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volcom426

Rims To Small For Tires?

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Hi Everyone,

I just purchased my first class A motor home.  I have been going through everything on it and realized that the prior owner has put 295/75  (22.5) tires on the coach. They are a year old Toyo M177. The coach originally came with 275/80 front and 275/70 rears. So I though to myself no biggie they are about an inch bigger and wider, who cares.  So the coach came with accuride rims which need some polishing  (i have the attention span of a gnat and polishing drives me insane).  I have a background in trucking  and have seen Alcoa make leaps in bounds in coating technologies for there wheels.  I thought maybe i should just get a new set of wheels and never worry about having to polish them for a while. So I started looking what a set of new Alcoa's would cost.  This is when I found an issue. The rims on the coach are 22.5x7.5 stud pilot.  Alcoa doesn't make that wheels size with stud pilot? Everything they make is 22.5x8.25 SP (i could be mistaking) or bigger. So I started looking more into it and then realized that the tires on my coach are suppose to have 8.25-9.00 wide wheels.

I am now a concerned that i could possibly have a tire failure because of this. Also my polishing the old rims option just flew out the window. 

I have an extensive background in automotive/truck performance and repair but never really took much time learning tire theory.  I have plenty of clearance between the duals. The only issue that could possibly arise is side wall problems. Knowing what i have seen sidewalls go through on truck tires I think I might be overthinking it a little.  If anyone has any experience with this or knowledge and advice would be much appreciated.

 

PS:  I already thought about calling Toyo, but being a product manger myself currently anything involving safety we are trained to say NO you cant do that

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volcom426.  Welcome to the Forum!

Would be helpful to know, make, model and year of your coach.  Also GVWR, actual weight front, rear at least.  Does it have a tag?

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I don't think that accuride wheels are stud pilot (SP), all that I have ever seen are hub pilot (HP). (SP) are normally on coaches before 1990, as Bill said what make and year?

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Some tires can be mounted on rims smaller than the chart shows, but suffer a reduction in their load capacity. For example, our coach is riding on Firestone FS40 in 315 size. They normally have an L load rating with a 130psi max pressure. That assumes mounting on a 9" rim. Our rims are only 8.25" and I had the same concern as you. I dug into the Firestone Data Book and round that the tires can be mounted on the narrower rim, but that the weight limit is reduced to what's listed in the column for 120psi.

My suggestion would be to get a copy of the tire data book for your tires and dig deep into it. If you still can't find the answer, call the manufacturer and speak to someone in their technical department to see if they have information on the weight limits when mounted on your rims. You may be able to keep your current tires but at a lower weight limit.

I'd also suggest a call to the manufacturer of your coach to see if you can mount the 8.25" rims on your coach safely. That would be an easy (although not inexpensive) fix. They should be able to tell you the max tire/wheel size permitted.

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Did some checking in the 2018 Tire & Rim Standards book for both tire section and the rim section. The 295/75R22.5 size tire and the only "approved" rim widths are 8.25 and 9.0.

Toyo only shows 8.25 - 9.0 as approved rim width

I would be surprised if you find a Toyo rep that would approve the   7.50 rim width but they might have some internal company information.

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So, maybe he has a 1980's coach!  

This is not a good forum to say you are one thing and not.   I will give him the benefit of a old coach!

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13 minutes ago, manholt said:

So, maybe he has a 1980's coach!  

This is not a good forum to say you are one thing and not.   I will give him the benefit of a old coach!

volcom426,

Yes, Welcome to the FMCA Forum.

For better answers, a good idea to go in and add your coach to your signature (see others on this thread).

Yes, wheel type really depends on year/era of the coach.

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Thanks for all the replies, Thank you wolfe,  I'm looking into doing that right now.  

 

The Coach Is a 1999 American Eagle 40EVS with a spartan chassis.  It has the IFS1200 front independent suspension and it does for sure have stud pilot wheels. 

In response to manholt the,

GVWR is 31k 

Front GAWR is 12k

Rear GAWR is 19k

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1 hour ago, hermanmullins said:

I don't know the difference between STD PILOT (SP) and HUB PILOT (HP) studs. Please enlighten myself and I bet a lot others out there. I haven't learned anything new today.

Herman 

Hp use a 2piece nut and a sp wheel tapered nuts with double nuts on the rear duals.

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Herman, hub pilot actually rides on the hub, center hole of the rim is the almost exact as the hub, the stud holes are straight through instead of tapered. As Carl said stud pilot the lug nuts are tapered like the lug nuts on your car and pickup truck, and of course the lug holes are slightly larger than the stud and dependent of the lug nuts causing the wheel to center because of the taper. Alcoa wheels and labeled as such are actually Arconic brand, Accuride is just another manufacturer of wheels, they probably use Alcoa aluminum also but are not authorized to use the name. Hope you learned something new today Herman, it's hard get a new one on you. As DD69 described, the dual inside is threaded on the inside with a shoulder which holds the inner wheel in place with a larger set of male threads after the shoulder to hold the outer wheel, there is a square end on the inner nut that requires a square nut driver to tighten that nut, then a 1.5 tapered hex nut to hold the outer wheel in place, these are commonly called Bud wheels. I have the socket for installing this type, the inner of the socket contains the square driver, and the outside is the 1.5 hex socket.

