Introduction
Apparently, some car enthusiasts are not aware of the crucial importance of using hub rings when installing aftermarket wheels. In fact, some don't even know of their existence. Since this is an extremely important topic affecting both handling and safety concerns for our cars, I thought it a good idea to ensure that more of our members have access to this information.
Why Hub Rings?
OEM alloy and steel wheels are manufactured to have a centerbore diameter exactly sized to match that of the vehicle hub. This ensures that the wheel is solidly supported by the hub, giving what's called a hubcentric mounting. Here, the lugs and lug nuts function to hold the wheel to the hub, but do not support its weight. The lugs are not designed to be a weight-bearing component by themselves - their primary function, in conjunction with the lug nuts, is to solidly fasten the wheel to the hub assembly.
By contrast, most aftermarket wheels (except those specifically designed for a specific model; in which case the centerbore is matched to the vehicle hub size) are made with a centerbore diameter much larger than most vehicle hub diameters. This enables a single aftermarket wheel type to fit a wide variety of cars and models. If such a wheel is mounted on the car, it will only be supported by the lugs (called a lugcentric mounting) giving rise to possible movement between wheel and hub during cornering and acceleration, vibration, and excessive wheel bearing wear, including possible structural failure of the lugs themselves. The problem is made even worse when fitting a wheel of less positve offset than OEM design because it places an additional strain on the wheel bearings and lugs.
To provide the desired hubcentric mounting of aftermarket wheels, hub rings are employed. The inner diameter of the hub ring is sized to just fit over the car's wheel hub (slip fit) while the outer diameter of the hub ring is sized to fit the wheels centerbore (slip fit or light push fit). So installed, hub rings enable the correct hubcentric mounting of any aftermarket wheel. For those of you who minimize the importance of hubcentric mounting, TheMAN has pointed out that no Japanese car is designed to use lugcentric mounting; why should the wheels on your car use an inferior method of attachment as compared with OEM?
In order to select the correct size hub rings, we have to know both the hub diameter of our car and the centerbore diameter of the aftermarket wheel in question. If a listing can't be found for your vehicle's hub diameter, it's easy enough to measure this dimension on your own. A decent caliper or micrometer (2" to 3" range for most purposes) will easily do the job. Once the hub diameter is known, select a ring whose i.d. matches it and you're all set.
Hub Diameters
All 4-lug Proteges: 54.1mm
All 5-lug Proteges: 67.1mm
323 ('86-'89): 59.61mm
323 ('90-'95): 54.1mm
MX3: 54.1mm
3: 67.1mm
626 ('83-'92): 59.61mm
626 ('93-'02): 67.1mm
Millenia: 67.1mm
6: 67.1mm
MPV: 67.1mm
5: 67.1mm
Thanks to firelizard for providing a number of the hub dimensions listed above.
Finding Centerbore Diameters
Centerbore diameters vary greatly depending on the manufacturer. Some manufacturers, for example Enkei, list centerbore diameters on their website; most, but by no means all Enkei centerbores are 72.6 mm.
Others such as 5Zigen do not. Again, in the absence of a listing, the centerbore diameter can be determined using a caliper or inside micrometer. I know the FN01R-C wheels have a 73 mm centerbore because I measured it myself. However, that doesn't necessarily mean all their wheels have this same dimension.
Rota fans are fortunate because a Canadian website lists the centerbore diameters of all their wheels.
When you buy wheels online, some dealers will provide the correct hub rings as long as they know your car model, relieving you of the task of discovering the dimension on your own. Hub rings can also be bought separately from a variety of sources.
Installing Hub Rings
Hub rings are available in both polycarbonate plastic and aluminum. I use aluminum types because some have said that plastic rings may crack over time although I have no evidence for this assertion. A friend of mine has been using the same set of polycarbonate rings in his wheels for 7-years now and they show no evidence of wear or cracking. Also, the plastic rings are marginally lighter than those made from aluminum.
Before installing in the wheel, coat the outer surface of the ring with spark plug anti-seize and insert fully from the inner side of the centerbore. They are a light push fit (only finger pressure necessary) and when fully home the flanged outer surface of the ring will be below the wheel mounting face so that the face will be flush against the hub when drawn up tight by the lug nuts. Coating the outer surface of the ring will make it easier to remove from the wheel over time should the need arise. Of course, when mounting the wheel to the hub, also coat the hub and/or the inside of the ring where it contacts the hub with anti-seize, to ensure easy removal when necessary. Before actually mounting the wheel, be careful the rings don't fall out and get misplaced.
Happy Motoring!
Photo 1 illustrates the set of rings used to mount the Enkei OR52 wheels to my car. The rings are marked 72.6-54.1 (72.6 mm being the centerbore diameter of these wheels) and were provided to me by Discount Tire when I ordered the wheel/tire combo from them.
Photo 2 shows the wheel centerbore before the hub ring has been installed.
Photo 3 is of the same wheel with the hub ring seated.
Photo 4 portrays a set of hub rings similar to the ones used to mount the 5Zigen FN01R-C wheels to my car. Note they are marked 73 x 54.1 (73 mm being the centerbore diameter of the 5Zigen wheels).
