Options for "pushing out" rear wheels
Thread Starter
Burning Brakes
Joined: Mar 2011
Posts: 862
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From: Communist party of MD
Options for "pushing out" rear wheels
My '69 came with fender flares and had 15x10" really rear wheels. I didn't like the Rally wheels and sold them after I picked up a set of '82 corvette 15x8 alloys. Once I put them on the car, the rears were sitting way inside the fender. So I had some custom made 2" adapters fabricated from a machine shop in NV. Installed them and they look great.
I recently had some work done at a local hot rod shop and the owner warned me about the adapters saying he's had customers lose wheels, crash into ditches, etc from the adapters failing. I also heard that it puts too much stress on the rear wheel bearings.
What are my options to push out the rear wheels safely?
-Offset trailing arms? But don't these keep the bearing in the same location and only ebables you to put wider tires on with?
-New wheels? I really don't want to change the wheels as I like my '82 slotted wheels.
-hub centric adapters? My adapters are hub centric on the hub, but not the wheels themselves.
Please help, thanks!
Here is a test fitment of the '82 wheel before I had the tires mounted on. Sits way too much on the inside of the fender.
The adapters I had custom made.
How the 15" x 8" wheels sit after the adapters were mounted (how they should be, flush with the top of the fender).
I recently had some work done at a local hot rod shop and the owner warned me about the adapters saying he's had customers lose wheels, crash into ditches, etc from the adapters failing. I also heard that it puts too much stress on the rear wheel bearings.
What are my options to push out the rear wheels safely?
-Offset trailing arms? But don't these keep the bearing in the same location and only ebables you to put wider tires on with?
-New wheels? I really don't want to change the wheels as I like my '82 slotted wheels.
-hub centric adapters? My adapters are hub centric on the hub, but not the wheels themselves.
Please help, thanks!
Here is a test fitment of the '82 wheel before I had the tires mounted on. Sits way too much on the inside of the fender.
The adapters I had custom made.
How the 15" x 8" wheels sit after the adapters were mounted (how they should be, flush with the top of the fender).
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I'm not sure why you would have an adapter made since they are a common purchasable item.
I bought the MidAmerica 2 inch adapters and raised hell with them for about 5-6 years with 11 X 17 rear wheels. later as tech inspection rules changed I had them modified to the larger studs.
Wheel bearings are replaceable, but i have not had any problems
I bought the MidAmerica 2 inch adapters and raised hell with them for about 5-6 years with 11 X 17 rear wheels. later as tech inspection rules changed I had them modified to the larger studs.
Wheel bearings are replaceable, but i have not had any problems
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Sure there is. He could have the stock aluminum wheels widened by 2" (on the back side), use the 2" adapters to put the effective BS back to ~4", and then fill those oversize wells with 295/50R15's. In addition to looking very cool, that would also put the rear track width (at wheel CL) much nearer to stock, reducing any adverse bearing loads.
In any event, I'd suggest attaching wheel adapters to the original stubs with HD 1/2" studs, as this type of system doubles the chance of a lug bolt related failure. Also, with purchased (as opposed to custom fabricated) adapters, you'll have someone to blame (read, "sue") if something goes wrong with one.
TSW
Last edited by TheSkunkWorks; Dec 21, 2012 at 08:15 PM.
Race Director
Joined: Jan 2007
Posts: 14,976
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From: NYC NY
Sure there is. He could have the stock aluminum wheels widened by 2" (on the back side), use the 2" adapters to put the effective BS back to ~4", and then fill those oversize wells with 295/50R15's. In addition to looking very cool, that would also put the rear track width (at wheel CL) much nearer to stock, reducing any adverse bearing loads.
TSW
google Weldcraft and check out their website. Others on this forum have used them with great success.
Le Mans Master
Joined: Aug 2010
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put these on the rear of my C4, when I went to C6 Z06 wheels, hub-centric is alot safer due to your wheel being supported by the hub and lugs instead of just the lugs. you'll probably hear a lot of opinions.
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Le Mans Master
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From: Graceland in a Not Correctly Restored Stingray
Melting Slicks
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From: Peoria Arizona
Melting Slicks
Joined: May 2002
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From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
If you doubt the spacers you have take a look at the Willwood wide 5, 2" spacers for racing and than look at what you have.
there are no issues with the spacers,
Neal
there are no issues with the spacers,
Neal
Le Mans Master
Joined: Aug 2010
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this is a 'Wilwood" wide 5, 2" spacer, for a limited application on smooth race tracks. they dont recommend them for the street where there's potholes, speed bumps. etc. although I'm sure they probably get used there. With the large inset that are around the lug bolts in the op's picture, it seems that if he hit a pothole hard enough, he could knock the wheel off center, and if he hit hard enough, he could shear lug bolts off. Thats where a 'hubcentric' adapter has the advantage. The hubcentric not only sits inside the wheel, but the oe hub sits inside the adapter providing a solid mount. I've seen the version in the op's picture, 'shear lugs', more than once. As cheap as the hubcentrics are, there's no reason not to be abit safer
hope this helps
Melting Slicks
Joined: May 2002
Posts: 2,717
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From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
this is a 'Wilwood" wide 5, 2" spacer, for a limited application on smooth race tracks. they dont recommend them for the street where there's potholes, speed bumps. etc. although I'm sure they probably get used there. With the large inset that are around the lug bolts in the op's picture, it seems that if he hit a pothole hard enough, he could knock the wheel off center, and if he hit hard enough, he could shear lug bolts off. Thats where a 'hubcentric' adapter has the advantage. The hubcentric not only sits inside the wheel, but the oe hub sits inside the adapter providing a solid mount. I've seen the version in the op's picture, 'shear lugs', more than once. As cheap as the hubcentrics are, there's no reason not to be abit safer
hope this helps
An aluminum adapter with the hubcentric lip can't be much stronger than the one without it. The shear resistance of an 1/8" lip of aluminum is rather low if I had to guess. I do agree it does help with centering the wheel while tightening the lug nuts.
