Help with 22.5 Wheels/Tire size

[JPBrecheisen]

All,

Need help trying to figure out if an 11R22.5 tire will fit with these wheels on a 1960 C60. It currently has 8.25-20 bias ply rubber with the widow maker RH-5 two-piece split rims.

Upgrading to 22.5 steel wheels. The "stock" width is 6.75 which you can only run a 10R22.5 on. The wheel builder says they can make 7.5 or 8.25 widths on request to run the 11R22.5 size tire. I'd like the larger tire as I have a single speed rear end and would like to be able to run at 55-60 without turning the engine near 3000 RPM.

I am afraid the rear dual set up will not clear either the leaf springs and/or they tire/wheel combo will touch each other once the duals are bolted together.

jumpsoffrock bought a set of the aftermarket 28160 wheels and I am tracking the issue with the lug holes.


Thanks for the help.

[1976gmc20]

Those old wheels aren't that hard to change and not dangerous if you do it right.

It's up to you though ....

[JPBrecheisen]

Originally Posted by 1976gmc20

Those old wheels aren't that hard to change and not dangerous if you do it right.

It's up to you though ....

Yeah, I personally had never messed with them before, but that's my understanding of them as well. Long as they aren't corroded, worn, or warped from running on a flat, they can be done by someone that knows what they're doing.

Honestly, the 20 inch rubber options aren't really there and I think I'll not mind updating to radial rubber.

I would like to run taller tires, but not sure they'll fit on the rears.

[greywuuf]

the lock ring multi piece wheel are fairly benign, the rh5 SPLIT ( in the center where you cant see....) present a Much HIGHER risk.

[1976gmc20]

Originally Posted by JPBrecheisen

Yeah, I personally had never messed with them before, but that's my understanding of them as well. Long as they aren't corroded, worn, or warped from running on a flat, they can be done by someone that knows what they're doing.

Honestly, the 20 inch rubber options aren't really there and I think I'll not mind updating to radial rubber.

I would like to run taller tires, but not sure they'll fit on the rears.

The biggest thing with those is when putting them together the two pieces should be "loose" before airing up. Otherwise they are not all the way on and may fly back apart under pressure.

Of course it's also a good idea not to stand over them when airing up, just in case

The rest of it is just knowing how to go about it without wearing yourself out too much. They do require a fair bit of prying and hammering (in the right places). I had a C-50 log truck and had a lot of flats, so I got plenty of experience over the years.

I have no idea what's available in 20" truck tires today. Back then I bought used school bus tires with about 50% tread for $25 each

[jumpsoffrock]

I'm not completely clear on what you're asking. I hope I can help.

But would pictures of my setup help? I couldn't find 11R22.5 for my rims(that's what I wanted), so they got me 235/80-22.5 .
-->Will they fit the rim? The guys at my local tire shop(been same-family ran for 75+ years) said the 11R22.5 should fit(not absolutely will; "should"), but they're overkill and hard to find used(and very expensive new).
-->Will they touch each other? I really don't have experience.....but I just doubt it.
--> Will they touch springs? Don't know, probably not on my truck.

I may try and take my truck by a tire shop the next day I have off and ask them those three questions(they probably can't answer #3). I'll get back to you if I can manage.




Additionally, With my 4-spd(SM420) and a (6.61 Low) (4.86 high):1 rear end gear, I achieve 55mph @ ~2500 rpm. This is verified mathematically, but not on gauges. My speedometer didn't work and is now completely removed from the truck.

I had to change the rear carrier to get those ratios. With my previous high gear (6.51:1) I calculated the 11R22.5 that I was shopping for to barely put me at 55mph @ 3000. I was not satisfied.


Then I bought a used differential carrier.....

[JPBrecheisen]

Originally Posted by jumpsoffrock

I'm not completely clear on what you're asking. I hope I can help.

But would pictures of my setup help? I couldn't find 11R22.5 for my rims(that's what I wanted), so they got me 235/80-22.5 .
-->Will they fit the rim? The guys at my local tire shop(been same-family ran for 75+ years) said the 11R22.5 should fit(not absolutely will; "should"), but they're overkill and hard to find used(and very expensive new).
-->Will they touch each other? I really don't have experience.....but I just doubt it.
--> Will they touch springs? Don't know, probably not on my truck.

I may try and take my truck by a tire shop the next day I have off and ask them those three questions(they probably can't answer #3). I'll get back to you if I can manage.




Additionally, With my 4-spd(SM420) and a (6.61 Low) (4.86 high):1 rear end gear, I achieve 55mph @ ~2500 rpm. This is verified mathematically, but not on gauges. My speedometer didn't work and is now completely removed from the truck.

I had to change the rear carrier to get those ratios. With my previous high gear (6.51:1) I calculated the 11R22.5 that I was shopping for to barely put me at 55mph @ 3000. I was not satisfied.


Then I bought a used differential carrier.....

Thank you for all this information. I do believe its helping. The pics help a good amount as well.

