Bolt Pattern of Spare [Archive]

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St.Mary

10-13-2005, 08:33 PM

I was looking at my spare tire sitting in my room (don't ask) and I noticed that it only says "GM" and "USA" on it....nothing about a bolt pattern or offset. Anyone know....

The reason I ask is because I wonder if they just put a standart GM 120.65mm (4.75in) bolt pattern. This would help answer some questions as far as the relevance of 120 vs 120.65 bolt patterns.

Here is a link to the corvette forum where a guy was looking to put a GTO spare on his vette.....looks like it bolted up fine

Vette Link (http://forums.corvetteforum.com/showthread.php?t= 996692)

Pucci

10-13-2005, 08:50 PM

St.Mary

10-13-2005, 08:54 PM

It should be the EXACT same as what the wheels on the car are. I really dont think they would make a different bolt pattern for the spare. That would be SERIOUSLY unsafe. I sure as hell would be pissed if a wheel that is 4 inches wide didnt mount up flush to my car and it is the factory spare.

Pucci

Ahh very true. I too would be pissed if the wheels didn't bolt right up or were unsafe.

However, if GM did put a GM standard 4.75" bolt pattern on the spare, than that would be GM's way of saying 120 vs 120.65 doesn't really matter.

Still trying to put this issue to rest since it seems like a bunch of opinions floating around. People saying "I don't think they would be safe" kinda thing.

Lothar

10-13-2005, 08:59 PM

Get a piece of paper and a compass and measure it while you have it out.

Edit: I'm joking. I know you have no way to measure whether it's 120mm or 120.65mm

Pucci

10-13-2005, 08:59 PM

St.Mary

10-13-2005, 09:07 PM

You're damn right they wont be safe....That is if we are talking about putting them on the front for skinnies at the track. The tire is a SPARE rated tire...NOT DRAG! And the Rim is a SPARE, Not a drag skinny. I dont mean to be an ass here but use a little bit of a brain. You are just asking to see what the wall feels like at a 100+ mph.

Pucci

Hold on a minute. I'm not talking about running them for anything but a spare either (didn't think I made it sound that way). I realize that the SPARE is for temporary use only. I agree that using the spare as a skinny is dangerous....not questioning you there. :judge:

I am only asking about the bolt pattern. Please don't post what you think it "should be"....only if you either know what it is or have a link to an online source.

What I'm saying is that GM could have possibly used a GM standard bolt pattern for the spare (cost savings maybe, who knows). But if GM is willing to say 120.65 will work on a 120 spec car, than maybe we have our answer.

Pucci

10-13-2005, 09:10 PM

OK I stand corrected. I apologize. I wonder if you take it to a wheel/tire place if they have a toy to tell you bolt pattern.

Pucci

HTRDLNCN

10-13-2005, 09:17 PM

Considering this car has been selling now for 5-6 years Im pretty sure the rim is Holden specific. I doubt they changed the spare tire just for us yanks..

St.Mary

10-13-2005, 09:18 PM

OK I stand corrected. I apologize. I wonder if you take it to a wheel/tire place if they have a toy to tell you bolt pattern.

Pucci

All good. Just making sure we are on the same page here.

I am just looking for some solid answers as to whether we can use vette/camaro/etc (4.75" standard GM) rims on these cars which would give us a much wider variety.

Many have done it with no problems, yet I have heard of the occasional story where people had issues. It seems that people that have actually tried say they look like they fit fine, but still feel cautious about going fast on a "non-spec" wheel but may still have no problem running them at the strip on weekends. Most of the people saying "no they won't work" are just expressing their opinions, looking at 2 numbers that aren't identical, and saying it can't/shouldn't be done.

Come on, what if the difference is just the english vs metric comparison (120mm vs 4 3/4"). Honestly, why would America list a 120mm rim and vica versa. Also, look at the difference here.... 0.65mm on a diameter (comes out to .012" on the radius) which is probably within the true position tolerance of the lugs and bolt circle anyways (although I don't have any real proof to back this up).

The only reason i keep dragging this out is that I am seriously considering some of the aftermarket C5 replica rims (offsets and sizes to fit too)....its just this bolt pattern issue and nobody to this day has a solid answer.

