i have cobra rear rotors on the 97 that i just bought, stock calipers with a relocator that brings the caliper out further, my problem is, the rear rotors are not spinning true, i guess its because the holes in them are all bigger, including the center bore, so as they spin they are a little out of round and make for a fantastic feeling when braking lol. what can i get to keep the rotors in the dead center of the rear hub and get rid of the shaking? do they make hubcentric rings that will allow me to put the rotor on true?

There is a guy on TCCOA that sells the adapter hubcentric rings... let me find his info... hmmm

Talk to ed.... http://forums.tccoa.com/showthread.php?t=37231 i just ordered from him for my relocation brackets but i am doing the hub swap so i dont have to worry about the extra spacer...

Get rings from Ed. He should sell them and the brackets together imho, as people really should use them...

I couldn't remember that guys name to save my life!

Wow. Those holes have to be really f'd up, because those studs aren't flexing with that hubcentric wheel. So long as the wheel has the hubcentric spacers installed.

Wow. Those holes have to be really f'd up, because those studs aren't flexing with that hubcentric wheel. So long as the wheel has the hubcentric spacers installed.
Most wheels are not hub centric for our cars.
This wouldn't matter anyways for the rotors as the wheel holds it in place, but it can slide still if it really wants. Rings are a good idea... :)

exactly the wheel holds the rotor on and if the rotor doesnt fit the hub like factory rotors then its not gonna spin true, so i need to get the rotor centered and need the rings to keep it centered. there isnt anything wrong with the wheel.

Understood. But the wheels on that car come with hubcentric rings. So if the wheel is tight, the studs can't flex to allow the rotor to move around, I would think. UNLESS the bolt pattern holes were drilled too large. Which must be the case. See what I mean? The rotor, hubcentric or not, cannot flex, unless the bolt pattern on the rotor was drilled with too large of holes.

He is refering to an up and down motion of the rotor, not a side to side.

What is up down? Depending on which how far the wheel is turned? Lol

He is refering to an up and down motion of the rotor, not a side to side.

When you have a circle the difference between moving up and down and side to side is nothing...

That being said Stack has wheels from Brand and they didn't come with any hub centrics...

When you have a circle the difference between moving up and down and side to side is nothing...

Right, that's why I LOL'd

That being said Stack has wheels from Brand and they didn't come with any hub centrics...

That's suprising, and now this makes sense. I was the very first to put a set on a markviii, and I got a set.

Jamie, if you don't have the teflon hubcentric rings for the wheels, call Brad. Otherwise you're still going to have a problem no matter what you do with that rotor!!

its not my wheel i have an issue with, my rear rotors are from a cobra, they are 11 inch rotors in the rear and they are horrible under braking, i need a ring to put inside the hub hole of the rotor, the cobra brakes have a larger hub hole. i guess the only people who can understand what i am talking about had to have put cobra rotors on their mark also. i need something that will keep the rear rotor true to the hub, i dont need anything for my wheels, the wheels roll true and the car drives perfect, its only under braking. the hubs are still stock mark VIII hubs.

its not my wheel i have an issue with, my rear rotors are from a cobra, they are 11 inch rotors in the rear and they are horrible under braking, i need a ring to put inside the hub hole of the rotor, the cobra brakes have a larger hub hole. i guess the only people who can understand what i am talking about had to have put cobra rotors on their mark also. i need something that will keep the rear rotor true to the hub, i dont need anything for my wheels, the wheels roll true and the car drives perfect, its only under braking.

Jamie, step back and read what I'm saying dude. Your wheels are cast from a mustang wheel JUST the same.

I completely understand the hub center on your mustang rotors are larger than your hub center on your hub.

Now, do you have plastic rings that sit inside the hub of your WHEEL? Because if you don't, they are not-hubcentric.

If they were, your rotor would not flex like it does, regardless what it came off of-unless the bolt pattern holes were drilled too large! (Not the bolt pattern drilled too large, but the actual HOLES that were drilled so that it would go on your car)

Got me bud??

If your WHEEL is hubcentric, and tight, you should not have a problem with your non-hubcentric rotors!! Because the studs COULD NOT FLEX if this were the case, making whether or not your rotor is hubcentric completely irrellevant!

well then obviously the holes that were drilled in the rotor to fit on the stock hub must be too big. i just got the car and havent even pulled the wheels yet i dont know what is behind them, i'm going off what the previous owner said, he said i need a ring to put in the hole of the rotor, from what i understand is my wheels are knock offs from brad with the mark VIII bolt pattern, not true mustang wheels so if the rim was produced to be on the mark VIII studs wouldnt it be true without any kind of ring?

Trust me Ponisviii... stack has the same rotors, and his vibrate the exact same way!!

i wrote to the guy i bought the car from so he can refresh my memory as to what i need, he told me when i picked it up, it was 16 degrees out, we were putting all kinds of extra parts in the trunk, my buddy and my brother in law were there, there was a lot going on so i didnt pay much attention to it, but he will tell me what i need, i also wrote to Ed on tccoa and he has rings to put a cobra rotor on a mark/t-bird/cougar he knew what i meant right away.

so if the rim was produced to be on the mark VIII studs wouldnt it be true without any kind of ring?

