New 15x8 wheels
Le Mans Master
Joined: Nov 2016
Posts: 9,261
Likes: 950
From: Lake Tahoe, CA
So I measured my wheels and it is 3.5" backspacing from the bead to the mounting pad and it is 4" backspacing from the lip, as if you laid the wheel down flat on the floor and measured up to the mounting pad.
On various websites I see either one of these measurements as the backspacing. Good grief.
I just ordered 4 Wheel Vintiques 15x8 with 4" backspacing from Summit. Hopefully these will work. $103 each w/free shipping. Can return to the Summit here in Arlington if they don't fit.
Wish I could have just gone down there and measured one but they don't have any in stock there.
Now if I can find a tire store that can balance lug centric verses the now common hub centric...
Also noticed that if you get 17" aluminum rallys, you can't use the stock rally hub caps.
On various websites I see either one of these measurements as the backspacing. Good grief.
I just ordered 4 Wheel Vintiques 15x8 with 4" backspacing from Summit. Hopefully these will work. $103 each w/free shipping. Can return to the Summit here in Arlington if they don't fit.
Wish I could have just gone down there and measured one but they don't have any in stock there.
Now if I can find a tire store that can balance lug centric verses the now common hub centric...
Also noticed that if you get 17" aluminum rallys, you can't use the stock rally hub caps.
Question: Ummm....How does balancing it relate to hub or lug centric? The fact that the center hole in the wheel is the same size as the hub or not doesn't affect the balancing process of the wheel. Please explain this for me.Will gladly explain, but keep in mind, not all center holes in wheels are the exact same size as the hub. A lot of wheels such as the 5 spoke Z28 wheel and Magnum 500 wheels don't even mount with the center hole on the hub and are instead "centered" after you tighten the lugnuts down.
Basically put, the center hole of a lug centric wheel is "not" the actual "true center" of the wheel and is actually there for the center cap ornamentation. The center hole is not exactly perfectly centered. This is particularly true with a "stamped" steel wheel such as the Magnum 500 wheel or our Z28 5 spoke wheels. These wheels get their true center when they are torqued down at the lugs as the stamped steel around the lugnut holes bends or distorts into correct place when it is tightened down to the hub which would affect the overall centering and balancing of the wheel which is why they need to be torqued down and balanced at the lugs vs. a cone through the center hole.
Think about it, how many of you have had your Z28 5 spoke wheels balanced at a regular tire place that does it using the cone/hub centric method only to still have some sort of vibration at certain speeds or what not with the wheels? Then you just assume the wheel is slightly bent or warped or what not.
Although the cone/hub-centric method can get it pretty close, and some people may not have problems or notice any issues with it done that way until you get up to higher speeds, but it still isn't accurate. When you bolt the wheels on, the metal around the lug nuts will bend and distort into proper center alignment against the hub throwing off the balance if done previously through the cone/hub-centric method.
Here is an article I found and copied from the internet that also explains it a little better also:
Hub Centric vs. Lug Centric
Hub Centric Wheels are centered by the center bore of the wheel and the hub flange.
Lug centric wheels are centered by the torque of the lug bolts; rather than the center bore of the wheel and the hub flange.
There are two distinct types of wheels found on today's cars and light trucks. There are Hub Centric wheels and there are Lug Centric wheels.
The most common wheels are Hub Centric in design. The center hole of these wheels is the actual center bore of the wheel. These wheels can be properly mounted and accurately balanced using the standard cone system supplied with most off car computer balancers.
Many of today's aftermarket wheels are Lug Centric in design. The center hole of a Lug Centric wheel is not the true center. These wheels cannot be properly mounted and accurately balanced using the normal cone mounting system that came with your wheel balancer.
Many Lug Centric wheels may appear to be mounted correctly with the center cone system, but they cannot be accurately balanced. The wheel balancer will continue to either "chase weights" or the wheel will show signs of imbalance when re-mounted on the vehicle.
To ensure an accurate balance, Lug Centric wheels must be mounted on the balancer through their lug bolt pattern. Lug Centric wheels, when mounted on the vehicle, are centered by the torque of the lug bolts and not the center bore of the wheel.
