The Stovebolt Site Forums The Parking Lot Big Bolts Adapters for 20 in. to 22.5's

I've seen a couple of dodge duallys running around town with 22.5 wheels and tires.I've heard about adapters that can be used on the 5/10 lug pattern of the Bigbolts to the pattern of 10 lug 22.5.Has anyone else heard about or seen these adapters? Where can we get them?

I seriously looked into making some a few years ago, but in my opinion there is not enough room to make it work.

The small 8 lug like pickups to big 10 lug works OK because the bolt circles are different enough to make room for studs and nuts.

The 7.25" 10 lug up to 11.25" doesn't leave enough room for the two bolt patterns to exist in the same adapter.
At least that's what I decided after trying several different ways to draw it in auto-cad with no apparent and safe solution.

Grigg

So you don't think that going from a small 10 pattern to a big 10
pattern would work? Ok by me,I just thought something was doable.

Just because I couldn't figure a good way doesn't mean you can't try, and if you do figure out a way please let us know.

Grigg

Try this guy here:

http://www.chromewheel.com/index.html

He quoted me the same adapters that are hubcentric for both bolt patterns for $740 a set. Guy's name is Bernie. Phone is 713-644-0497.

I have a question in regards to these adaptors. How does the wheel offset work with the adaptors and the wheel itself? The link that Fclaridge listed had a truck that I think is a member on this site. See here. This truck is on an 82 frame but the fenders appear to cover the wheels. If the adaptors and wheels have the right offset it would help the appearance of my truck and bring the wheels in under the fenders. I have thought about these adaptors for a while but they are expensive to purchase just to try out or to take some measurements. Any help would be appreciated.

Which adapters exactly?

Originally this thread was about 10 lug on 7.25" circle adapted up (if possible) to semi truck 10 lug size.

I get the feeling you're asking about 8 lug pickup truck adapted up to semi truck size?

Whoever sells the adapter should have an exact answer on the difference, if any, in track with (or wheel mounting surface offset) with the adapters. With that info you can look at the wheels you may want to use and decide if they fit in the fenders or not; you can calculate exactly where they sit.


Grigg

The adapters I was referring to are the 10 lug 7.25" going to a modern semi 10 lug circle. I specifically gave the vehicle info for my 56 Chevy 1.5 ton and he said he had them for $740.

Here is what I sent him in an email, with his response:

I saw your website and wanted to know how the 1956 Chevy Flatbed dually was converted for the updated wheels. I am planning a similar upgrade and really like your products. I appreciate the help. My vehicle is a 1956 1.5 ton truck chassis. 5 lug front wheels with drum brakes. I want to convert over to disc brakes and somehow get to the 10 lug 22" or 22.5" wheels with low pro tires. Let me know what is possible for me to do. I really like what you did with that flatbed on your site.

His response:

YES WE HAVE THOSE ADAPTERS THEY ARE 740.00 A SET OF 4

FOB HOUSTON

BERNIE

713-644-0497

It would be good for people interested to ask more questions specifically relating to their own vehicle and what they are trying to accomplish so they get the proper fitment.

You're saying that this guy has adapters to go from a 7.25 bolt circle to what ever it is on a 22.5 tubeless wheel currently being used today.
The center circle you have is 5.25, right ?
Do you know how thick the adapters are and if that added spacing outward will be a problem.
Dan

Current production hub pilot wheels are specified in metric but they measure approximately 8 11/16 bore on an 11 1/4 bolt circle. I just can't picture an adapter to make this work. Are you sure the guy you spoke to understood what you are trying to do? I would make sure that you get something in writing from him that you want an adapter to go from a hub with a 5.25 bore and 7.25 bolt circle to a 220 mm bore and 285.75 mm bolt circle before I would plunk down any money.

OK, I just emailed Bernie again to get some further calrification and some specs for spacing and offset. Also asked for a picture. I hope to get more info in the next couple of days. When I do I will post right away.

Looking at the math real quick it looks possible.

For the 10 on 7.25" it is 2" from the edge of the bore to the center of the stud.

From the center of the inner stud to the edge of the outer bore it is 1.41".

Then from the edge of the outer bore to the middle of the outer stud it is another 2.56".

So if I look at these number correctly it may very well be possible. I know I would like to see a picture of one and get a schematic drawing of one to be sure.

Will someone check my math and see what they think?

For calculating:

Small GM 10 lug pattern, 7.25" bolt circle, 5.25" center hole, (older trucks use 4.75", check yours)

Most common Semi truck 10 lug hub piloted 10 Hole on 285.75mm Bolt Circle with a 220mm center hole.

Narrow (reasonably) 22.5" semi truck steel wheels you may consider are Accuride part # 29001, have 5 hand holes, rim width of 7.5", and wheel offset of 6.44"
Also check out aluminum ones part # 28844Axx (substitute "xx" for NP, OP, IP, BP for different polish options)

What you also need when designing the adapters is the OD of the hub flange for both hubs, or if flat on the back you'll at least need the OD of the semi truck hub to mimic for the adapter overall diameter.

