hub centric vs lug centric
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Hotshot
Joined: Feb 2004
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From: The Shenandoah Valley
hub centric vs lug centric
About the "hub centric or lug centric" deal ... it is much "over rated" IMHO.
I don't recall ever seeing a wheel that fits over these truck's front hubs fit anywhere near hub centric on the rear axle's center hub ... nor even actually tightly on the front 4x4 hub? Reason I mention it, I see it come up elsewhere often enough and think back on my experiences.
I don't mind hub centric as long as there is enough room that the wheels don't get stuck on the hub (which I'ver seen on a police car at 2 AM when trying to change a flat on the shoulder of a cold wind swept interstate highway at which time I wouldn't have given a rat's *** for hub centric, was a OEM steel wheel on a police car stuck fast) ... but except for factory wheels, I don't recall an aftermarket wheels I've bought having "hub centricity", rather they were "lug centric". We even drag raced with lug centric and unilug wheels often enough. To my way of thinking, hub centric might help lining up wheel bolts (a "sucky" idea they are too)that thread into a vehicle's hub or axle flange, but hub centricity really has no value to speak of with lug studs and threading nuts with conical seats in place. If lug nuts won't properly secure a wheel in place, then they are a hazard anyway. If hub centric is for balance, why are they then fitted loose enough to allow removal. The cone seat lug nuts (or bolts even) will draw the wheel into a precise position ... every time with no clearance tollerance.
I don't recall ever seeing a wheel that fits over these truck's front hubs fit anywhere near hub centric on the rear axle's center hub ... nor even actually tightly on the front 4x4 hub? Reason I mention it, I see it come up elsewhere often enough and think back on my experiences.
I don't mind hub centric as long as there is enough room that the wheels don't get stuck on the hub (which I'ver seen on a police car at 2 AM when trying to change a flat on the shoulder of a cold wind swept interstate highway at which time I wouldn't have given a rat's *** for hub centric, was a OEM steel wheel on a police car stuck fast) ... but except for factory wheels, I don't recall an aftermarket wheels I've bought having "hub centricity", rather they were "lug centric". We even drag raced with lug centric and unilug wheels often enough. To my way of thinking, hub centric might help lining up wheel bolts (a "sucky" idea they are too)that thread into a vehicle's hub or axle flange, but hub centricity really has no value to speak of with lug studs and threading nuts with conical seats in place. If lug nuts won't properly secure a wheel in place, then they are a hazard anyway. If hub centric is for balance, why are they then fitted loose enough to allow removal. The cone seat lug nuts (or bolts even) will draw the wheel into a precise position ... every time with no clearance tollerance.
Laughing Gas
Joined: Sep 2018
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I can not speak in great detail because I do not know all the information such as manufacturing cost, part life, or what the limiting factors of the strength analysis are but I will throw out my guess.
I imagine it is because hubs on newer cars are smaller and require the load path of the vehicles mass to be more directly transfered into the hub.
My 79 f250 axle has a 1/2 wheel stud and f350s run a 9/16 stud.
It looks like a 2015 f350/f450s run a m14 (9/16ish) stud.
The difference is the 2015 super duty is rated to pull/haul way more than my truck. My truck is closer to the new 1/2 ton f150 ratings.
I imagine it is because hubs on newer cars are smaller and require the load path of the vehicles mass to be more directly transfered into the hub.
My 79 f250 axle has a 1/2 wheel stud and f350s run a 9/16 stud.
It looks like a 2015 f350/f450s run a m14 (9/16ish) stud.
The difference is the 2015 super duty is rated to pull/haul way more than my truck. My truck is closer to the new 1/2 ton f150 ratings.
Moderator & parts slinger
Joined: Feb 2007
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From: S/W Missouri, Polk county
All I know is I got a smoking deal on some 2006-2009 2nd gen H2 rims (17's) and they had some brand new 315/70/17 BFG AT's. I was going to put them on my 99 Dodge 2500. Both applications are 8 on 6 1/2 just like our older F250's.... But come install time the center hub hole on the rims is just a tad to small to fit my Dodge. I would have to get it machined out to make them fit.
