drivinhard

nothing new, but fun to document/measure. freshly mounted hoosiers 3 days before usage. 4 hot laps @ 10/10ths

rear tires (wheel spun inside in the direction of engine power, mark and valvestem were aligned)


front tires not as bad, but spun opposite direction (braking)

lot of movement for just ~4 laps

exracer28

I have been told hair spray while mounting helps. I just let mine slip

sperkins

Only one of my rears spun and it was about the same as yours. I did not mark the fronts.

66IISS

I've noticed a lot of spin with the larger tires (335) and auto-xing.

It may have something to do with my heavy right foot, I'm not sure...

fatbillybob

My marks are different. One weekend racing with AROSC and one weekend racing with SCCA...no movement.

I mount my own tires with hairspray...no slippage.

If I have problems which is almost never I mount with beadsealer.

RedLS1GTO

My 315x35x17 Kuhmo V710s turned about 20 degrees on the front and about 5-10 on the rear in a single weekend at VIR. It was pretty consistent on both sides. Brakes > Acceleration in my case.

redvetracr

I had that problem on my vintage racer (below), a trip to the glass bead cabinet to blast the tire bead and NO lube while mounting did the trick.

trackboss

Fatbillybob, whats the procedure for mounting with hairspray? I've mentioned it to my tire installer before and he said he would be willing to try it, but mentioned that hairspray gets really slick when water gets on it which may defeat the purpose. Also, how well does it allow the tire to slip on the rim when mounting? The last set of tires I had mounted were pirelli slicks and they were by far the most difficult tire to work with I have ever seen. The installer actually used brake cleaner and a lighter to get them to seat.

ZR1 MK

I do dry mounting too. Dry mounting and a clean bead means zero slip.

0Louis @ LG Motorsports

They slip 10% of what they do warm, vs cold. Much less slip when they are up to temperature and up to pressure.

The BBS' on the GT2 car are knurled.

c4cruiser

Some shops will use a lubricant made just for mounting tires that have to really stretch to get over the rim. Most just use soapy water. Once the water dries, that leaves the lubricant on the tire and the rim.

If a lubricant has to be used, then the rim and the tire bead should be wiped completely dry before inflation. Also with repeated tire mountings and use of lubricants, the wheel rim will have all sorts of tiny pieces of rubber stuck to it. That may not allow the tire bead surface to stick completely. The rim mounting surface should be completely cleaned prior to each tire mounting.

MattB

I had see this demonstrated for the first time this fall, a instructor with my NASA region showed me the slippage on his new tires on his Z06. He said that he was going to have the tire shop clean the beads before the next event.

The next event, virtually no slip. So, I figured that he had the beads cleaned. Well, No, he didn't do anything.

I'm leaning towards Louis's explanation: temps. I'd see where proper tire warm up before going full tilt, and ambient temps help.

fatbillybob

Interesting idea! I have never thought of this. I have no slip issues and think it is because of the hairspray mount. But maybe the reason for no slip is being a chicken making sure to get my tires warm before I spin out and look like an A$$ which I did once years ago right in front of the pits!


As to my mounting method I just use the cheapest target airasol hairspray I can get and spray the whole wheel as it spins on my machine. One coating and then mount the tire. I use no force because I got some slick tools to help me. I then air up the bead and let it dry.

I also have not considered getting the spray wet and what that would do. My race tires are always on dry and don't get wet. My rains I almost never get to use so I have not honestly noticed an issue. But I'll have to test wetting old dry spray and see what happens. I actually don't think an inflated bead will seap water so I don't think the spray residue will get wet again. If hairspray turns out to be a bad idea I can use bead sealer the same way as hair spray or soapy water and bead sealer is like glue/rubber cement. It makes for a more difficult bead breaking on dismount and a messier wheel to clean the seat on for new mount.

USA1C5

What does it matter if they do slip? Do they lose air when they slip? I can understand if they are balanced before they slip that they would be out of balance after they slip. I have heard that some don't bother to balance so when they slip, no problem with balance other than being out of balance to start with.

ZR1 MK

Its a balance issue.

Ive remember someone stating they dont balance, but thats ridiculous.

USA1C5

Yes, I can't see not balancing. I get a lot of vibration from all the pickup on the tires for the first few laps. I can't see running with all that vibration all the time. One would just have to be lucky and have a fairly well balanced set to start with, not to balance. Not much chance of that. I havn't tried to run an unbalanced set, but I would assume there would be a lot of vibration. Anyone out there tried running unbalanced wheel/tire setup?

sperkins

Poll:
http://forums.corvetteforum.com/auto...-balanced.html

ZR1 MK

I read your thread. Some of those guys running un-balanced are autocrossers and are null and void. As far as track guys, are we talking mud tractors or Corvettes. I find it hard to believe anyone is willing to run un-balanced. Looks like some people have much different standards.

FWIW
1) I had a balance done so that was so bad, the car was barely drivable. This, plus a few other reasons, prompted be to do my own mounting and balancing.
2) I threw a weight at Watkins once at 2 day event. Luckily it was on the 2nd half of the 2nd day. I just drove the car, but from 100-150 mph it felt real bad. Definitely a contributor to parts fatigue and parts failure.

WNeal

I've heard of tires slipping but had no idea it really did it until I marked mine at an event.
hard to believe it still holds air etc.

Webz

Trackboss,

I'd be interested in this technique. I have struggled trying to mount Hoosier R100's. There's got to be a trick or technique I am missing compared to mounting A6's or R6's.