D16-YZ250F

Hey guys, im brand spankin new to the site because im trying to figure out some tires I seen and havent found much info on them, so where better to turn than a huge crowd of people? Long story short, i race scca local auto cross in street unlimited and I came across some new tires, but havent found any insight as to if there SCCA approved (which i assume they are since they advertise they raced scca with them) and if anyone has ever tried them? If so how did they work out? The tires in question are called "camber tires" sold at www.cambertire.com

anyone?

KIWI

It had to come...
I imagine the tires are directional, and the outside side wall will be taller than the inside therefore giving x degrees static negative camber.
Back in the good old days when regs disallowed any suspension adjustments we used to shave a little extra negative camber into the tires.
It will be interesting to see if these take off? and of course the compound of the tires will have a huge effect on the handling performance of any vehicle.

It will be very interesting to see how these work out, or is it just another gimick?

Kiwi

dirty19

iTrader: (1)

funny how old tricks come back as new technology

Johnny Mac

Yeah, it is an old trick used in old SCCA SS* classes where the rules didn't allow suspension or alignment tweaks. To get negative camber, the tires were shaved with some camber in them and it worked. However, by molding the tire in a truncated conical shape is new. I guess the question will come down to how good is such a small company as Scott's tire at coming up with a tough and durable compound that has a wide tread temperature range where the tire is near max traction and with good slip-angle building during cornering response.

D16-YZ250F

Thats funny its actually an old trick! Ive heard of shaving tires before in scca but never to add camber to the tire. I always thought it was kinda stupid to take a brand new tire and shave away the treads. In any case i did talk to them a little bit about the tires and apparently their tires are made by M&H, which I also looked into and it appears they seem to have good tires... again, ive never ran M&H tires either so again im without any first hand knowledge.

solo-x

Old trick. BFG R1s had camber molded into them too. I think I saw a Subaru at Nats in 2010 that was running the camber tires. Didn't do very well from what I remember, but I don't remember if the driver was any good.

97mm_EH3

BF Goodrich did this in the mid 70's for the Goodrich Radial series that they sponsored in IMSA. Needs more Google/Wilkipedia.

D16-YZ250F

Is there any scca rules saying they cant be used?

solo-x

Are you getting a set for free? Otherwise, I would stick with what is a known quantity. Bridgestone, Hankook, Dunlop and Toyo all make very good extreme performance street tires. If you really want to take the path less traveled, just read the SCCA rule book on tire limitations. I forget the number of sizes that are required, but if the number requirements are met and the tire is available before April 30th (unless they've changed the tire recently, that April bit is probably not a concern) then it can be used.

dirty19

iTrader: (1)

You got that right Johnny. Kinda pricey too if you check the website.
Makes one think about trying them though? If they were allowed....

Johnny Mac

There is a good reason why shaving tires makes sense. Firstly, some tire companies like Toyo with their RA-1 R-comp (a spec. tire in many racing series) molded the tire tread to 8/32" to provide usable wet traction. However, in the dry this tread depth isn't as responsive as say a 4/32" tread depth and even worse it can chunk/overheat.

Tire compounds are visco-elastic and during cornering and/or accelerating/decelerating they can generate lots of heat especially at high slip angles/ratios. These compounds are also very good thermal insulators so they can also hold in heat very well. During cornering, tread surface temperatures as measured with infrared sensors can exceed 300 deg. F peak and even higher internal temperatures can be reached. With larger tread depth, there in more heat generated in the tire due to more tire tread volume distortion but the external convective and wheel/air conductive cooling is roughly the same regardless of tread depth. Thus, the peak internal tire temperature will always be at least as high and almost always higher for a larger tread depth. Since the shear strength of tire compounds diminishes at higher temps, tread chunking becomes more likely with the larger tread depths. This is one reason most racers who use R-comps that are molded at 6 or 8/32" will shave them down to 4/32" or even 3/32".

Shaved tires are also more responsive than unshaved tires, which most drivers (who can notice these sorts of things) find better. In the case of Hoosier R6 or A6 tires, they are already molded to 4.5/32" or 9/64" and shaving is unnessary.

Andy Hollis

Not legal for SCCA Stock or Street Touring categories, as they don't meet the minimum # of available sizes rules. Maybe someday they will, but not now.

There is a huge thread on SCCAforums about it.

And for those that remember the BFG 226 Comp T/A R1 with the assymetric sidewall stiffeners, this new tire is built exactly backwards of that. At this point, there is no evidence that the "Camber Tire" actually works better in a motorsports setting.

D16-YZ250F

All i could find is that a certain tire WIDTH is limited in the STU class, 275 on a 2WD car and 245 on an AWD car. As for how they will perform better i read the review that was done by automobile magazine thats linked on there website and it did prove a lot better covering g's and some other things as well..... and yes they are a little on the pricey side but every little thing can help give the edge in racing.

beanbag

Wouldn't it be easier and cheaper to just cheat and bend your knuckles?

Andy Hollis

Street Touring
14.3 TIRES
Tires must meet the eligibility requirements of the Stock category with the following additional restrictions:

Stock
13.3 Tires
F. Each tire model must be sold in at least four rim diameters with a total of at least six sizes.