Groove of Doom on A6 Hoosiers, anyone?

[Matt Leicester]

I just got around to pulling the race tires off our Miata (205/55-14 on 6" rims), and the fronts look like they are well on their way to an old school BFG Comp T/A R1 groove of doom. The outer "tread" groove is now at the outer edge of a maybe 3/4 inch wide shallow groove. The inner groove looks fine, as do both grooves on both rear tires. I haven't heard of anyone talking about this with the A6, and I don't remember the cause of it back on the R1s. I think more air pressure fixed it, but I don't remember for sure. The tire wear otherwise looks like it enjoys the pressure we ran (28.5 psi hot). The Kumho 710s haven't done it, and we ran them at 27 psi (I'm pretty sure... I should write these things down!)

I know we can flip the Hoosiers on the wheels, so that's what I'll do next time I mount them, but I was wondering if anyone has input on this? It's a lot of money for us to buy tires, and we really need to get a full season out of them (And no, I don't want to hear you Z06 folks complaining about YOUR tire costs, we for sure can't afford that!) This set has 24 runs at World Arena and 12 runs at Nationals for those interested.

Matt Leicester

[khammack]

I have had my A6s on all season and I'm not seeing this problem. I did flip them about mid season and I'm running preasures in the low 30s.

Ken

[PaulL]

I have over 100 runs on one of my sets, and they still look good across the tread face and appear to still have about 1/2 their tread left. Of course, they have hardened up into track compound rubber, now, but that's another issue! (285/30-18 on 10")

One odd wear pattern that I have seen on the A6es is an area of higher wear that occurs between the outer shoulder and the outer tread wear line.
This area between the shoulder and the tread wear line is about 4" across on my tires, and the oddly worn spot is roughly in the middle of that and is about 1" across.

It is basically just an area that is more worn down than the rest of the tire. If I deflate the tires or remove them from the wheel, it looks like a 1" wide flat spot/groove that goes all the way around the tire. It is also bluish in color, which indicates higher heat than other areas.

I'm surprised that the actual shoulders don't wear down before this area. It may have to do with the carcass design or with my car's camber and roll characteristics.

Maybe this is the same thing that you've got?

[Built-By-Bones]

Matt

as a high volume A6 user

We had this happen on one of the A6's we had at Nats. 6 runs, right front of the Mini, east course, Tuesday. The groove was approx 1" wide and we noticed it before the groove covered the entire circumference.

The tire had been heat cycled when ordered from Tire Rack, and I had scrubbed them on the Sunday test n tune. So they had two heatcyles with at least 48 hrs cooling each.

I took both fronts to Hoosier, and Jeff Speer could compare left front vs right front. He says they have seen this occur on about 1 in 100 tires in testing and there is no degradation in performance - I remain sceptical.

I wonder if you will get as much life from your A6's as you get from V710's. We are cording the A6's in about 40 runs (camber challenged Mini). If we flip the tires on the rim ( I always run the tire in the same direction so RF becomes LF or LR) we can get 80 or more runs as long as we put them on the rear for some of those runs.

This is a huge improvement over the S04/5's which would cord in less than 20 runs sometimes.

In comparison I can get over 100 runs from V710's. The last set had 52 runs and then I put 106 miles on them at Pueblo last friday before they were shot.

HTH

Grant

[lundgren]

You have to flip them if you don't have 2 degrees of neg camber. If you do, 100+ runs is no problem for most cars

[LoCore]

Jeff and I ran into some odd blistering after the ProSolo that we showed to Hoosier. It was occurring on the center side of the outside "tread ring".

They said they had seen this in some tires before, but that it wasn't a problem, and would probably go away after the next use. Sure enough, it did go away during the Sunday T&T.

I'll look at the two sets of Hoosiers I have for evidence of the ring.

Regarding flipping -- after how many runs should the tires be flipped? Flip just once, or after every "n" runs?

[Proxenus]

I'm not sure if there is a way to do this, but the issue was discussed on the evolution mailing list a while back. I think someone posted that a hoosier rep suggested flipping the tire or something and some kind of tire pressure change. They did whatever was suggested and had no problems.

It's in the archives there. If you can find it, ask on the list again and I'm sure someone will remember. Or call hoosier maybe.