Bad rotor(s) giving symptoms of an out of balance wheel(s)?

[SilvererSHO]

You say you KNOW you have a bad rotor? DEAL WITH THAT! You will have to eventually anyway, may as well eliminate it from the equation.

There is also a consensus that tire/wheels affect ride quality. That's the free option since this only became prevalent after you switched wheels.

You also asked how could brakes when not applied affect wheel rotation. Remember the pads only disengage from the rotor by a few centimeters, not inches. ANY movement off center CAN affect the rotating mass. The question becomes is it enough for you to feel it? I would say ALL of our cars do something that we DONT notice. Good or bad from as simple as turn signal not working to an engine misfire. Doesn't mean its not happening we just haven't noticed it.

If I read correctly, I think you said you are running 18" wheels? I may be wrong that is a NOT a factory size the SHO. Only 19" and/or 20" So best believe a non OEM size be it width OR diameter CAN affect rotational balance. And if tire installer balanced wheel as 18", 19" or 20". Sounds impossible but a simple oversight, MAYBE!

Also, you keep asking the same question. Almost like you are waiting to hear a silver bullet and AHA moment. There MAY not be. Possibilities are numerous. Try the easy and simple first.

Your solution that cost you nothing is to reinstall your summer tires. Then repair rotors/brakes. Oh just because a tire is new doesn't mean it is without defect. A used tire was used and replaced for a reason!

I do have bad rotors just like probably half the people running 10-12 SHO's have bad rotors too.  I'm waiting 'till after Christmas to upgrade to a 13+ brake setup so why would I waste my time or money doing that when the brakes work fine and I have plenty of pad left?  I never had this problem 'till I changed wheels and tires.

Never said anything about "ride quality" and as far as that goes it should be better with the 18" rubber vs. the 20" rubber so I don't understand your point.  It's a vibration issue.

The pads do not disengage the rotors by a "few centimeters" on any car that I am aware of.  Technically they don't disengage hardly at all.

Your fourth paragraph makes no sense.  Are you aware how a tire is balanced?  And did you miss the part where I said they've already been balanced twice?

Yes, I asked if a bad rotor could throw the balance off and you're the only person that claimed it could. Now after reading this post, I have to be honest with you, you give me no reason to believe you at all because you seem to be unaware how brakes work and tires are balanced.

I am NOT installing my summer tires when it's cold out.  Why would I chance wrecking $800 worth of rubber?  Did you read the two links I posted?  And how is this a "solution"?  There's a reason I put all seasons on the car for the winter.

First, most people (especially "high performance" cars) don't knowingly drive on bad rotors! If a problem is discovered it is addressed hopefully sooner as opposed to later. You said you knowingly are driving on I believe you said cracked rotors! Very few if any reputable shops will install old rotors with new pads? So if you did that yourself for the sake of time and money for a later upgrade, then deal with the consequences of that decision that MAY surface. And your brakes apparently may not be working fine. Because you feeling vibration!

You never stated unless I missed it and I may have, that you intend to do a brake "UPGRADE" next year! If missed it and I may have, then a blonde moment by me. I APOLOGIZE! So the help that is offered is only as good as the information that is given. With that, I as well as others have suggested put the other tires back on and see. I suggested try them a few miles. Someone else said a few hours. And that within itself should not "destroy" them as you say. If driving on your "GOOD $800" tires for 20 miles or 2 hours destroys them then you have other issues with your car. I as well as others have stated wheels and/or tires as possibilities. Maybe you bought a car you couldn't afford?

The ride quality I was speaking of was the vibration. Vibration in the drive train or wheels affects what? RIDE QUALITY! Otherwise you wouldn't be here asking about a vibration that you "FEEL"! As for tire size, will an 18" ride "better" than 20"? I don't know. But you acknowledge that it will ride different! Which is why I said a non OEM size can affect things.

Personal attack? If YOU understood how a tire is balanced, you would know measurements of rim width and tire diameter are input into the spin balancer! Tire is then spun. I also said it could have been an oversight and MAYBE someone input wrong number. We're human and prone to mistakes.

With this, I will bow out of this discussion. It is becoming personal and if I "REACT" again as I should NOT have this time, it will get worse. So moderators and fellow members, forgive my tone.

But apparently you too (EXPLETIVE) novice to understand how your car works. Are too (EXPLETIVE) stubborn to try what has been suggested (reinstall "GOOD" tires). Too (EXPLETIVE) arrogant to receive input or suggestions from ALL members. SO go drive your (EXPLETIVE) car until the (EXPLETIVE) vibration rattles your (EXPLETIVE) teeth out! And you only have 6 post on this forum?