I was told the 28160J wheel that is offered by wheels now, which appears to be what you ended up purchasing comes in the 6.75 inch width. Most tire folks are telling me that a 11R22.5 cannot fit a rim that narrow. It needs to be either a 7.5 or 8.25 width.

Wheels now can make the 28160J in either width per request of the customer, but I am concerned if I go with the wider rim, I will have issues with the tires clearing each other in the rear or the inner tire clearing the leaf spring.

It all depends on the offset they build the rim to I suppose. I asked for a spec sheet on the rim dimensions but they had not sent it yet. Maybe early next week.

Thanks for the pictures and the input. Looks like there is plenty of room between the rear wheels so that shouldn't be a problem. Looks like If I am going to have trouble, it will be on the leaf spring side as that space could get a little tight with a wider rim/tire combination....

I have inquired about a ratio change as well. I have the 261 I6. I'm hoping to sort of split the difference so I can run 55-60 without running the engine so high.

Thanks again.

Jonathon

[JPBrecheisen]

jumpsoffrock....your wheels are the 6.75 width correct?

[jumpsoffrock]

Yes I believe they are...they are standard as to how they are advertised.

[MjrBummer]

Radials would be much nicer. Just think of how much each wheel/tire will be, and how much less overall rotating mass there will be. Should add up to better mileage as well. Also, if I had a blowout on the side of the highway, how many 20" tires will be available to get me back on the road? Handling is also a consideration. I'm seriously considering the 28160J's as well, but the cost of the wheels, $245 a piece, and new tires, has kept me on the fence for now. I was hoping to find a good donor vehicle I can use the axles, wheel, and tires from. I'm not done looking through all the local scrap yards and farms yet either.

Bill

[JPBrecheisen]

Originally Posted by MjrBummer

Radials would be much nicer. Just think of how much each wheel/tire will be, and how much less overall rotating mass there will be. Should add up to better mileage as well. Also, if I had a blowout on the side of the highway, how many 20" tires will be available to get me back on the road? Handling is also a consideration. I'm seriously considering the 28160J's as well, but the cost of the wheels, $245 a piece, and new tires, has kept me on the fence for now. I was hoping to find a good donor vehicle I can use the axles, wheel, and tires from. I'm not done looking through all the local scrap yards and farms yet either.

Bill

All good points. I think the radial tire in the 22.5 size will have its benefits and make the truck a little nicer to drive. I have been talking to the wheel folks and after having some measurements taken, I don't think I can run anything wider than the 6.75 width. Probably just stick with that and the 10R tire to be safe.

I have been looking around for the wheels too. I have only located 2 of them. I hate the cost of this stuff, but what else can you do?

[JPBrecheisen]

Originally Posted by jumpsoffrock

Yes I believe they are...they are standard as to how they are advertised.

Could I trouble you for a measurement on your truck?

Looking for the distance between your inner rear dual wheel rim lip to the leaf spring pack....like in the attached photo.

I would appreciate it if its not too much trouble.

My truck has the RH-5 20x6.0 wheels and the distance on mine is about 3.5 inches on one side, and 3.75 on the other. Just want to do some quick math to make sure the extra rim width (.75) and 10R tire (probably about a .75 bulge outside the rim lip will clear my spring packs. As you can see there isn't a tone of room there. It looks about the same as yours already and my rims are supposedly only 6.0 wide.

Jonathon

[jumpsoffrock]

I hope these photos are good enough. It wasn't very easy to get any better. It looks like the problem would be in the shackles, possibly.

Let me know if I can help otherwise.
Pic 1: From spring to wheel rim
Pic 2: From spring to Tire
Pic 3: From U bolt to rim

[JPBrecheisen]

Originally Posted by jumpsoffrock

I hope these photos are good enough. It wasn't very easy to get any better. It looks like the problem would be in the shackles, possibly.

Let me know if I can help otherwise.
Pic 1: From spring to wheel rim
Pic 2: From spring to Tire
Pic 3: From U bolt to rim

The photos were perfect. Thanks for going through that trouble. Looks like should be good with the 6.75 width like you have. I plan on running a 10R tire which has a profile that is about an inch wider overall than the 235/80R22.5.

I think I'll be in good shape. When I get it all set up, I'll take pics and post.

Thanks for the help.

Jonathon

[JPBrecheisen]

Here is the semi-finished set up.

10R22.5 Goodyear G186 tread recaps and 28160J wheels from Wheels Now Inc.

The wheels/tires fit just right. I did not have the lug-hole size issue that jumpsoffrock did. Wheels bolted right up after painting and tire mounting.

[1976gmc20]

Nice truck!

I think that's about the same wheelbase as my 1965 GMC. I had a swivel log bunk mounted right over the axle, and a homemade log loader that took up about four feet of frame right behind the cab.

I also had it set up as a bobtail for a while without that loader, and could haul 12' logs comfortably - longer if not too many.

[JPBrecheisen]

Originally Posted by 1976gmc20

Nice truck!

I think that's about the same wheelbase as my 1965 GMC. I had a swivel log bunk mounted right over the axle, and a homemade log loader that took up about four feet of frame right behind the cab.

I also had it set up as a bobtail for a while without that loader, and could haul 12' logs comfortably - longer if not too many.