No, they're not, only the bolt pattern and offset was changed. I bought those same wheels from Brad, and they came with hubcentric rings. If you don't have these, your wheels are not hubcentric. I don't know what KK is saying, if he's saying stack has these same wheels without rings??

All I'm saying to you is to check that out on your wheels. You'll be able to pop it out like a center cap, except from the backside of the wheel.

If you have 'em, and still have a rotor problem, then yeah you need hubcentric rotor spacers. But WOULDN'T if the holes that were drilled were in any kind of decent spec because the wheels would hold the studs that the rotors are mounted on in place and act as a hubcentric ring for the rotor.

i wrote to the guy i bought the car from so he can refresh my memory as to what i need, he told me when i picked it up, it was 16 degrees out, we were putting all kinds of extra parts in the trunk, my buddy and my brother in law were there, there was a lot going on so i didnt pay much attention to it, but he will tell me what i need, i also wrote to Ed on tccoa and he has rings to put a cobra rotor on a mark/t-bird/cougar he knew what i meant right away.

Yeah. And I know what you mean also.

Regardless of anything with the rotor, you're going to want to make sure your wheels have those rings installed.

Your wheels, if from Brad, are not hubcentric without those rings. And that could be your whole problem.

I'll clear up all the confusion...

If you have the hubcentric rings they hold the wheel and the rotor on correctly...

I'll clear up all the confusion...

If you have the hubcentric rings they hold the wheel and the rotor on correctly...

Exactly. If you have hubcentric rings for the WHEELS, you should have NO problem regardless of your rotor having too large of a hole in the middle!! Lol

But if you DON'T have them you get vibrations... so call brad and get some hubcentric rings...

what the owner told me was just what you said, rotor spacers. but what i dont get is why you keep mentioning my wheels, if the wheels need hub rings, and i dont have them, then they would ride like ass wouldnt they, all 4 wheels roll mint, at 8 mph or 80 mph, the only time i have a problem with a vibration is when i step on the brakes, so what would the wheel have to do with a vibration when i hit the brakes hard? i guess i need to pull the wheels off this weekend and see for myself before i ask for help on something i havent even looked at myself yet! and yes they are from brad.

But understand that your wheels will roll ok without the rings, unless braking.. Because that's when the studs really get to work

Does it feel good upon acceleration too?

You might have the hubcentric rings on your wheels, I did mention that. And if you still have the problem, it's because the tolerance on the holes they drilled in your rotors suck. And then yes, rings for your rotors will fix the problem. I'm just saying you shouldn't need them if everything else is correct.

under acceleration it is perfect too, the only time you can feel it is when you hit that brake pedal, if you hit it light you dont feel it but if you hit it medium to hard oh wow!!!!

Yes you need hubcentric rings for the rear rotors on the hub. You can also get a set for the wheel while your at it.

Yes you need hubcentric rings for the rear rotors on the hub. You can also get a set for the wheel while your at it.

Wheel rings are a must.

he needs them for the rotors because the rotors are spaced out 5mm different on the cobra rotors vs the mark rotors... its just to get the rotors lined up with the calipers so that when the brake is applied the rotor doesnt get extra strain put on them...

he needs them for the rotors because the rotors are spaced out 5mm different on the cobra rotors vs the mark rotors... its just to get the rotors lined up with the calipers so that when the brake is applied the rotor doesnt get extra strain put on them...

But the caliper spacers make up for that, right?

(I was only saying with hubcentric wheels, and holes drilled correctly, and wheels that are on tight, the hubcentric part of the rotor shouldn't matter)

Man, I'd like some pictures of this stuff.

ponies, sorry but your totally missing whats happening. This has nothing at all to do with the wheels, or rings for the wheels...

Jamie, you will need rings for the rotors from Ed. I've put Cobra rotors on my car front and rear too, and got the rings from Ed with the brackets.

Lol, I must be.

But it shouldn't change the fact that if the wheels are hubcentric, the non hubcentric rotor shouldn't be able to move around, due to the wheel completely preventing the studs from flexing.

..I fully understand what you're saying Icarus.

But, don't overlook what I'm saying either. I know the rotors are not hubcentric. I am simply saying that the wheels make up for that fact.

I'm curious about the confusion, really. And if it's mine, I need educated.

Rings on the wheels won't help with a vibration only on braking, Jamie said it only does it then and mentioned they are not spinning true, so other than warped rotors (which would be in the other direction anyways) or maybe damaged hubs, this would be the fix most likely.

Wheel rings are only to help keep the wheel centered when installing it. This has nothing to do with Jamie's problem from all he's said it sounds like...

ok this is straight from someone who knows what i am talking about, and knows exactly what needs to be done....