The shear strength of the lugs are rather high (I've looked them up but don't remember them off the top of my head). Many factory vehicles have left the factory without hubcentric wheels.
I'm no expert on wheel adapters and will admit I've only seen a few vehicles with them and I've never seen a failure on a vehicle due to the adapter.
I did have a couple of our Mechanical Engineers look at them prior to me installing them on my car. The only recommendation was if I was concerned to clean the mating surfaces and use Loctite during the install.
I've herd of one failure here on the forum and I believe it was due to loose lug nuts.
I would imagine the clamping forces of the 5 studs is way beyond the shear protection of the 1/8" aluminum lip.
all good discussions
thanks
Neal
Pro
Joined: Nov 2009
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From: Milpitas Calyfornua
295's are too large on 8 inch wheel, and may look better from rear of car as they will not stick out beyond fender lip as in your posted photo. I recently installed 275's on rear of my 71,,,255's on front. Checked this out carefully, 295's not recommended for BFG anyhow.
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
The correct lug nuts have to be used with the wheels. Hitting a pot hole will not change the centering of the wheels if all is correct (loose or incorrect lugs). The relief around the lugs actually reduces the shearing effect on the stud.
An aluminum adapter with the hubcentric lip can't be much stronger than the one without it. The shear resistance of an 1/8" lip of aluminum is rather low if I had to guess. I do agree it does help with centering the wheel while tightening the lug nuts.
The shear strength of the lugs are rather high (I've looked them up but don't remember them off the top of my head). Many factory vehicles have left the factory without hubcentric wheels.
I'm no expert on wheel adapters and will admit I've only seen a few vehicles with them and I've never seen a failure on a vehicle due to the adapter.
I did have a couple of our Mechanical Engineers look at them prior to me installing them on my car. The only recommendation was if I was concerned to clean the mating surfaces and use Loctite during the install.
I've herd of one failure here on the forum and I believe it was due to loose lug nuts.
I would imagine the clamping forces of the 5 studs is way beyond the shear protection of the 1/8" aluminum lip.
all good discussions
thanks
Neal
An aluminum adapter with the hubcentric lip can't be much stronger than the one without it. The shear resistance of an 1/8" lip of aluminum is rather low if I had to guess. I do agree it does help with centering the wheel while tightening the lug nuts.
The shear strength of the lugs are rather high (I've looked them up but don't remember them off the top of my head). Many factory vehicles have left the factory without hubcentric wheels.
I'm no expert on wheel adapters and will admit I've only seen a few vehicles with them and I've never seen a failure on a vehicle due to the adapter.
I did have a couple of our Mechanical Engineers look at them prior to me installing them on my car. The only recommendation was if I was concerned to clean the mating surfaces and use Loctite during the install.
I've herd of one failure here on the forum and I believe it was due to loose lug nuts.
I would imagine the clamping forces of the 5 studs is way beyond the shear protection of the 1/8" aluminum lip.
all good discussions
thanks
Neal
Last edited by oldalaskaman; Dec 24, 2012 at 09:21 AM.
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
295's are too large on 8 inch wheel, and may look better from rear of car as they will not stick out beyond fender lip as in your posted photo. I recently installed 275's on rear of my 71,,,255's on front. Checked this out carefully, 295's not recommended for BFG anyhow.
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Ran the BFG 295's for at least 10 years on stock Rally rims... not a single issue with the tires/rims/bearings or handling.
Melting Slicks
Joined: May 2002
Posts: 2,717
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From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
you brought up the 'wilwood', that arent recommended for street use, but that I think are safer than the ones the op posted due to clamping force location, and just the fact that they are made by 'wilwood'. I think you make some good points, but in my 40 plus years playin with other folks mistakes, I've seen them sheared off, probably for some of the reasons you mention, and the hub-centrics arent 1/8" at least mine arent, I havent measured them but, mine are almost 1/2" and a good 1/4" thick, its quite a bit more depending on maker , of course, the real cheap ones probably being less. Why argue against the op being a bit more safe? He probably has his family in the car with him at times. even if it was just me in the car, I wouldnt run those adapters he has in his picture. When I post here its from personal experience , not something I read or asked an engineer about. Adapters work, I dont like them but I use them cause I cant afford spendy wheels, but because of the insets around the lugs on the op's , I dont think they are the best to use. I've actually seen it, hope this helps.
Neal