What's the latest on radial tires for a 63 (H speed rating)?

[George J.]

Re: What's the latest on radial tires for a 63 (H speed rating)?

Longstone Tyres has them, and if I remember correctly, will ship to the USA. The 215/70 is about 300 euros. I guess that will be my choice in a few years, if nothing changes. Duke, or Michael, any estimate on life of the Avons (without track days)?

[Michael J.]

Re: What's the latest on radial tires for a 63 (H speed rating)?

I've had mine for 4 years, maybe 4000 miles. I don't track the car, just cruises and some highway driving to shows and judging. They still look new, on a light car without abuse and limited miles, they will last until the time factor takes over, not wear.

[Duke W.]

Re: What's the latest on radial tires for a 63 (H speed rating)?

The Avon CR6ZZ has a wear rating of 80 - same at the Yokohama A008s that I run on my '91 MR2. It goes through two sets of rear 225/60R-14s for every set of front 195/60R-14s, and I got about 11K miles on two sets of rears wearing them to the cord, which included a few track events. The new tread depth is 6/32". I have the same experience with the V-rated 205/60R-15 Toyo Proxes RA-1 on the Cosworth Vega. They have a wear rating of 40 (later changed to 100) and come with 8/32" tread depth.

So, based on the above and what Michael said I'd estimate the hard compound version of the CR6ZZ is good for 10-20K miles normal road driving on a vintage Corvette, including some sporty driving.

The spec sheet doesn't list the new tread depth, but it is probably somewhere between 6 and 8/32".

DOT legal racing tires typically provide maximum grip at a tread temperature of about 180-200F. You can't get them that hot in any kind of reasonable road driving, but even at normal driving tread temperatures they have WAAAAAAY more grip than any conventional road tire, especially the van tires that most guys have on vintage Corvettes.

Maximum grip will be obtained by running a little negative camber up front and hard bushings on the front anti-roll bar links to mitigate the C2's tendency to transition to oversteer at the limit, and if limit oversteer is still an issue, replace the OE 3/4" front bar with the 13/32" front bar used on late C3s.

Duke

[Michael J.]

Re: What's the latest on radial tires for a 63 (H speed rating)?

I will also add that I bought the Avons for how great the black walls look on a vintage Shelby Mustang, since they are really racing tires (tyres?), but nice to have them so well built, and able to hit high speeds without problems too.

BTW, here is a handy Tire Size comparison algorithm to use:

http://www.discounttiredirect.com/direct/infoTireMath.do

[Steve V.]

Re: What's the latest on radial tires for a 63 (H speed rating)?

[QUOTE=Duke Williams (22045);683623]...seems a lot of guys have trouble with tire sizes - both the correct numbers and proper format.

The H-rated Pirelli Scorpion STR is not available in size 205/75R-15. It IS available in a 215/70R-15 and the service description is 96H, so the proper full description is Pirelli Scorpion STR 215/70R-15 96H.

Dike,

I seem to be missing something. Tire Rack and the Pirelli websites both list a 205/70 but not a 215/70 in the STR type and no 205/75.

Steve

[Duke W.]

Re: What's the latest on radial tires for a 63 (H speed rating)?

Sorry, my mistake. I may have been looking at some old data in my files. As of now the only 15" Pirelli Scorpion STR listed at tirerack.com is 205/70R-15 96H.

Also, to everyone, don't confuse the Scorpion STR with the Scorpion ATR. The latter is a truck/off-road tire.

Duke