Jamie, I've got a pair of those rings for the rotors ,
Ever seen a rotor that wasn't hub centric ? (well you will when you take the wheels off ) There is always some play in the stud holes,even if they were drilled correctly. That's why the rotor needs to be centered via hub, and not via lugs. Same goes for the wheels. OEM stuff always fits tight, and is vibe and issue free.

Wheel rings are only to help keep the wheel centered when installing it.

..And all the rest of the time, including the studs. Which the rotor rides on. Lol, I just quit man. Thanks for trying though.

ok this is straight from someone who knows what i am talking about, and knows exactly what needs to be done....

Jamie, I've got a pair of those rings for the rotors ,
Ever seen a rotor that wasn't hub centric ? (well you will when you take the wheels off ) There is always some play in the stud holes,even if they were drilled correctly. That's why the rotor needs to be centered via hub, and not via lugs. Same goes for the wheels. OEM stuff always fits tight, and is vibe and issue free.

That is right about the rotors, but wrong about the OEM wheels being hubcentric, as they will move when slid flush on the hub (not tight, ie sloppy.) Try it out with a stock rim if you don't believe me...
Most tire balancers balance hubcentrically as it's easier, but not always correct! The good adapters for balancing lugcentrically are expensive, complex and wear out, so most shops don't use them...

Another way to see if a wheel is hubcentric is to put one lug or bolt on just snug and see if you can slid the wheel around a bit till it hits the hub, which on our oems and most aftermarkets wheels you can (without any rings.) If it was hubcentric it would not move in any direction, as the hub would prevent this as it would have a snug fit on it...

Another way to see if a wheel is hubcentric is to put one lug or bolt on just snug and see if you can slid the wheel around a bit till it hits the hub, which on our oems and most aftermarkets wheels you can (without any rings.) If it was hubcentric it would not move in any direction, as the hub would prevent this as it would have a snug fit on it...

Those saleens with the rings are PRETTY tight IIRC.. so, with what I was thinking, do you think that with a tight hubcentric wheel, and a non-warped and non-hubcentric rotor, he would still get this vibration he's talking about? I mean, after the brake is engaged, unless he's on a slippery surface and the abs is kicking in, it should be smooth braking, right? Or no? This is what I'm trying to understand, inevitably..

Most tire balancers balance hubcentrically as it's easier, but not always correct! The good adapters for balancing lugcentrically are expensive, complex and wear out, so most shops don't use them...

Icarus-

I'm trying to understand this. This is the only method I've seen. Can you elaborate on the 'adapters'? I've always seen a cone so it sits tight on the hub center when they're spinning the wheel

Google lugcentric wheel balancer adapters and you'll see everything from cheap ones to good ones, I'm not looking this crap up for you...

Jamie,

it's prob not the cheapest route, but if your wheels are unilug get the cobra hub and be done with the hub centric crap all together. I am running the cobra hubs and 11.65 rotors with a stock mark viii caliper and adapter. I have never had any issues in the past six years, other than I don't like that the mark viii pad takes a smaller bite out of the rotor. I always have a "ring" of rust on the rotor about an inch or so wide where the pads aren't deep enough to grab the bigger rotor. Doesn't effect performance just one of those little things that annoys me.

Jamie,

it's prob not the cheapest route, but if your wheels are unilug get the cobra hub and be done with the hub centric crap all together. I am running the cobra hubs and 11.65 rotors with a stock mark viii caliper and adapter. I have never had any issues in the past six years, other than I don't like that the mark viii pad takes a smaller bite out of the rotor. I always have a "ring" of rust on the rotor about an inch or so wide where the pads aren't deep enough to grab the bigger rotor. Doesn't effect performance just one of those little things that annoys me.

this would be alright but he already has the nice wheels for the 5x4.25" bolt circle. the spacing on the Cobra hub and the mark VIII hub are like 5 mm difference or something which is why the mark VIII hub needs the spacer to go on before the rotor so that when the brakes are applied the rotor doesnt bind up... Poniesviii click the link that i put in the thread and read that it explains why you need the spacer ring for the rotor...

this would be alright but he already has the nice wheels for the 5x4.25" bolt circle. the spacing on the Cobra hub and the mark VIII hub are like 5 mm difference or something which is why the mark VIII hub needs the spacer to go on before the rotor so that when the brakes are applied the rotor doesnt bind up... Poniesviii click the link that i put in the thread and read that it explains why you need the spacer ring for the rotor...

YES

He is refering to an up and down motion of the rotor, not a side to side.

I was refering to the rotor being off center. If you were to look at the rotor from the wheel the rotor would appear to be moving up and down. When I said side to side, I meant like a warped rotor when looking at the rotor from its front.

Your lugnuts don't flex. Maybe the tiniest of margins, but nothing you could measure nor have it cause a problem while braking. I'd grab those hubcentric rings and if you still have a problem then obviously, you may need the rotors machined, but I doubt thats your problem. And if the wheels use a tapered lugnut, rather than a flat sided lugnut, they will hold them lug centric even if the wheels inner hub diameter was larger than the hub itself.