New Tires - vibration

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Jun 13, 2016
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97
Location
AZ
Hi All

2019 Audi Q5. Replaced original tires at 39k. Went with Michelin primary tour a/s, installed at Costco.
As soon as I hopped in the car and got up to speed, I feel a vibration. Felt in the accelerator, steering wheel, overall chassis.

I've had out of balance tires before, and always felt it via a wobble in the steering wheel. This is just a low pitch harmonic vibration from 30+ mph. There is no steering wheel "wobble" - just a vibration.

Any ideas? It definitely doesnt seem right. Does this sound like it may still be a balancing issue, or could there be something else I should investigate first before I take it back?
 
Out of balance OR tire out of round.
If its in "balance" but out of round (so you're basically saying a bad new tire?), are they going to know this on the balancing machine, or are they going to balance them say everything is fine?
 
If its in "balance" but out of round (so you're basically saying a bad new tire?), are they going to know this on the balancing machine, or are they going to balance them say everything is fine?
Two different things. Out of round tires can only be detected using a machine with a road force balance feature....unless it is horrific.

With that said, our local Costcos here seem to have extreme difficulty with balancing tires. I think it has to do with the Coats balancers and their not-so-idiotproof mounting setup.
 
I've written on this before. I worked in a tire shop in the late 1960's. We had transitioned from the old standard bubble balancer to a spin balancer and had a dial indicator mounted on it. This was steel wheel years that were pretty true if not damaged. We viewed a tire with over a 0.030 out of round as 'suspect'. It was balanced and if the customer complained of a vibration, we would then use our tire truer to cut down the high spot and then check and rebalance as needed. They call that 'shaving' today. We had more problems with tire separations in those days with the new Goodyear Polyglas and Firestone 500 tires. We rejected too many of those right from the factory. Today, I have a shop that the owner has picked up an old truing machine and the shop manager is the fella that has done a couple tires for me. I like to start with a pretty true and round new tire.
 
I've written on this before. I worked in a tire shop in the late 1960's. We had transitioned from the old standard bubble balancer to a spin balancer and had a dial indicator mounted on it. This was steel wheel years that were pretty true if not damaged. We viewed a tire with over a 0.030 out of round as 'suspect'. It was balanced and if the customer complained of a vibration, we would then use our tire truer to cut down the high spot and then check and rebalance as needed. They call that 'shaving' today. We had more problems with tire separations in those days with the new Goodyear Polyglas and Firestone 500 tires. We rejected too many of those right from the factory. Today, I have a shop that the owner has picked up an old truing machine and the shop manager is the fella that has done a couple tires for me. I like to start with a pretty true and round new tire.
We still have one shop in Louisville that still does the shaving method...If needed..
 
Balancing machines need to be recalibrated sometime. I suspect many shops never verify their equipment. An out of round tire could be the issue. You could balance a square tire, but the ride would still suck. Remounting a suspect tire might correct the issue. It may not have seated properly.
 
Balancing machines need to be recalibrated sometime. I suspect many shops never verify their equipment. An out of round tire could be the issue. You could balance a square tire, but the ride would still suck. Remounting a suspect tire might correct the issue. It may not have seated properly.
Also the person doing the job needs to be trained to do it right...
 
Here's what I know about tire truing (shaving):

When it comes to tires, the term "Out-of-Round" is used a lot and it's almost correct. The industry term is "Uniformity" and also includes differences in stiffness. In the tire factory are $1M machines that measure uniformity - TUG machines (Tire Uniformity Grader) - and the shortcomings for this machine are that the measuring wheel is only 30" in diameter (the road is flat!), and it does it at slow speed.

Tires behave differently at high speeds than they do at low speeds and the correlation is only fair between the 2. Also, the measuring wheel diameter means that the machine measures over a smaller cross section, so you can get false positives (tires that are bad that measure good) and false negatives (tires that are good, but measure bad).