The only way to properly balance Lug Centric is through their lug bolt pattern. This style wheel must be mounted to the computer balancer in the same manner as it is mounted on the vehicle...through the lug bolt pattern.
Lug centric mounting on the wheel balancer mimics the way the wheel is mounted to the vehicle.
If you are balancing Lug Centric wheels, you must use the Atlas® Universal Adapter. The standard cone system will not work properly.
Melting Slicks
Joined: Sep 2015
Posts: 2,757
Likes: 333
From: Southampton MA
Le Mans Master
Joined: Oct 2010
Posts: 6,937
Likes: 848
From: melbourne florida
2023 C3 of the Year Finalist - Modified
I've bubble balanced 14 32 15 w drag slicks and been 180 mph on them and no tire wheel vibration or shake. If you need hub centric wheels to be happy the c3 forum may not be for you. None of these cars came with your beloved hub centric wheels.
🤣🤣🤣
🤣🤣🤣
Thread Starter
Race Director
Joined: Feb 2001
Posts: 11,301
Likes: 2,096
From: Grapevine Tx
2018 C3 of Year Finalist
2016 C3 of the Year Finalist
Learned something new today. Hub centric Vs Lug centric. Thanks
Question: Ummm....How does balancing it relate to hub or lug centric? The fact that the center hole in the wheel is the same size as the hub or not doesn't affect the balancing process of the wheel. Please explain this for me.
Will gladly explain, but keep in mind, not all center holes in wheels are the exact same size as the hub. A lot of wheels such as the 5 spoke Z28 wheel and Magnum 500 wheels don't even mount with the center hole on the hub and are instead "centered" after you tighten the lugnuts down.
Basically put, the center hole of a lug centric wheel is "not" the actual "true center" of the wheel and is actually there for the center cap ornamentation. The center hole is not exactly perfectly centered. This is particularly true with a "stamped" steel wheel such as the Magnum 500 wheel or our Z28 5 spoke wheels. These wheels get their true center when they are torqued down at the lugs as the stamped steel around the lugnut holes bends or distorts into correct place when it is tightened down to the hub which would affect the overall centering and balancing of the wheel which is why they need to be torqued down and balanced at the lugs vs. a cone through the center hole.
Think about it, how many of you have had your Z28 5 spoke wheels balanced at a regular tire place that does it using the cone/hub centric method only to still have some sort of vibration at certain speeds or what not with the wheels? Then you just assume the wheel is slightly bent or warped or what not.
Although the cone/hub-centric method can get it pretty close, and some people may not have problems or notice any issues with it done that way until you get up to higher speeds, but it still isn't accurate. When you bolt the wheels on, the metal around the lug nuts will bend and distort into proper center alignment against the hub throwing off the balance if done previously through the cone/hub-centric method.
Here is an article I found and copied from the internet that also explains it a little better also:
Hub Centric vs. Lug Centric
Hub Centric Wheels are centered by the center bore of the wheel and the hub flange.
Lug centric wheels are centered by the torque of the lug bolts; rather than the center bore of the wheel and the hub flange.
There are two distinct types of wheels found on today's cars and light trucks. There are Hub Centric wheels and there are Lug Centric wheels.
The most common wheels are Hub Centric in design. The center hole of these wheels is the actual center bore of the wheel. These wheels can be properly mounted and accurately balanced using the standard cone system supplied with most off car computer balancers.
Many of today's aftermarket wheels are Lug Centric in design. The center hole of a Lug Centric wheel is not the true center. These wheels cannot be properly mounted and accurately balanced using the normal cone mounting system that came with your wheel balancer.
Many Lug Centric wheels may appear to be mounted correctly with the center cone system, but they cannot be accurately balanced. The wheel balancer will continue to either "chase weights" or the wheel will show signs of imbalance when re-mounted on the vehicle.
To ensure an accurate balance, Lug Centric wheels must be mounted on the balancer through their lug bolt pattern. Lug Centric wheels, when mounted on the vehicle, are centered by the torque of the lug bolts and not the center bore of the wheel.