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Now I know. Thanks. This is why when I have a tire issue I go to a shop. Then I stand back and watch incase I am every am in a situation where I must do it myself.  Which I pray I never have to do it.

Again thanks to all.

Herman

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Here's what the lug nuts look like for a stud pilot rear wheel with dual wheels. The long part (Budd nut) holds the inner to the studs. The nut then is used to hold the outer to the threads exposed on the inner Budd nut. A square socket is used to tighten the Budd nut, and a standard lug wrench for the outer.

Lugnuttool2.jpg

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5 hours ago, richard5933 said:

Looks like an Alcoa 22.5 x 8.25 stud pilot on this page (towards the bottom)

https://buytruckwheels.com/collections/twenty-two-half-eight-quarter

Is this what you are looking for?

Thanks Kay,

Yeah those are it but not in the dura-brite version.  I might have to settle if nobody can get the Dura-Bright version.  See below

88311 - Ball Seat 22.5" x 8.25" on 11.250" bolt circle

FINISH PART NUMBER
Dura-Bright®
Polished Both Sides
883113DB
Clean Buff Both Sides as applicable³ 883117
 
SPECIFICATIONS MEASUREMENT
Size 22.5 x 8.25
Bolt Circle 11.25
Hub Bore Diameter 8.722
Bolt Hole Diameter 1.18
Max. Wheel Load1 7200
Wheel Weight 52
Outset2 6.66
Inset 5.68
Max. Inflation – cold 130
Valve Stem TR555D
Stabilizer 2225
5 hours ago, manholt said:

22.5 x 7.5 !  Good luck with that.  I also wonder what the DOT# is on his current tires?

Dot is 1617, the tire have maybe 3k on them.

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So I have some updates.

 

I talked to my sales rep for my forklift tire supplier, which they also do heavy duty truck tires and road service.  Reputable company here in southern California. told him the story and he said your fine run them.  

Called Toyo (this is a little amusing) talked to a lady from the tech department and told her the story she said "  Oh.  well that will void the warranty and you will get a little abnormal tire wear". Told her the tires are on a motorhome and advised her the tires would probably rot before I ever ran into tire wear issue.  This is where it gets good.

She says "hold on a second", puts me on hold for about 2-3 minutes.  First thing she says when she picks up the line "nope, tires will fall off". So i chuckled and told her "we went from abnormal tire wear to wheels falling off since i was on hold"?  So in a nutshell Toyo says No, my tire guy says your fine.

The prior owner of the coach is a pretty nice guy and advised me to call him with any questions.

 Im debating whether i should call him and get the tire shop he used and have them replace the tires.  I'm pretty sure when i bring this up to the tire shop that Toyo Says "Nope, the tires will fall off"  they will most likely be accommodating.  Im pretty sure i know who replaced the tires if my memory serves me right but want to make sure if i cause a stink.

Or i just get the rims Kay showed me and have them swapped over and call it a day. 

So i guess the moral of the story is don't always trust what shops recommend and research it and tell them what to put on. 

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12 hours ago, wolfe10 said:

volcom426,

Yes, Welcome to the FMCA Forum.

For better answers, a good idea to go in and add your coach to your signature (see others on this thread).

Yes, wheel type really depends on year/era of the coach.

Wolfe, i finally figured out the signatures.  There is an option for showing signatures in the settings that's not on until you turn it on.  Thanks again.

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Volcom, any reason you are not going to run the stock tire on the coach? Wider tires on narrow rims present a hazard and will often cause the tire to crown in the center. I may have gotten lost somewhere in all of these posts, sorry if i'm mistaking. If you are changing the wheels then id say go for it, the Dura-Bright wheels we have at work are fantastic! Just make sure you get the correct offset to allow for steering and dual wheel clearance so the duels do not "kiss" while traveling. 

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3 hours ago, jleamont said:

Volcom, any reason you are not going to run the stock tire on the coach? Wider tires on narrow rims present a hazard and will often cause the tire to crown in the center. I may have gotten lost somewhere in all of these posts, sorry if i'm mistaking. If you are changing the wheels then id say go for it, the Dura-Bright wheels we have at work are fantastic! Just make sure you get the correct offset to allow for steering and dual wheel clearance so the duels do not "kiss" while traveling. 

Good Morning, I recently bought the coach and the prior owner put these incorrect new tires on.

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6 minutes ago, volcom426 said:

Good Morning, I recently bought the coach and the prior owner put these incorrect new tires on.

We went through the same with our coach 5 years ago. Ours were the incorrect size and load range that were installed by the RV dealer, talk about NO attention to detail that could have resulted in an accident.

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