Pucci

10-13-2005, 09:20 PM

eeww he said that work....Yanks. I am only STUCK in Rhode Island......I am a Texan at heart so that makes me a Redneck.

Pucci

HTRDLNCN

10-13-2005, 10:02 PM

Yanks as in all Americans to the Aussies.
:)

Im a New Yorker living in Florida and moving to Texas..
;)

miscreant

10-15-2005, 08:53 PM

Again, no offense, but ANOTHER moot point about 120 vs 120.65.

1) The wheel and tire come from australia, shipped in the car, from australia. I can guarantee that it's 120mm.
2) You CAN, CAN, CAN, CAN!!!!!!!!!!! bolt a 120.65mm wheel on the GTO. It WILL BOLT UP....let me repeat this in case anyone missed that - IT WILL BOLT UP. However...
3) .65mm may seem like very little difference, but when the wheel is ALSO not hubcentric, it becomes a big deal. On rotating mass, it's amplified exponentially. If you bolt it on wrong, and being the wrong bolt pattern and NOT hub centric, it's easier to do, you will have problems.
4) Add hub centric rings to help make sure the wheel is center will help out a ton, BUT...
5) I know of no C5 replica wheels that will fit the front of the Goat without spacers, and adding spacers to the equation of already having the wrong bolt pattern is a NO-NO in my book big time. You'll need new lug bolts first of all - longer ones- and when you lengthen them, then space the lug nuts out farther and offset them off-center as you would on a 120.65mm pattern, you are asking for more problems - as now the lug has more flex (it's longer) and you stand more chance of lug nut walk from having unequal pressure around the bolting surface.

And also be aware that even if GM used a 120.65mm bolt pattern on the "TEMPORARY USE" spare, it does not mean jack that 120.65mm is the appropriate use bolt pattern for daily driving. That would be like saying that the tread compound on the spare was adequate for daily use.

05 red tomcat

10-15-2005, 09:42 PM

anyone know about swaping the hub to get the 4.75 bolt patern there are a lot more wheels to choose from.l

04PhantomM6

10-15-2005, 10:10 PM

anyone know about swaping the hub to get the 4.75 bolt patern there are a lot more wheels to choose from.l

Your talking about upgrading to C5 brakes? Sounds pricey at best. Jut but a set of Foose wheels, or Boyds - then it has the same specs on wheels.

Look at BMW 3xx series wheels, many will bolt up with correct offset.

St.Mary

10-17-2005, 06:16 PM

Your talking about upgrading to C5 brakes? Sounds pricey at best. Jut but a set of Foose wheels, or Boyds - then it has the same specs on wheels.

Look at BMW 3xx series wheels, many will bolt up with correct offset.

Here is a writeup someone did for basically swapping out a wheel bearing/hub.

How many of these parts would we end up swapping?
Vette Hub Replacement/ (http://www.jakelatham.com/C5/misc/)

sccaGTO

10-17-2005, 08:52 PM

Here is a writeup someone did for basically swapping out a wheel bearing/hub.

How many of these parts would we end up swapping?
Vette Hub Replacement/ (http://www.jakelatham.com/C5/misc/)
Don't know how much trouble it would be, but I don't have the $$ to try. We are talking about 2 of the most expensive cars in the GM lineup. Parts for neither car are cheap.

2) You CAN, CAN, CAN, CAN!!!!!!!!!!! bolt a 120.65mm wheel on the GTO. It WILL BOLT UP....let me repeat this in case anyone missed that - IT WILL BOLT UP. However...
Here is what I have learned in the GTO vs. GM wheel war. GM's 'Vette/F-bodies have BIGGER center bore holes than the GTO. So, spare rim or regular rim, the GTO rim on a 'Vette will not go over the hub at all. If they were the same bore size, the GTO spare might rub on the 'Vette caliper.

The moral of the story is, we need Boyd's to make a wheel just like our spare rims. :p

24v

10-18-2005, 04:59 AM

So, spare rim or regular rim, the GTO rim on a 'Vette will not go over the hub at all.
You sure about that?
http://img.photobucket.com/albums/v239/cuspid/vett e.jpg
Check the link in post #1.:bunny:

sccaGTO

10-18-2005, 08:13 AM

You sure about that?

Check the link in post #1.:bunny:
I did. But, you do the math. The GTO hub is 69.5 mm. The 'Vette should be the same as the F-body, which is like 72mm.