The only way to properly balance Lug Centric is through their lug bolt pattern. This style wheel must be mounted to the computer balancer in the same manner as it is mounted on the vehicle...through the lug bolt pattern.
Lug centric mounting on the wheel balancer mimics the way the wheel is mounted to the vehicle.
If you are balancing Lug Centric wheels, you must use the Atlas® Universal Adapter. The standard cone system will not work properly.
Question: Ummm....How does balancing it relate to hub or lug centric? The fact that the center hole in the wheel is the same size as the hub or not doesn't affect the balancing process of the wheel. Please explain this for me.Will gladly explain, but keep in mind, not all center holes in wheels are the exact same size as the hub. A lot of wheels such as the 5 spoke Z28 wheel and Magnum 500 wheels don't even mount with the center hole on the hub and are instead "centered" after you tighten the lugnuts down.
Basically put, the center hole of a lug centric wheel is "not" the actual "true center" of the wheel and is actually there for the center cap ornamentation. The center hole is not exactly perfectly centered. This is particularly true with a "stamped" steel wheel such as the Magnum 500 wheel or our Z28 5 spoke wheels. These wheels get their true center when they are torqued down at the lugs as the stamped steel around the lugnut holes bends or distorts into correct place when it is tightened down to the hub which would affect the overall centering and balancing of the wheel which is why they need to be torqued down and balanced at the lugs vs. a cone through the center hole.
Think about it, how many of you have had your Z28 5 spoke wheels balanced at a regular tire place that does it using the cone/hub centric method only to still have some sort of vibration at certain speeds or what not with the wheels? Then you just assume the wheel is slightly bent or warped or what not.
Although the cone/hub-centric method can get it pretty close, and some people may not have problems or notice any issues with it done that way until you get up to higher speeds, but it still isn't accurate. When you bolt the wheels on, the metal around the lug nuts will bend and distort into proper center alignment against the hub throwing off the balance if done previously through the cone/hub-centric method.
Here is an article I found and copied from the internet that also explains it a little better also:
Hub Centric vs. Lug Centric
Hub Centric Wheels are centered by the center bore of the wheel and the hub flange.
Lug centric wheels are centered by the torque of the lug bolts; rather than the center bore of the wheel and the hub flange.
There are two distinct types of wheels found on today's cars and light trucks. There are Hub Centric wheels and there are Lug Centric wheels.
The most common wheels are Hub Centric in design. The center hole of these wheels is the actual center bore of the wheel. These wheels can be properly mounted and accurately balanced using the standard cone system supplied with most off car computer balancers.
Many of today's aftermarket wheels are Lug Centric in design. The center hole of a Lug Centric wheel is not the true center. These wheels cannot be properly mounted and accurately balanced using the normal cone mounting system that came with your wheel balancer.
Many Lug Centric wheels may appear to be mounted correctly with the center cone system, but they cannot be accurately balanced. The wheel balancer will continue to either "chase weights" or the wheel will show signs of imbalance when re-mounted on the vehicle.
To ensure an accurate balance, Lug Centric wheels must be mounted on the balancer through their lug bolt pattern. Lug Centric wheels, when mounted on the vehicle, are centered by the torque of the lug bolts and not the center bore of the wheel.
The only way to properly balance Lug Centric is through their lug bolt pattern. This style wheel must be mounted to the computer balancer in the same manner as it is mounted on the vehicle...through the lug bolt pattern.
Lug centric mounting on the wheel balancer mimics the way the wheel is mounted to the vehicle.
If you are balancing Lug Centric wheels, you must use the Atlas® Universal Adapter. The standard cone system will not work properly.
Thread Starter
Race Director
Joined: Feb 2001
Posts: 11,301
Likes: 2,096
From: Grapevine Tx
2018 C3 of Year Finalist
2016 C3 of the Year Finalist
I
But then you come across this chart...
https://image.mamotorworksmedia.com/production/website/articlefiles/TechTipFiles/C3_Tire_Reference_Guide.pdf
I measured my wheels the same way and came up with 4". What gets me is Eklers, Zip, and Mid America all only sell 4.25 backspace rallys and Eklers says to use a 1/4" spacer.