Also take into consideration the stud and nut size for both (5/8-18 and M22 x1.5), and the OD of the socket you'll use on the inner nuts.

I'll try to find the drawing I made up a couple years ago before decided the fasteners wouldn't work being so close to (overlapping?) each other. If this works at all it'll be close, and will be the first to say I was wrong.

Grigg

Yes Grigg, I used those measurements. For the modern semi wheels I used 285 mm bolt circle and the 220 mm for the bore, just converted to standard measurements. I did get a response from Bernie:

the adapters are .850 thick and that would be offset.

the adapters are very similar in looks to a 8 hole Chevy that is all over the web, just there is 10 holes in the plates.

I asked him if he had a CAD drawing showing the specs. I think that would be helpful too before plunking down $740 for a set of these.

Then I plan on going the simple route first and get a set of steel wheels before I step up and get aluminum. I'll do the math on the cost difference though. I can get steel wheels for cheap though.

Fred

I agree with your math, and this ~1.41" is as large as the flange on the inner nut can be. With a normal flanged wheel nut this will interrupt the pilot portion for the larger wheel. Having an interrupted pilot diameter is not a problem, but having the flange of the nut interfering with the larger wheels bore diameter is.

You can probably use normal nuts that are about 1-1/16" on the flats, or just under 1.25" on the corners? I expect this will work. You may not be able to remove the adapter once the larger wheels are in place, a socket may not fit because of the larger wheel.

Grigg

Many of the steel wheels you find with this large 10 lug pattern will be 8.25" wide. As far as I know 7.25" is as narrow as you can find, but you may have to do some searching to find narrow used ones.

Grigg

I chatted with Bernie a bit more and I think when I get my taxes back I will order a set of these adapters. He gave me a bit of his background as well and I feel lots more comfortable getting them now. He also has a lifetime warranty for them. This is the direction I want to go and get 22.5" or even 24.5" wheels and low profile radial tires for my bus. Going to keep the drum brakes while I research how to convert to discs for this size of chassis.

I apologize to the original poster for somewhat thread-jacking his post. I hope we got somewhere he was intending on going with our discussion. I know I did.

Thanks everyone and especially Grigg for the help.

Fred

I do thank you for the thead jacking-Please take my wallet,kids ,wife,and dog but don't take my truck.
You went just where I needed to go thanks for all the info,now all I need to do is get some money together.

From what you guys say it looks as though this adapter will work.
With just over 3/4 in outward spacing the hub will look set in and the spacer will show.
I'm curious to see what it would look like.
Four years ago I had an adapter made for one of my tractors so I could use present day wheels on it. The inset and look of the adapter did not look too cute so I made hub cover to hide the whole thing which looked a whole lot better.

I spose it's just wishful thinking but I wish I could get a blank, not drilled 22.5 wheel and take it to a shop and have it drilled for 4.75 center, 7.25 bolt circle and retain the stock look.
Dan

I've looked into that too.
Accuride either doesn't have blank ones to sell (might be punched before forming?), or doesn't want to sell blank centers.

Even if they did the closest thing they have would look exactly like those wheels fabricated by Stockton wheel and pictured in another thread. They'd have a larger than normal flat surface around the bolt pattern, enough to look odd.
(not that wheel adapters and ~11.25 bolt circle wheels won't...)

I did find a wheel manufacturer that made special wheels for equipment and railroad trucks among other things. And at the time they were willing to help me and sell blank centers. Problem is their centers don't look like normal truck wheels, the contour of the dished center was different than we're use to seeing.

Grigg

Glad it worked out for you too PapaJ. The same guy that does these adapters machines his own custom wheels as well. You could try him for that too. I am not interested in keeping a relatively stock look with the wheels. They make center hole covers to dress the wheels up nicely so I am not worried. One other thing I am considering before I get the package is looking at the Michelin X one tires for the rear. One wheel and tire replaces the set of duals in the rear. So for my application it would be cool to make the bus look a little bit like a pro street set up.

Here is a link to a Chevy Kodiak with 22.5s and the supersingles in the back:

http://www.chromewheel.com/PIX/kodiak.htm

And the wheels are the look I would like too.

Here is a link to what these adapters would look like.

[IMG]http://i107.photobucket.com/albums/m290/fclaridge/WheelAdapter.jpg[/IMG]

Is that picture an 8 lug version on a new Chevy pickup?

Grigg

Yes, I believe it is the 8 lug to 10 lug conversion.

How far out does that adapter push the centerline?

Judging from the pic, plus drawing straight lines across the face of the rotor and the face of the adapter it looks to be the distance of 2 to 3 rotor thicknesses.
I would expect the rotor to be at least 1 in thick, so my guess is 2 to 3 inches.
I think the truck will now have that new wide-track stance. That was popular and a selling point for Pontiac back in the 60's

Will the tires still be inside the fenders, or will fender flares be needed ?