24v

10-18-2005, 10:21 AM

I did. But, you do the math. The GTO hub is 69.5 mm. The 'Vette should be the same as the F-body, which is like 72mm.
Then how did that wheel fit on the vette in the picture I pulled from that thread?

sccaGTO

10-18-2005, 01:31 PM

Then how did that wheel fit on the vette in the picture I pulled from that thread?
I guess whomever did that could have forced it on there. The person who posted that in the Corvette forum didn't say if it was difficult to take the wheel off.

St.Mary

10-18-2005, 06:48 PM

He did say it was snug though. And honestly, if you have a 2mm interference, you are going to need a sledge hammer to get those on there!

St.Mary

10-18-2005, 06:51 PM

Sorry, info for me only....

I PM'd the guy and asked how things fit. This was where he said they bolted up fine and the centerbore was "snug" but still slid on.

Check this pichttp://img.photobucket.com/albums/v239/cuspid/s pareonvet.jpg

05 red tomcat

10-30-2005, 05:44 PM

so we need a ring to use f-body wheels .im all for that

Galen

10-31-2005, 03:01 AM

Ya'll use whatever you like. As for me, I have already mounted Weld Wheels on my goat with NO issues. As a matter of fact, I want to know of anyone who has had issues with running a 4 3/4 bolt circle. To put this in perspective, GM has been using the same bolt circle since before the early 1950's (as far back as I know about). The difference in radius is 0.012795 of an inch. I seriously doubt that the mass production of hubs in the 1950's was nearly this accurate. Also, non-hubcentric rims have been used for decades also...with no ill effects. There will always be someone who says it can't be done...then there will be those of us who do it anyway. Hell, following the laws of physics, a bumble bee can't fly either...but don't tell the bee that!

I went ahead and captured a pic of the Monaro that Kurt from DiffTechniques owns...anyone wanna guess who makes those wheels? Cough...cough...Cragar...cough. I am sure that if the Aussies had any problems with the rims flying off at speed, we would have heard something about it by now.

http://www.rmgto.com/gallery/albums/album03/KurtMo naro.gif

Galen

St.Mary

10-31-2005, 04:20 AM

Galen, do you run those rims all the time, or just at the track? How many miles on them?

Your also telling me they are lug centric....not hub?

sccaGTO

10-31-2005, 06:00 AM

Galen, do you run those rims all the time, or just at the track? How many miles on them?

Your also telling me they are lug centric....not hub?
From everything I've read, he uses the daily. They aren't track only wheels. They are not hub-centric, either.

Galen

10-31-2005, 08:17 AM

They will be track only...hell, they still have MT ET Drags on them. The ET Drags are too wide, at least on the driver's side. This may be due to me slapping the driver's side fender once and the body shop not bringing the fender all the way out. I will be putting some Nitto DRs on them and seeing how they go.

As far as if they will be daily driven...no. I have had too many drag race only cars, and this isn't going to be one of them. Anyone who drives skinnies on a daily basis has a far greater definition of streatable than I do. I really like to take a few curves also. I will, however, be using them extensively on the street when I decide to go prowlin and growlin! You may want to ask Kurt if his are everyday use and how long he has been running them.

Oh yea, to the best of my knowledge, all Weld, Crager, Centerline, American and any other of the various drag racing rims are lug centric. The Bogarts may be hub centric...if they went through the trouble to adjust the bolt spacing .325mm each, surely they made the rim "right" by making it hub centric.

To see for yourself, find one of your friends with some frontrunners. They are easy to take off and switch. Take your front rim off and put one on your car. On all the Weld Wheels I have used, they require a lug that pass through the rim. The shank of the lug is a snug fit as it goes through the rim, as in there is no side play with the lug sitting in the rim. With all four of the rims on my car, the lugs started easily and were able to be turned hand tight most of the way into the rim. If the bolt spacing were an issue, I feel I would not have been able to easily start all lugs, as the spacing would prevent this. I would not hesitate to purchase 4 3/4 rims for daily use, but would pay much closer attention to backspacing than I did for a limited use tire.

Hope this helps!

Galen

Edited for just got outta bed spelling!

nikivee

10-31-2005, 08:47 AM