And I read on some Dodge sites that this specific application was hub centric and not lug centric. And if you if you did not get them machined out just perfect you can almost never get the rim to balance.
That is why AFAIK 8 on 6 1/2 F250 rims fit a 3/4 ton Dodge and the other way around. And Ford fit a chebby but chebby does not always fit a Ford/Dodge due to the smaller hub center hole of their rims. Again AFAIK.
I seen a recent pic on here of some 3/4 ton Dodge rims on a 76 HB and asked the guy if it was a simple swap out.
And I read on some Dodge sites that this specific application was hub centric and not lug centric. And if you if you did not get them machined out just perfect you can almost never get the rim to balance.
That is why AFAIK 8 on 6 1/2 F250 rims fit a 3/4 ton Dodge and the other way around. And Ford fit a chebby but chebby does not always fit a Ford/Dodge due to the smaller hub center hole of their rims. Again AFAIK.
I seen a recent pic on here of some 3/4 ton Dodge rims on a 76 HB and asked the guy if it was a simple swap out.
Laughing Gas
Joined: Sep 2018
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Swapping wheel on newer vehicles can be challenging.
I always cringe when I see see a new 3/4 plus truck hauling a heavy load with aftermarket wheels. You have to wonder if they have the hub centric adapters. Also, have you ever tried to get the load rating of a rim? Only the reputable companies usually provide that info.
I guess I do not see news stories of broken rims causing accidents so maybe I am just being to careful.
I always cringe when I see see a new 3/4 plus truck hauling a heavy load with aftermarket wheels. You have to wonder if they have the hub centric adapters. Also, have you ever tried to get the load rating of a rim? Only the reputable companies usually provide that info.
I guess I do not see news stories of broken rims causing accidents so maybe I am just being to careful.
Cargo Master
Joined: Nov 2007
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Hub centric rims are supported by the hub flange and transfer the load directly to the hub/bearing assembly. If a lug nut loosens up or snaps the wheel is still fully supported. They also tend to run truer to the hub, which generally improves ride harshness.
Lug centric rims transfers all the wheel load through the clamping force from the stud and nut between the wheel and it's mounting surface. If a lug nut loosens or snaps, the remaining lug nuts need to provide the extra clamping force to support the load. If they can't provide enough clamping force and the wheel slips, it can shear the remaining lugs. Lug centric rims can be hit or miss on how true they run. Usually it's not an issue and can be balanced out.
I'm a fan of hub centric rims. As long as they're cleaned and never siezed every time they are mounted it shouldn't be an issue. But there's nothing wrong with lug centric either. I just mounted some lug centric adapters on my old beater GMC so i can run later model rims and I'm not gonna be afraid to load her up every now and then. But i also check the lug nut torque on them regularly.
Lug centric rims transfers all the wheel load through the clamping force from the stud and nut between the wheel and it's mounting surface. If a lug nut loosens or snaps, the remaining lug nuts need to provide the extra clamping force to support the load. If they can't provide enough clamping force and the wheel slips, it can shear the remaining lugs. Lug centric rims can be hit or miss on how true they run. Usually it's not an issue and can be balanced out.
I'm a fan of hub centric rims. As long as they're cleaned and never siezed every time they are mounted it shouldn't be an issue. But there's nothing wrong with lug centric either. I just mounted some lug centric adapters on my old beater GMC so i can run later model rims and I'm not gonna be afraid to load her up every now and then. But i also check the lug nut torque on them regularly.
Lead Driver
Joined: Oct 2018
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All if not nearly all older vehicles were lug centric. they worked fine then and still do.
The only draw back to lug centric is many tire shops with new equipment don't have the adapters to properly balance some bolt patterns.
The only draw back to lug centric is many tire shops with new equipment don't have the adapters to properly balance some bolt patterns.
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