Oh well, Summit came through. Never thought buying a rally wheel would be so complicated.
Also, if you read the description of backspacing in A10's first pic, it says measure from the inboard flange, not the outer lip but their pic shows from the outer lip. Ahhhhhhhhh!
Cheers.
https://image.mamotorworksmedia.com/production/website/articlefiles/TechTipFiles/C3_Tire_Reference_Guide.pdf
I measured my wheels the same way and came up with 4". What gets me is Eklers, Zip, and Mid America all only sell 4.25 backspace rallys and Eklers says to use a 1/4" spacer.
Oh well, Summit came through. Never thought buying a rally wheel would be so complicated.
Also, if you read the description of backspacing in A10's first pic, it says measure from the inboard flange, not the outer lip but their pic shows from the outer lip. Ahhhhhhhhh!
Cheers.
Last edited by F4Gary; Oct 19, 2021 at 10:04 PM.
Melting Slicks
Joined: Sep 2015
Posts: 2,757
Likes: 333
From: Southampton MA
I
But then you come across this chart...
https://image.mamotorworksmedia.com/production/website/articlefiles/TechTipFiles/C3_Tire_Reference_Guide.pdf
I measured my wheels the same way and came up with 4". What gets me is Eklers, Zip, and Mid America all only sell 4.25 backspace rallys and Eklers says to use a 1/4" spacer.
Oh well, Summit came through. Never thought buying a rally wheel would be so complicated.
Also, if you read the description of backspacing in A10's first pic, it says measure from the inboard flange, not the outer lip but their pic shows from the outer lip. Ahhhhhhhhh!
Cheers.
But then you come across this chart...
https://image.mamotorworksmedia.com/production/website/articlefiles/TechTipFiles/C3_Tire_Reference_Guide.pdf
I measured my wheels the same way and came up with 4". What gets me is Eklers, Zip, and Mid America all only sell 4.25 backspace rallys and Eklers says to use a 1/4" spacer.
Oh well, Summit came through. Never thought buying a rally wheel would be so complicated.
Also, if you read the description of backspacing in A10's first pic, it says measure from the inboard flange, not the outer lip but their pic shows from the outer lip. Ahhhhhhhhh!
Cheers.
This is not "pilot proof". Good Luck !
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I didn't like my stock 79 l-82 aluminum wheels so I bought 8.5X15 lighter american racing with 4.25 BS. They were great for many years until they quit making "Z" rated 15's so I put them on my 67 RS/SS Camaro. So I put on 17's 9 front and 11 inch rear at first.
Summit racing has a whole line up of 15 inch wheels. These were something like $135 each. I bought these in July. 10X15 with 4 inch BS to mount a set of road racing slicks just to goof off with out street driving for the car shows.
I gave people rides and did dozens of 100 plus yard burn outs and went to a big industrial parking lot drifter course for a day. Just good cheap fun burning up slicks.
Summit racing has a whole line up of 15 inch wheels. These were something like $135 each. I bought these in July. 10X15 with 4 inch BS to mount a set of road racing slicks just to goof off with out street driving for the car shows.
I gave people rides and did dozens of 100 plus yard burn outs and went to a big industrial parking lot drifter course for a day. Just good cheap fun burning up slicks.
Last edited by gkull; Oct 20, 2021 at 10:20 AM.
Thread Starter
Race Director
Joined: Feb 2001
Posts: 11,301
Likes: 2,096
From: Grapevine Tx
2018 C3 of Year Finalist
2016 C3 of the Year Finalist
So I got one of my Wheel Vintique rally wheels and took it and my crappy spare rim over to my son to have him mount or remount them.
Turns out the center hole on the new wheels is an 1/8th of an inch bigger than the old factory rims. Not a big deal as they have different size centering cones but I just thought this was interesting.