Thanks

You got photos of this '65 GMC you mention? Would love to see it.

[1976gmc20]

Originally Posted by JPBrecheisen

Thanks

You got photos of this '65 GMC you mention? Would love to see it.

Would have to find them and scan them - that was long before the days of digital cameras

[jumpsoffrock]

Originally Posted by 1976gmc20

Would have to find them and scan them - that was long before the days of digital cameras

Even better, love old photos.


J--Truck looks great, I am glad to hear you needed no modifications. Let's see her put to work!

[JPBrecheisen]

Originally Posted by jumpsoffrock

Even better, love old photos.


J--Truck looks great, I am glad to hear you needed no modifications. Let's see her put to work!

Agreed, old photos rule.

Thanks. Have a few other things to sort out on it mechanically, then I'll post some more when I get her working. (wood bed is a tad soft right now....)

[keith cservak]

Originally Posted by JPBrecheisen

Agreed, old photos rule.

Thanks. Have a few other things to sort out on it mechanically, then I'll post some more when I get her working. (wood bed is a tad soft right now....)

Jonathon That truck is awesome how does it go down the road with the new sneakers as good as you where hoping.
Keith.

[JPBrecheisen]

Originally Posted by keith cservak

Jonathon That truck is awesome how does it go down the road with the new sneakers as good as you where hoping.
Keith.

Thank you. I am pretty happy with it. The radials seem to make a decent amount of improvement in the ride. It didn't ride "bad" before, but the radials seem to have softened up some of the harsh bumps found on some frost-weathered northern roads. The tire guy did not do any balancing on the tires when they were mounted. He said re-caps are often difficult to balance and due to the low speed this truck typically sees, I probably wouldn't have an issue. He was right on the money. I didn't notice any tire balance related vibrations at all. The wheels seem to be a good product. The wheel/tire combo is a tad taller than the original, which is what i wanted. I wanted the taller tire to help the top end road speed a little bit. While there is an improvement, I'm sort of thinking I may need to do a gear change at some point. I'd like to be able to hit 55 without running the engine at such high RPM if I can get away with it. That will be probably next years project.

The big reason I had to switch the wheels was due to the old Firestone RH-5 split wheels. I got into this project without the knowledge of those wheels and found by talking to most experience big-truck hobbyists that they are not recommended due to safety reasons and thier history of accidents.

I like the new set up. I do think the truck seems to run/ride a little better and because they are taller, I get a few MPH out of it. The larger tires look a little nicer too in my opinion. I was hoping to get a set of the original style tubless wheels, but I couldn't find a full set. I am ok with these ones. I think they look ok now that I've had a chance to look at them for a while.

[keith cservak]

Originally Posted by JPBrecheisen

Thank you. I am pretty happy with it. The radials seem to make a decent amount of improvement in the ride. It didn't ride "bad" before, but the radials seem to have softened up some of the harsh bumps found on some frost-weathered northern roads. The tire guy did not do any balancing on the tires when they were mounted. He said re-caps are often difficult to balance and due to the low speed this truck typically sees, I probably wouldn't have an issue. He was right on the money. I didn't notice any tire balance related vibrations at all. The wheels seem to be a good product. The wheel/tire combo is a tad taller than the original, which is what i wanted. I wanted the taller tire to help the top end road speed a little bit. While there is an improvement, I'm sort of thinking I may need to do a gear change at some point. I'd like to be able to hit 55 without running the engine at such high RPM if I can get away with it. That will be probably next years project.

The big reason I had to switch the wheels was due to the old Firestone RH-5 split wheels. I got into this project without the knowledge of those wheels and found by talking to most experience big-truck hobbyists that they are not recommended due to safety reasons and thier history of accidents.

I like the new set up. I do think the truck seems to run/ride a little better and because they are taller, I get a few MPH out of it. The larger tires look a little nicer too in my opinion. I was hoping to get a set of the original style tubless wheels, but I couldn't find a full set. I am ok with these ones. I think they look ok now that I've had a chance to look at them for a while.

I'm looking to do the same thing to my 51 chevy 6400 still doing the research for the wheels not sure if the one's you used will work on truck but I want a little taller and radials hopefully over the winter I will keep driving it every day as is for now.
Keith.

[JPBrecheisen]

Originally Posted by keith cservak

I'm looking to do the same thing to my 51 chevy 6400 still doing the research for the wheels not sure if the one's you used will work on truck but I want a little taller and radials hopefully over the winter I will keep driving it every day as is for now.
Keith.

You can give the guys at Wheels Now a call. If you have your wheel measurements (bolt pattern, widths etc, I'm sure they can let you know what they have.

I think the radials are a good improvment if you're going to run it more often than not.

[factorystock]

Originally Posted by MjrBummer

I was hoping to find a good donor vehicle I can use the axles, wheel, and tires from.

Yeah it's an old thread, but common problem with c50's. Not mine, here is the ideal donor. Has all 6 ( 5-10 pattern ) 22.5" solid wheels.https://sfbay.craigslist.org/nby/cto/6125852123.html