Now, go watch this (EXPLETIVE) video and (EXPLETIVE) LEARN how brakes work. Simply put, there is a (EXPLETIVE) clamping action and a (EXPLETIVE) releasing action that takes place.

https://www.youtube.com/watch?v=Mmls5foCor0

You don't get it do you?  It's almost like you've read half of what I've posted and drawn conclusions or made up stuff out of thin air altogether.  Nowhere did I say cracked rotors and nowhere did I say I've done any brake work.  I also assume you still haven't read the links I provided about driving on summer performance tires in the cold weather.  Yup, I know how to balance a tire dude.  I worked at a tire shop when I was in school and did plenty of them.  The reason you enter the width, diameter and offset is so the machine can calculate how much weight is needed.  And even if you screwed that up any competent shop will spin them again after the weights are put on to see if it's fully balanced.  And even if you don't enter anything into the machine zero is still zero as far as balance is concerned so it's damn near impossible to screw up if you spin it both before and after adding weights.  Oh, and I see you missed AGAIN where I stated I had them balanced again just last Friday and they balanced fine.  6 posts?  You can't get that right either I see.  And as far as how brake calipers work you seem about as ignorant as can be on that subject.  It's right there in your post.  You said: "Remember the pads only disengage from the rotor by a few centimeters" Well congratulations, that's the most ignorant statement I've ever seen posted here from anyone.  Your last two paragraphs and your comment about me buying a car I can't afford just prove that I'm dealing with a man-child here anyways.  One or more on every forum on the internet I guess.  Good to know for future conversations here.

[SHOdded]

One video on belt separation
! No longer available

but there are many others to peruse

[SilvererSHO]

One video on belt separation
! No longer available

but there are many others to peruse

I looked both tires over good last night when I swapped them and nothing stood out at all.  The guys at the other tire shop last Friday didn't see anything either.  I talked to the shop I bought the tires from and told them what's going on and they told me they'd mount a new tire in place of the one I think is bad even if they can't find anything wrong so hopefully that will take care of it.  And if it's not that one, well then I guess I'm stuck trying to swap out the other tires with the one I took off which will fix the issue through process of elimination I guess but that will suck to have to do it that way.   

[SHOdded]

Fingers crossed the fix is in in one shot!

[glock-coma]

Have you tried switching the tires/wheels front to back?
Maybe something on the back of one wheel causing it not to mount flat on the hub.

[sholxgt]

Am I the only one that enjoyed the fill in the blank expletive game?

Sounds like you're getting there by having the vibration move with your swap.  Just food for though...the problem could also be in the wheel.  I know it balance and looked straight, but you never know.  I don't think steelies are generally built to the highest quality levels.

[SilvererSHO]

Have you tried switching the tires/wheels front to back?
Maybe something on the back of one wheel causing it not to mount flat on the hub.

Yes.  Middle of the second page of this thread.

[SilvererSHO]

Am I the only one that enjoyed the fill in the blank expletive game?

Sounds like you're getting there by having the vibration move with your swap.  Just food for though...the problem could also be in the wheel.  I know it balance and looked straight, but you never know.  I don't think steelies are generally built to the highest quality levels.

I enjoyed the threat of where it may even get worse in his next post.  Oooooooooo....I'm just shaking with fear just knowing that's a possibility.

[derfdog15]

Going to throw a little fuel on the fire. If its a dry day, you CAN drive on summer tires in the cold, you just need to leave a bit more braking distance and not drive like a fool. I drove my mustang in VA from the start of the college semester through to thanksgiving, on summer tires, and had a few days where it was sub 40 degrees. No issues because I was extra cautious. For the sake of troubleshooting brakes vs. wheels/tires I would do this. Go out at a time with minimal traffic, and drive a few miles on the other wheels/tires and see how it goes.

A stuck caliper CAN cause vibration but it would also cause excessive heat, to the point that the caliper would begin to look as though the finish is rusted (as they can get hotter than the paint/coating tolerance). In some cases, if it gets hot enough, you may also find yourself with damage to the finish on your wheels (chrome bubbling).

If you have a brake issue, regardless of tires/wheels, I would correct that FIRST, as there is no point in chasing other issues when you have a "known bad" part on the car. This is my .02 but brakes and wheels/tires, as well as suspension are some of the biggest safety factors, and IMO should be kept in tip-top shape at all times, as they are your first line of defense.

[ZSHO]

Going to throw a little fuel on the fire. If its a dry day, you CAN drive on summer tires in the cold, you just need to leave a bit more braking distance and not drive like a fool. I drove my mustang in VA from the start of the college semester through to thanksgiving, on summer tires, and had a few days where it was sub 40 degrees. No issues because I was extra cautious. For the sake of troubleshooting brakes vs. wheels/tires I would do this. Go out at a time with minimal traffic, and drive a few miles on the other wheels/tires and see how it goes.

A stuck caliper CAN cause vibration but it would also cause excessive heat, to the point that the caliper would begin to look as though the finish is rusted (as they can get hotter than the paint/coating tolerance). In some cases, if it gets hot enough, you may also find yourself with damage to the finish on your wheels (chrome bubbling).