So why don't tire manufacturers measure tires for uniformity in line at high speeds? Because it is somewhat dangerous, and because they have figured out that low slow speed uniformity values will yield low high speed uniformity values, so it is only a matter of time before the problem is fixed.

Hunter Engineering has produced a somewhat affordable machine (just over $10,000), that also measures uniformity, albeit via the loaded runout method. They use the term "RoadForce". It's shortcomings are the slow speed (again!) and an even smaller measuring wheel - meaning even worse false negatives and false positives.

Tire truing only cures one aspect of uniformity. It doesn't address the difference in stiffness. At the time truing machines were introduced, TUG machines were the only other machines available to deal with the "Out-of-Round" problem. That means that tire truing wasn't 100% effective, so the truing machines fell out of favor.

But since the introduction of Hunter's RoadForce machines, we now have a better way to deal with the problem.
 
Here's what I know about tire truing (shaving):

When it comes to tires, the term "Out-of-Round" is used a lot and it's almost correct. The industry term is "Uniformity" and also includes differences in stiffness. In the tire factory are $1M machines that measure uniformity - TUG machines (Tire Uniformity Grader) - and the shortcomings for this machine are that the measuring wheel is only 30" in diameter (the road is flat!), and it does it at slow speed.

Tires behave differently at high speeds than they do at low speeds and the correlation is only fair between the 2. Also, the measuring wheel diameter means that the machine measures over a smaller cross section, so you can get false positives (tires that are bad that measure good) and false negatives (tires that are good, but measure bad).

So why don't tire manufacturers measure tires for uniformity in line at high speeds? Because it is somewhat dangerous, and because they have figured out that low slow speed uniformity values will yield low high speed uniformity values, so it is only a matter of time before the problem is fixed.

Hunter Engineering has produced a somewhat affordable machine (just over $10,000), that also measures uniformity, albeit via the loaded runout method. They use the term "RoadForce". It's shortcomings are the slow speed (again!) and an even smaller measuring wheel - meaning even worse false negatives and false positives.

Tire truing only cures one aspect of uniformity. It doesn't address the difference in stiffness. At the time truing machines were introduced, TUG machines were the only other machines available to deal with the "Out-of-Round" problem. That means that tire truing wasn't 100% effective, so the truing machines fell out of favor.

But since the introduction of Hunter's RoadForce machines, we now have a better way to deal with the problem.
and again the person using it need to be trained at using it...and be willing to spend some time to do the job right such as resetting the tire on the rim to fully correct the balance and get pound values less that 12...
 
Hi All

2019 Audi Q5. Replaced original tires at 39k. Went with Michelin primary tour a/s, installed at Costco.
As soon as I hopped in the car and got up to speed, I feel a vibration. Felt in the accelerator, steering wheel, overall chassis.

I've had out of balance tires before, and always felt it via a wobble in the steering wheel. This is just a low pitch harmonic vibration from 30+ mph. There is no steering wheel "wobble" - just a vibration.

Any ideas? It definitely doesnt seem right. Does this sound like it may still be a balancing issue, or could there be something else I should investigate first before I take it back?
If it's on a rear wheel, you won't feel the wobble in the wheel, but still feel the vibration.

Take it back, get them to re-balance.
 
Get a vibration analysis app, and a gps app on your phone, and drive true 60 mph. Figure out the exact type of vibration you’re feeling. Notionally it will solely be a ~14Hz tire related one, but could be something else too.

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Update: Took it back and they said I had a slight bent wheel on the front left. I guess maybe it was on the rear before and we never noticed, and after the new tires were on and it was put on the front its now noticeable.

I guess now to find somewhere to repair it and get it back into round. These 20" Black Optic wheels aren't cheap...
 
Update: Took it back and they said I had a slight bent wheel on the front left. I guess maybe it was on the rear before and we never noticed, and after the new tires were on and it was put on the front its now noticeable.

I guess now to find somewhere to repair it and get it back into round. These 20" Black Optic wheels aren't cheap...
I would get a second opinion.
 
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