todinlaw

In addition to dropping a weight, my Tire guy tells me the rears were way off, He said I spun the tires on the rim was the only way to account for it as on one tire all weights were accounted for.

new toyo full tread 305/30/19's on OE 997-3 rims.

I went out this weekend on a new set of r888's and after about 4 runs I developed a hell of a high speed vibration. It turns out the tire rotated on the rim. I am hoping someone will tell me what I want to hear. I am hoping that becuase they were just mounted and had not been heated up that they may not have seated after mounting. I do plan on running a litter higher tire pressures also but has anyone found that newly mounted tires vs. ones that have been mounted for a while? I had Pirelli's on the rims before and they did not spin ever?

We did not remount them I just had them re balance I am hoping that they are good and seated in and It will not happen again. Hoping.

Larry Herman

Keep hoping. It is a recurrent problem, especially with heavy, high HP cars that brake well. Some wheel/tire combos are more succeptable than others. Only 2 known cures: 1) balance only the wheel so that it doesn't matter how much the tire turns or 2) use unscented Aquanet hair spray as a mounting lubricant to "stick" the tire to the wheel.

mdrums

This happened to my RA1's and my R888's. Next time have the edge of the rim scuffed up some so that the tire bead has something to bite into.

todinlaw

are we generally talking the rear tires under power and the wt of braking? I think the fronts were fine, I assume in a 911, the rears would be the problem? I will try hair spray next and then if necessary just balance the rim.

Jim Clark

You have mounting lubricant on the bead. Same thing happened to me and all we did was clean and scuff as said earlier. It hasn’t happened since, clean the rims with adhesive cleaner or acetone and scuff with a scotch pad, remount and balance

chris walrod

have this very thing happen on a set of V700's -- Only the fronts shifted since the 993 doesnt have enough power to spin the rears

Always mark the tire local to the valve stem to be able to visually troubleshoot this sort of problem early on.

KS-CS

Excellent tip!

mooty

my shop has mounted RA1, R888, R6, mpsc on oem, CCW, fikse, BBW wheels, all 18" and all on GT3's.
the tires do rotate, the max being 90 deg on the rim. however, i NEVER had vibration, if all the wts are accounted for. the only time i get vibration is if the weights fell off.. the wheel/tire were balanced together. they put high temp tape on the wts.

you might have them chk how true/balanced your wheels are?

multi21

Okay, I'm sure there is a logical explaination, but does the scented can of Aquanet not "stick" to the wheel properly?

mooty

^i dont know, as i dont use aquanet like larry does.

Bull

It happens with all tires, just more so on certain rims. Aquanet has been a help for many years.

Larry just doesn't like the scented Aquanet as it runs into his eyes when he sweats.

s997gt3

last year i bought a set of 18''ccw w/ the 888's and was told about the tire spin on the rims.

so john at ccw was doing some testing and the thing to do is to balance the tire as well as the rim. using a interior tire patch to act as a weight,so that any tire spin on the rim will not effect the balance,cause it will always be in balance no matter how much the tire spins on the rim,I've been told that race teams mount tires like this.
another thing is to try to find someone to dry mount or using the bare minimum lubricant .

this worked very well and never had a vibration problem.

by the way here is a option for you guys running 18'' rims a friend of mine ran these two weeks ago at thunderbolt in nj, and he said he was very happy with this set-up.
for 997 gt3

BF GOODRICH G FORCE R1 P265/35ZR18
P335/30ZR18--but remover rear spacer

BlueRiver86

Slick tires on race cars always move on the rim, but they pick up so much rubber inside the wheel over the course of a race that balance is usually shot anyway. I don't know of too many teams who go through the trouble of seriously countering tire spin.

APKhaos

You've just discovered a fact of life. Tires DO rotate on the rim in track applications.
Some wheels are better than others. I know a large group of our club guys had moved to Fikses, which were particularly problematic.

In Larry's defense, his fave brand of hairspray is popular around here too and for the same reason. It may be a meme, but that's the hot ticket for the well mounted tire among those determines to eradicate the dread slippage. The other thing to try is to have your tires mounted well before you use them. Using a freshly mounted tire with loads of still wet lube on the inside of the bead is obviously not going to help.

Dave in Chicago

And in low HP cars that brake well... I spin the fronts in one direction, the rears in the other. That persistent wheel vibration after that first track session is meant to remind you just how much fun you are having