If you have a brake issue, regardless of tires/wheels, I would correct that FIRST, as there is no point in chasing other issues when you have a "known bad" part on the car. This is my .02 but brakes and wheels/tires, as well as suspension are some of the biggest safety factors, and IMO should be kept in tip-top shape at all times, as they are your first line of defense.

I agree with part of your insertion and would also try to rule out a sticky brake calliper.
The issue with a sticking brake calliper is that latter causes a massive wobble, the steering wheel is difficult to keep hold of and the wobble keeps going when you slow down, almost to a standstill!!
In the other hand Like all summer tires, they are not intended to be driven in near-freezing temperatures, through snow or on ice!
I think the owners manual specifically states that the OEM Eagle F1'S are not recommended/intended to be driven under 40 deg temps!.  Z

[LostnEye]

In the other hand Like all summer tires, they are not intended to be driven in near-freezing temperatures, through snow or on ice!
I think the owners manual specifically states that the OEM Eagle F1'S are not recommended/intended to be driven under 40 deg temps!.  Z

The manual does and you can expect less grip, shortened tread life, and sometimes sidewall cracking if using summer tires in the cold. However no one is recommending to run them all year, a swap and a quick cautious drive to verify it is not something with the new tires/wheels would not cause any issues.

[derfdog15]

In the other hand Like all summer tires, they are not intended to be driven in near-freezing temperatures, through snow or on ice!
I think the owners manual specifically states that the OEM Eagle F1'S are not recommended/intended to be driven under 40 deg temps!.  Z

The manual does and you can expect less grip, shortened tread life, and sometimes sidewall cracking if using summer tires in the cold. However no one is recommending to run them all year, a swap and a quick cautious drive to verify it is not something with the new tires/wheels would not cause any issues.

^^Exactly what I was getting at. Also why I said to do so when it dry, and preferably low traffic, so that there are ample precautions in place. You only need to drive a little bit to verify if the issue persists with the summer setup or not. If it does not, you know it is wheel/tire related to the winter setup. If it DOES, then it is more likely suspension/brake/steering related.

[92BlackGT]

oh man, i thought i was on SHOForum while reading this

[ZSHO]

oh man, i thought i was on SHOForum while reading this

I guess we try to keep any such riff-raff @ bay!.  Z

[SilvererSHO]

Well, I had the car in the original shop last week Tuesday where I bought the tires and they spun all the tires on the rims to match the high side of the rim with the low side of the tire.  Supposedly, the hole for the valve stem is punched in either the high side or the low side (don't remember) of the concentric run-out of the rim when manufactured.  Then, you're supposed to mount the tire accordingly using the 1/2" diameter painted on dot that's on the tire's sidewall.  Supposedly, a couple of my rims had the high or low spot of the run-out in an area other than the valve stem location so they re-mounted the tires accordingly.  It's better now but I still get a tiny bit of vibration in a certain MPH range.  I don't know if they're just blowing smoke up my ass to try and make an excuse for tire(s) that may be out of spec or not.  I don't know how there could be that much concentric run-out on a steel wheel to make a difference.  I'll probably just get them re-balanced again when I rotate them.  I'm kind of regretting getting steelies when I could have just got some 18" alloys for about the same price.

I really don't know how these threads take on a life of their own sometimes.  Talk about things getting overblown.  Maybe my subject title was mistaken for rotors that had chunks missing, stress cracks and 1/8" of runout.  My brakes are fine, I've looked at them myself.  Well over 50% left on the factory pads, no scoring, no cracking or discoloration on the rotors and they're well within spec.  They don't even have a ridge on them yet.  They have a slight warp to them that comes and goes.  Typical of a lot of cars on the road.  I'll live with that 'till I upgrade the brakes.  No, there is no fire and blue smoke coming from them as I drive down the freeway and no, the chrome isn't peeling off of my rims.  My teeth haven't rattled out either because it was always a minor vibration at certain speeds and a weird feeling at about 30 MPH.  I never said otherwise.  That's why I didn't think it was ply separation because it never got any worse as I put any miles on and the tread looks perfect.  I also don't understand the "no big deal" attitude about driving in the winter on summer tires.  Yes I could put them back on and drive down my rural road at a moderate speed but the risk of cracking the tires all up is just as great whether I put 5 miles or 50 miles on them if it's cold out.  And by cold I mean what we refer to cold in MN which sure isn't 50F.  Did anyone read the links about summer tires in the cold weather?  And I already had the summer tires/wheels on the car and replaced them with what I have now and that's exactly when the problem showed up.  So by putting them back on the car I'd find out what I already know within probably 99% certainty.  It's not happening with those tires and wheels because they just came off the car.


Anyways, rant over and thanks for the ideas and comments.  Most of them....