Apparently, some car enthusiasts are not aware of the crucial importance of using hub rings when installing aftermarket wheels. In fact, some don't even know of their existence. Since this is an extremely important topic affecting both handling and safety concerns for our cars, I thought it a good idea to ensure that more of our members have access to this information.
Why Hub Rings?
OEM alloy and steel wheels are manufactured to have a centerbore diameter exactly sized to match that of the vehicle hub. This ensures that the wheel is solidly supported by the hub, giving what's called a hubcentric mounting. Here, the lugs and lug nuts function to hold the wheel to the hub, but do not support its weight. The lugs are not designed to be a weight-bearing component by themselves - their primary function, in conjunction with the lug nuts, is to solidly fasten the wheel to the hub assembly.
By contrast, most aftermarket wheels (except those specifically designed for a specific model; in which case the centerbore is matched to the vehicle hub size) are made with a centerbore diameter much larger than most vehicle hub diameters. This enables a single aftermarket wheel type to fit a wide variety of cars and models. If such a wheel is mounted on the car, it will only be supported by the lugs (called a lugcentric mounting) giving rise to possible movement between wheel and hub during cornering and acceleration, vibration, and excessive wheel bearing wear, including possible structural failure of the lugs themselves. The problem is made even worse when fitting a wheel of less positve offset than OEM design because it places an additional strain on the wheel bearings and lugs.
To provide the desired hubcentric mounting of aftermarket wheels, hub rings are employed. The inner diameter of the hub ring is sized to just fit over the car's wheel hub (slip fit) while the outer diameter of the hub ring is sized to fit the wheels centerbore (slip fit or light push fit). So installed, hub rings enable the correct hubcentric mounting of any aftermarket wheel. For those of you who minimize the importance of hubcentric mounting, TheMAN has pointed out that no Japanese car is designed to use lugcentric mounting; why should the wheels on your car use an inferior method of attachment as compared with OEM?
In order to select the correct size hub rings, we have to know both the hub diameter of our car and the centerbore diameter of the aftermarket wheel in question. If a listing can't be found for your vehicle's hub diameter, it's easy enough to measure this dimension on your own. A decent caliper or micrometer (2" to 3" range for most purposes) will easily do the job. Once the hub diameter is known, select a ring whose i.d. matches it and you're all set.
Hub Diameters
All 4-lug Proteges: 54.1mm
All 5-lug Proteges: 67.1mm
323 ('86-'89): 59.61mm
323 ('90-'95): 54.1mm
MX3: 54.1mm
3: 67.1mm
626 ('83-'92): 59.61mm
626 ('93-'02): 67.1mm
Millenia: 67.1mm
6: 67.1mm
MPV: 67.1mm
5: 67.1mm
Thanks to firelizard for providing a number of the hub dimensions listed above.
Finding Centerbore Diameters
Centerbore diameters vary greatly depending on the manufacturer. Some manufacturers, for example Enkei, list centerbore diameters on their website; most, but by no means all Enkei centerbores are 72.6 mm.
Others such as 5Zigen do not. Again, in the absence of a listing, the centerbore diameter can be determined using a caliper or inside micrometer. I know the FN01R-C wheels have a 73 mm centerbore because I measured it myself. However, that doesn't necessarily mean all their wheels have this same dimension.
Rota fans are fortunate because a Canadian website lists the centerbore diameters of all their wheels.
When you buy wheels online, some dealers will provide the correct hub rings as long as they know your car model, relieving you of the task of discovering the dimension on your own. Hub rings can also be bought separately from a variety of sources.
Installing Hub Rings
Hub rings are available in both polycarbonate plastic and aluminum. I use aluminum types because some have said that plastic rings may crack over time although I have no evidence for this assertion. A friend of mine has been using the same set of polycarbonate rings in his wheels for 7-years now and they show no evidence of wear or cracking. Also, the plastic rings are marginally lighter than those made from aluminum.
Before installing in the wheel, coat the outer surface of the ring with spark plug anti-seize and insert fully from the inner side of the centerbore. They are a light push fit (only finger pressure necessary) and when fully home the flanged outer surface of the ring will be below the wheel mounting face so that the face will be flush against the hub when drawn up tight by the lug nuts. Coating the outer surface of the ring will make it easier to remove from the wheel over time should the need arise. Of course, when mounting the wheel to the hub, also coat the hub and/or the inside of the ring where it contacts the hub with anti-seize, to ensure easy removal when necessary. Before actually mounting the wheel, be careful the rings don't fall out and get misplaced.
Happy Motoring!
Photo 1 illustrates the set of rings used to mount the Enkei OR52 wheels to my car. The rings are marked 72.6-54.1 (72.6 mm being the centerbore diameter of these wheels) and were provided to me by Discount Tire when I ordered the wheel/tire combo from them.
Photo 2 shows the wheel centerbore before the hub ring has been installed.
Photo 3 is of the same wheel with the hub ring seated.
Photo 4 portrays a set of hub rings similar to the ones used to mount the 5Zigen FN01R-C wheels to my car. Note they are marked 73 x 54.1 (73 mm being the centerbore diameter of the 5Zigen wheels).
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