Turns out the center hole on the new wheels is an 1/8th of an inch bigger than the old factory rims. Not a big deal as they have different size centering cones but I just thought this was interesting.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Race Director
Joined: Feb 2001
Posts: 11,301
Likes: 2,096
From: Grapevine Tx
2018 C3 of Year Finalist
2016 C3 of the Year Finalist
Burning Brakes
Joined: Oct 2009
Posts: 1,066
Likes: 57
Learned something new today. Hub centric Vs Lug centric. Thanks
Question: Ummm....How does balancing it relate to hub or lug centric? The fact that the center hole in the wheel is the same size as the hub or not doesn't affect the balancing process of the wheel. Please explain this for me.
Will gladly explain, but keep in mind, not all center holes in wheels are the exact same size as the hub. A lot of wheels such as the 5 spoke Z28 wheel and Magnum 500 wheels don't even mount with the center hole on the hub and are instead "centered" after you tighten the lugnuts down.
Basically put, the center hole of a lug centric wheel is "not" the actual "true center" of the wheel and is actually there for the center cap ornamentation. The center hole is not exactly perfectly centered. This is particularly true with a "stamped" steel wheel such as the Magnum 500 wheel or our Z28 5 spoke wheels. These wheels get their true center when they are torqued down at the lugs as the stamped steel around the lugnut holes bends or distorts into correct place when it is tightened down to the hub which would affect the overall centering and balancing of the wheel which is why they need to be torqued down and balanced at the lugs vs. a cone through the center hole.
Think about it, how many of you have had your Z28 5 spoke wheels balanced at a regular tire place that does it using the cone/hub centric method only to still have some sort of vibration at certain speeds or what not with the wheels? Then you just assume the wheel is slightly bent or warped or what not.
Although the cone/hub-centric method can get it pretty close, and some people may not have problems or notice any issues with it done that way until you get up to higher speeds, but it still isn't accurate. When you bolt the wheels on, the metal around the lug nuts will bend and distort into proper center alignment against the hub throwing off the balance if done previously through the cone/hub-centric method.
Here is an article I found and copied from the internet that also explains it a little better also:
Hub Centric vs. Lug Centric
Hub Centric Wheels are centered by the center bore of the wheel and the hub flange.
Lug centric wheels are centered by the torque of the lug bolts; rather than the center bore of the wheel and the hub flange.
There are two distinct types of wheels found on today's cars and light trucks. There are Hub Centric wheels and there are Lug Centric wheels.
The most common wheels are Hub Centric in design. The center hole of these wheels is the actual center bore of the wheel. These wheels can be properly mounted and accurately balanced using the standard cone system supplied with most off car computer balancers.
Many of today's aftermarket wheels are Lug Centric in design. The center hole of a Lug Centric wheel is not the true center. These wheels cannot be properly mounted and accurately balanced using the normal cone mounting system that came with your wheel balancer.
Many Lug Centric wheels may appear to be mounted correctly with the center cone system, but they cannot be accurately balanced. The wheel balancer will continue to either "chase weights" or the wheel will show signs of imbalance when re-mounted on the vehicle.
To ensure an accurate balance, Lug Centric wheels must be mounted on the balancer through their lug bolt pattern. Lug Centric wheels, when mounted on the vehicle, are centered by the torque of the lug bolts and not the center bore of the wheel.
The only way to properly balance Lug Centric is through their lug bolt pattern. This style wheel must be mounted to the computer balancer in the same manner as it is mounted on the vehicle...through the lug bolt pattern.
Lug centric mounting on the wheel balancer mimics the way the wheel is mounted to the vehicle.
If you are balancing Lug Centric wheels, you must use the Atlas® Universal Adapter. The standard cone system will not work properly.
Question: Ummm....How does balancing it relate to hub or lug centric? The fact that the center hole in the wheel is the same size as the hub or not doesn't affect the balancing process of the wheel. Please explain this for me.Will gladly explain, but keep in mind, not all center holes in wheels are the exact same size as the hub. A lot of wheels such as the 5 spoke Z28 wheel and Magnum 500 wheels don't even mount with the center hole on the hub and are instead "centered" after you tighten the lugnuts down.