Dan

Here is what Bernie said about their thickness:

the adapters are .850 thick and that would be offset.

the adapters are very similar in looks to a 8 hole chevy that is all over the web , just there is 10 holes in the plates

The picture I posted is only a reference, not the actual 10 to 10 conversion we need.

okay who makes an adapter for 8-6.5 to an chevy split rim 20" or a 22.5 " rim.looking t put 20 or 22.5s in the rear of one of my factory r90(18"wheeel) truck.any help out there??

Try Bernie at

http://www.chromewheel.com/

He should be able to help you out.

Fred

Hey guys. If you are interested in changing over to modern 22.5 wheels be sure to really measure your rig and go over the clearances. I really wanted to go to 22.5's, but I measured the fender opening length and compared it to the overall diameter of the tires I could use and it will not work. So I compared it to the sizes in the 19.5 tires and it works and will allow me to put a 2" drop on the bus all the way around. Glad I thoroughly checked before putting out the expense for something that would fit my rig. Given this situation, I now have more options for converting over to disc brakes. I have found several places that will help me do this. One place in CA said it would run about $1000 though. It's a conversion using the original hubs, updating the bearings and adding a rotor to the hub. A little more progress today. I feel good.

fclaridge,

I'm a little confused. The 22.5" tubeless wheels and tires were designed as a direct replacement fot the 20" tube type. If you have 9.00 x 20" tires the direct replacement would be a 10.00 x 22.5"...they both have the same diameter. If you have 10.00 x 20's then you need 11.00 x 22.5's. As long as the wheels have the same offset your clearences will be the same.

With that said, I have know knowledge on the 19.5" wheels and the disc brake that are available...

Mike B

The way I usually state it is that a 10x22.5 makes about the same revolutions per mile as a 9.00x20 and an 11x22.5 makes about the same revolutions per mile as a 10.00x20. That way no one should get the idea that a 11x22.5 will fit on a wheel designed for a 10x20 and so on.

And the 8.25x20 is about the same outside diameter as a 9R22.5.
Which is about as small as you'll find for modern 22.5 without going to low profile tires.
Although I have seen and owned some 8x22.5 tires and even a 7x22.5 tire, seriously doubt you find new ones in those sizes though.

Grigg

Grigg is right on the sizes of 22.5 tires in fact when I bought the 10.00x22.5 for both my 56 and my 64, I found that 9.00x22.5s' although fairly common come in very limited tread patterns. It seems that 9.00x22.5s’ in a traction tire are a very rare critter however I believe that it worked out for the better.

I wouldn't say rare, but the selection is not as great. I had no problems finding them when I looked.
Try a good year G164 tread.
http://www.goodyear.com/cfmx/web/tr...odline=160708&webprodline=G164%20RTD
well they did offer them in 9R22.5, although that link doesn't show it.
Also G622 http://www.goodyear.com/cfmx/web/truck/line.cfm?prodline=160723

Try TOYO M-608Z 9R22.5 G14
http://www.tiresdirect.net/TOYO_M-608Z_9R22_5_G14_P3591C282.cfm

There are others out there too, and don't forget retreads, some are really aggressive.

Grigg

I went out and measured them again after reading the posts here. My stock tires are 7.50x20 and measure about 35" overall. Anyone have the correct specs on this tire size? That would be most helpful. All of the 22.5's I have looked at have been a minimum of 38" in diameter, 38.2" for the Michelin XRV 255/80/22.5. So still bigger than what can fit under my fenders. Unless I am looking at things wrong.

How about some 245/75R22.5 tires?
These are all the Goodyear tires in that size.
http://www.goodyear.com/cfmx/web/truck/search.cfm
37", 37.1" or 37.6" depending on the tread style, and about 9.5" wide.

Or some G670 in 255/70R22.5 at 36.4".
If you can fit another 3/4" radius on your current tires these may fit? Do you have more than 3/4" between tire and fenders during all suspension travel?
But they are about 10" wide, need to account for that too.
Also note that if they were bald they would be 1" shorter yet, and bald tires are cheaper tires

Grigg

For those of you with smaller tires ,say 7.00 or so,the 19.5 will work,of course always check with your local tire shop as I did mine,although the tallest 19.5 did'nt look right for my application,it might work for you.

I think what will work is the 19.5's and that will allow me to lower the bus a couple inches so the bottom step isn't 10 inches off the ground. But with so many variables and such I think I will get the beast moved onto a hard surface and do some more measuring. I might ultimately find a P30 step van with disc brakes and just buy the whole thing and do a frame off or total frame swap. So much to think about with these big guys. Maybe I won't be getting her running to be ready for summer. Not that looking pretty was the plan this year, but I would like to at least like to drive it. I really appreciate all the input and feedback here guys. Especially Grigg. Been reading his tech pages over and over for more insight and it is most helpful.

hey fclaridge we should try and get together sometime we live just a few miles apart