7.0Ltrs of Love

so i made a post a while back after i just got these drag radial SS 335/25-20 tires mounted about how bad the car would be all over the road... after getting a new alignment and testing air pressures the swaying problem did improve but was still what i would consider wayy too much and unusual for these tires as ive owned MANY muscle cars and have ran these same tires on them with even more side wall and those cars never swayed like this....

ANYWAYS to the point.... i recently went to the drag strip for the first time since ive owned my ZR1 and cut a 10.7 @131 on a street night so not even a prepped trck....on my way home i noticed a sort of drive line vibration, felt in the seat and shifter which point to the rear of the car and this vibration would become more pronounced the faster i went above 80mph. Got home put the car on jack stands and put it in gear and the wheels were bouncing all over the place! Made an appointment at a local tire shop for a road force balance and they deemed the tires were so out of round they cnt balance them!!!

what can i do about this? these tires cost over $1k and i have maybe 1000 miles on them with 8 passes at the track. Do i call Mickey Thompson? Ive read there been many issues with these tires...

VTC_ZR1

Bought a set and had MAJOR issues balancing them, one was basically an oval and the other wasn't a helluva lot better. Ended up pulling them off and going with a dedicated set of drag wheels/tires and some nice true street rubber for the stock wheels. God how I missed being able to cruise at 70+ without getting an unwanted massage..

whatcop?

So what I've noticed is that they aren't out of round, but are rotating on the rim and knocking the balance off. Now whenever I have new ones mounted I have them mount them without lubing up the tire or rim. It helps a bit, but typically after a solid sticky launch they still spin a bit on the rim. Not sure if its Mickeys fault or the CCW they are mounted on.

Fifedogg

You should get a hold of MT. I've heard nothing but issues with the 20" and hearing of a few people getting free replacements from MT directly. Don't think they would be sending out replacements if there wasn't an issue...

hardtopz28

I spoke with Mike at mickey thompson they know it's a problem and he's saying about 60% of the tires have this issue and they should have a fix next spring. Just call them they will refund your money. I bought mine from jegs and they told me to call them and they will give the approval to refund the money and send them back.

7.0Ltrs of Love

That's what I was wondering. ..But the shop I brought them to to check the balance actually said the tires were out . .according to their roadforce machine ..How that would happen after one track day I don't know . ?

Do you think they just came so out of balance from spinning on the rim that whoever checked them out mistook that for being out of round ? Maybe try somewhere else ?

whatcop?

I would definitely go elsewhere and have them rebalance. I usually have to rebalance my drag radials a few times during their lifespan.

yellowzron

I had the same issue with a set of mickeys. I thought the tires were bad but it was all int he balancing because the firestone I went to had a kid, young man that could not figure out how to balance a set on such big rims. I am not sure if thats your issue but, thats the first thing I would check.

7.0Ltrs of Love

ya it was a younger kid maybe mid 20s doing it.... ill go to a shop i trust just its a 40 minute drive from where i live... its where i originally had these tires mounted when i first got them

7.0Ltrs of Love

Resurrecting this just to post a video I took of what I'm trying to describe.

https://youtu.be/5yuPdvgKfns

sjm115

i have owned many sets of MT's on other cars and they were always fine. I have the 20" MT's on my ZR1 and they are the worst tires I have ever had. They are so out of round it feel like my car is going to shake apart. It is miserable to drive. I am going to try to get my money back.

whatcop?

Now that's interesting to see

7.0Ltrs of Love

so today i brought my wheels and tires to another shop that is an all around auto repair shop and very local. this place had great reviews from ordinary people and the guy was one of the nicest most professional guys ive ever dealt with. he has a top of the line Hunter road force machine and he brought me in with him through the whole process of going over these tires... he first inspected them and thought there were many odd things like the fact the rim lip stuck out so far past the tire and the obvious issues... upon dismounting them he couldnt find any signs of belt shift or anything but he then felt the bead of the tire (the part that actually mounts and seals to the rim itself and he said they were rounded out as if i was spinning the tires on the rim... he pulled out many other used and new examples and showed me how their beads had a sharper "edge" to them. i had a new set i had ordered to be mounted which he pointed out they actually looked a bit wider than my current ones and even a hair taller... also the bead edge was sharper. he then proceeded with mounting the new tires and while doing so he pointed out the fact that when the bead sealed it was silent when usually there is a loud pop! he said that that may be due to the softer side wall OR maybe the steel cords in the bead are larger than they should be which COULD be the reason why these tires spin on the rim. anyways final results are the new set i had mounted actually have more side wall bulget than the old set whereas the rim lip actually has some sort of protection from scuffing! doesnt look odd anymore as if the tires werent seated. BUT one of these brand new tires he couldnt balance at all!!! he indexed it on the rim and the rim was straight but still it was so far out the hunter machine said it can not be balanced! so now i have to try and send back this brand new tire! ugh.... why does MT suck so bad with quality control???

Kryckter

I have the same problem on a set of 345/35/18 ET Street SS tires. Way too many weights to try and balance. You really feel it terrible on the street but when I had it on the dyno it was bad and you could see how terrible these tires were...

whatcop?

Just got some fresh MT 18s and thought this was interesting.

C5 Hardtop

Measure the tires to make sure they are within spec? Holy chit. So they can't trust their manufacturing vendor. NFW would I trust my life and those lives around me with those tires. A blowout can be deadly. Is there a note somewhere else asking for speed rating test results?

7.0Ltrs of Love

I also just got yet another fresh set (335-25-20) aftafter having to send back two tires due to not being able to be balanced on a hunter machine...noticed they are wider than my first set and the rim lip doesn't stick out further than the tire anymore... anyways my new set didn't come with those nifty mounting instructions!

Also can you clarify what it says on the instructions right where that glare is? Is it rubber cement? Is that something that is for only with use of tunes? Because there are no tubes for a 20" wheel that I know of.

whatcop?

I'll check for you later after work

whatcop?

Fifedogg

So the new versions have more of a "Rim Guard" now? I always hated how it left so much of the lip of the wheel unprotected.