Basically put, the center hole of a lug centric wheel is "not" the actual "true center" of the wheel and is actually there for the center cap ornamentation. The center hole is not exactly perfectly centered. This is particularly true with a "stamped" steel wheel such as the Magnum 500 wheel or our Z28 5 spoke wheels. These wheels get their true center when they are torqued down at the lugs as the stamped steel around the lugnut holes bends or distorts into correct place when it is tightened down to the hub which would affect the overall centering and balancing of the wheel which is why they need to be torqued down and balanced at the lugs vs. a cone through the center hole.
Think about it, how many of you have had your Z28 5 spoke wheels balanced at a regular tire place that does it using the cone/hub centric method only to still have some sort of vibration at certain speeds or what not with the wheels? Then you just assume the wheel is slightly bent or warped or what not.
Although the cone/hub-centric method can get it pretty close, and some people may not have problems or notice any issues with it done that way until you get up to higher speeds, but it still isn't accurate. When you bolt the wheels on, the metal around the lug nuts will bend and distort into proper center alignment against the hub throwing off the balance if done previously through the cone/hub-centric method.
Here is an article I found and copied from the internet that also explains it a little better also:
Hub Centric vs. Lug Centric
Hub Centric Wheels are centered by the center bore of the wheel and the hub flange.
Lug centric wheels are centered by the torque of the lug bolts; rather than the center bore of the wheel and the hub flange.
There are two distinct types of wheels found on today's cars and light trucks. There are Hub Centric wheels and there are Lug Centric wheels.
The most common wheels are Hub Centric in design. The center hole of these wheels is the actual center bore of the wheel. These wheels can be properly mounted and accurately balanced using the standard cone system supplied with most off car computer balancers.
Many of today's aftermarket wheels are Lug Centric in design. The center hole of a Lug Centric wheel is not the true center. These wheels cannot be properly mounted and accurately balanced using the normal cone mounting system that came with your wheel balancer.
Many Lug Centric wheels may appear to be mounted correctly with the center cone system, but they cannot be accurately balanced. The wheel balancer will continue to either "chase weights" or the wheel will show signs of imbalance when re-mounted on the vehicle.
To ensure an accurate balance, Lug Centric wheels must be mounted on the balancer through their lug bolt pattern. Lug Centric wheels, when mounted on the vehicle, are centered by the torque of the lug bolts and not the center bore of the wheel.
The only way to properly balance Lug Centric is through their lug bolt pattern. This style wheel must be mounted to the computer balancer in the same manner as it is mounted on the vehicle...through the lug bolt pattern.
Lug centric mounting on the wheel balancer mimics the way the wheel is mounted to the vehicle.
If you are balancing Lug Centric wheels, you must use the Atlas® Universal Adapter. The standard cone system will not work properly.
None of the many tire shops in my area were even familiar with these adapters, or even the term 'lug centric'. I finally found a shop that had the adapter, but none of the staff knew how to use it.
I would happily buy a new set of stock-looking 15" Rally wheels (aluminum or steel) that were able to be hub centric balanced. Regrettably, I don't think such an item exists.
Administrator
Joined: Jul 2000
Posts: 53,984
Likes: 6,212
From: About 1100 miles from where I call home.
I went through this balancing nightmare mounting new tires on my stock '71 Convertible. You must use a Haweka or Atlas adapter when balancing stock, steel C3 wheels. Balancing with a cone will not work correctly.
None of the many tire shops in my area were even familiar with these adapters, or even the term 'lug centric'. I finally found a shop that had the adapter, but none of the staff knew how to use it.
I would happily buy a new set of stock-looking 15" Rally wheels (aluminum or steel) that were able to be hub centric balanced. Regrettably, I don't think such an item exists.
None of the many tire shops in my area were even familiar with these adapters, or even the term 'lug centric'. I finally found a shop that had the adapter, but none of the staff knew how to use it.
I would happily buy a new set of stock-looking 15" Rally wheels (aluminum or steel) that were able to be hub centric balanced. Regrettably, I don't think such an item exists.