? Assumed UK as you were at Goodwood!
Attachments
Lee Patterson
Supporter
You want to match overall height of the tire as well as width. I made an excel calculator to determine overall height for various tires sizes. Width is an "approximate" measure. For instance, I have a 215/60-15 on an 8" front rim and it is a perfect fit - no sidewall bulge at all. Personally, I like the look of the skinny rear and went 255/60-15s on 10" rears. Here is a screenshot of my excel file:
Lee Patterson
Supporter
And a paring chart to match fronts to rears. Hope it helps:
Thank You, nice chart, hope you don't mind I down loaded it.
By no means am I trying to cheap out on the tires I just cant bring myself to pay $3000.00 for them. I am US based, Goodwood was a Bucket list trip. They appear to be available at a place called Coker Tire. Also I am not positive because I cant find the story I read recently but because of the large amounts of carbon in the tire I would have to remove them and store them indoors because my garage gets below 32 in the winter and they are prone to cracking in sub freezing temps. Could be a different tire but thought it was the Avon's. Thanks for confirming the 235 is to tall.
Attachments
I understand your reluctance to pay $3000 for Avons. It's not heresy to buy a set of BFG TA's. That's what I've had on my SPF for many years now.
When I did trackdays I had a second set of tires. Are the TA's equal to Avons? Not at all, but they are perfectly adequate if you don't do stupid things with them. I have 225/60/15 and 295/50/15.
When I did trackdays I had a second set of tires. Are the TA's equal to Avons? Not at all, but they are perfectly adequate if you don't do stupid things with them. I have 225/60/15 and 295/50/15.
Lee Patterson
Supporter
I bought a split set of 215 and 255 Vitour Galaxy r1 tires. Paid about $150 a tire. They are rated to 130 mph which is plenty fast enough in my garage as build tires but frankly, they are a very quality piece and I will initially drive the car on them during set up. If and when NOVA starts making AVONs again, I may buy a set. But for now, Vitours it is.
https://www.prioritytire.com/by-brand/vitour-tires/galaxy-r1-radial-g-t?var-vitour=33285
https://www.prioritytire.com/by-brand/vitour-tires/galaxy-r1-radial-g-t?var-vitour=33285
When i first got my GTD on the road way back in 1992 it had BFG TAs and these were the go to tyre for replicas. Then the corvette club bought the rights/moulds and they became no longer available in the UK. After a while with no decent tyre option Avon came along and their tyres are in my experience way way better than the BFGs. For normal street driving i doubt it makes any difference (other than period looks and road surface noise) but if you choose to do a track day then the Avons are very much superior. I haver done maybe 20 plus track days at Goodwood alone so close to a thousand laps (guessing as never kept a record) plus i have taken part in many sprints at Goodwood ie competitive timed events. BFGs are seconds per lap slower plus they overheat quite quickly if going for it. The Avons don't overheat nearly as quickly and provide more grip as more rubber in contact with the road surface due to tread design and sizing. Once the BFGs overheat then its like driving on ice! Horrible. As an aside, if you want to scare yourself stupid, whack some sticky compound slicks on and really go for it! Makes you realise just how good the pro drivers at Goodwood are in the gt40s on Dunlop Post Historics L and M tyres (cross plies not radials) when they are so so quick in rain or shine.
You get what you pay for. And with a high value car like ours, why cut back on the one thing that keeps you fixed to the road? Same as putting in a 500 bhp motor and then using bicycle brakes!
PS never noticed any deterioration in the Avons due to air termparature going below zero. Never heard of that concern before.
You get what you pay for. And with a high value car like ours, why cut back on the one thing that keeps you fixed to the road? Same as putting in a 500 bhp motor and then using bicycle brakes!
PS never noticed any deterioration in the Avons due to air termparature going below zero. Never heard of that concern before.
In the UK your tyre rating has to match the potential top speed of the car it is fitted to. If you fit a tyre rated to a maximum of 130mph but your could run at 150mph then its not legal and you could get done. Neither of those top speeds are really practicable in the UK (but not impossible ahem!) on the road but that is not the law. If you have an accident sufficient for the police to want to throw the book at you then its just the excuse they need.
Dale Murray
Supporter
Go with the Avons. Perfect for your car. In case you didn't know, Avon had been bought out by Cooper who was then bought out by Goodyear. Goodyear accountants shut down Avon, and I think crippled the little town the factory supported.
But we got lucky and a new company came along with the molds, etc. called Nova Motorsport
novamotorsport.com
Buy them here: https://sascosports.com/
But we got lucky and a new company came along with the molds, etc. called Nova Motorsport
Nova Motorsport | A new global motorsport brand.
Nova Motorsport is a new global motorsport brand born with a mission to revolutionise the world of premium competition and specialist tyres.
novamotorsport.com
Buy them here: https://sascosports.com/
Just to add to the tyre/tire discussion, I have had a terrible job finding rear tyres for my GTD (here in the UK). I ruled out the Avons - far too expensive, and becoming very difficult to source. Avon has ceased to exist now, and is now marketed as Nova. However, I have found some road/race tyres which are just right for mine. Optimal rear tyres on mine are 265/50x15, but 275/50x15 are quite acceptable and the only size manufactured by this company. This is where things get interesting, as these tyres lack the required markings for sale in the UK for road use. Indeed they are sold as 'for track use only'. This is actually a bureaucratic nonsense, and derives from post-EU negotiations. However, by another quirk of UK regulations, these tyre markings do not apply to cars manaufactured before October 1990. My car is registered March 1990, so now has a set of these tyres fitted. They do look very neat. Speed ratings? Given low speed limits in the UK, my gearing is set for maximum acceleration and a relatively low top speed. I can just see PC Plod taking the gearbox to bits following a big crash to calculate top speed, even if they could work out the max revs of the engine (then in bits!).
Lots of good information, thanks everyone.
Michael
Supporter
FWIW, I just spoke to Sheila at SascoSports. The new CR6ZZ tires are not yet available from Nova Motorsports, they won't be available until maybe next spring. Just some old stock currently available and I didn't inquire which sizes they have.
She did suggest I contact Roger Krauss Racing, which I did. Roger said the new Nova factory in Portugal is still in the regulatory approval process, and only shipping five tires at a time, so progress is very slow. Roger also said the Nanking tires are available in GT sizes, and the folks who've bought them seem very pleased with them. Current prices for the Nankings are $449 front (215/60-15) and $569 rear (295/50-15), so $2036 per set less shipping...about $400 cheaper than the Avons.
She did suggest I contact Roger Krauss Racing, which I did. Roger said the new Nova factory in Portugal is still in the regulatory approval process, and only shipping five tires at a time, so progress is very slow. Roger also said the Nanking tires are available in GT sizes, and the folks who've bought them seem very pleased with them. Current prices for the Nankings are $449 front (215/60-15) and $569 rear (295/50-15), so $2036 per set less shipping...about $400 cheaper than the Avons.
Lee Patterson
Supporter
Did Roger provide any info on the Nanking tire? I know he was "developing" one but his website shows nothing on it.
Michael
Supporter
Well, development consisted of sending selected sizes of CR6ZZ tires to Nankang so they could duplicate them. The specs according to Roger mirror those of the Avons. They've been available for some time now.
Last edited:
Similar threads
