Rim Size and Tire Size Limits

[55 Fargo]

Hey all, made the step towards switching back to OEM steel rims and I have just acquired 4 "Fargo" hubcaps.

I have 2- 5 X 15 rims and 3- 4 1/2 X 15 rims.

Now I need at fairly good sized tires, right now I am running P 235 75 15s, most you Pilothouse owners no doubt run 16s, and better choice in taller skinnier tires for that wheel size too.

What can work on these small rims widths with today's modern tires.

I cannot use P 205 75 15s, they would look ridiculous on my truck....

[Merle Coggins]

I'm running 235/75R-15s on my 15x5" rims. 

[55 Fargo]

16 minutes ago, Merle Coggins said:

I'm running 235/75R-15s on my 15x5" rims. 

Thanx Merle, they will go on and be okay on 5s, today threw on an old P215 75 15 on a 4 1/2 wide rim, no problems.

Could I get away with P 235 75 15s on a  4 1/2 rim, probably but will they look buldgy....

Trouble is anything smaller than a P 235 75 15 does not look right on these trucks...

[55 Fargo]

So looks like Merle is the only member who has installed bigger modern radials on either 4 1/2 or 5 inch wide rims? The older trucks are 16s with most what at P 215 85 16, but what are you guys running on stock rims with 15 inch radials? Cokers and repop bias plys are out there, but don't want em and the are pricey...

[Reg Evans]

I'm running stock 15" rims on my 52 1/2 ton.  They are Federal brand M+S size 30 x 9.5 R15 LT

[55 Fargo]

Nice tires Reg, those 5 inch wide rims or 4 1/2 inch wide rims?

They sit on the rims well....

I really think I may not have too many issues with P235 75 15 tires on 4 /12 inch rims but have not tried it yet.

I have 2- 5 inch wide rims and 3- 4 1/2 in ch wide rims, so far....

[Reg Evans]

I'm not sure if they are 4.5 or 5.   The rims do have the hub cap clips if that tells you anything. Sorry

[55 Fargo]

1 hour ago, Reg Evans said:

I'm not sure if they are 4.5 or 5.   The rims do have the hub cap clips if that tells you anything. Sorry

Thanx Reg, will be either or, but your tires look great on there...

[fargo52]

These are 235/65. 16" on 5" wide rims . 

[fargo52]

How do I send more than one picture ??? I keep getting "3mb picture only warning "

[55 Fargo]

9 hours ago, fargo52 said:

How do I send more than one picture ??? I keep getting "3mb picture only warning "

You may have to reduce your picture resolution size to upload multiple pictures.

Next open your pic files, hit control and click on say 3 pics, and hit open they will upload if not too big...

A pic of a test look with a stock 15 inch rim, Fargo cap, and P215 75 15 tire, which is way too short.

This is a 5 inch wide rim...

 

[55 Fargo]

installed a P 235 75 15 tire on a 5 inch wide rim, I like the look.

I did a test fit, this rim will now be blasted and painted "guess what color" hang on it will be red rims, whew hoo.

[st63]

From experience, I can tell you that running a 215 or wider radial on 4 1/2 or 5" wide stock rims is asking for trouble. The tire manufacturers list a minimum rim width of 5 1/2" to 6" for those.  Jamming them onto narrower wheels leads to excessive sidewall wear.  For a 5" wide rim, you can use the Yokohama RY 7R15 LT radial...it's taller than the 215, 225 or even 235 series tires by more than an inch,  and looks a lot like the O.E. bias style tire. Gives you a stock look with modern performance. Also a lot easier on original steering components, as it's not excessively wide.  I've used them on my old trucks for some time now with great results.   If you want to run a heavier tread tire on the back, old school style, they make Y742S in the same size.  No, I don't work for Yokohama...just like the tires!

http://www.tirerack.com/tires/tires.jsp?tireMake=Yokohama&tireModel=RY215&partnum=700R5215&vehicleSearch=false&fromCompare1=yes  

Edited February 3, 2017 by st63

[55 Fargo]

29 minutes ago, st63 said:

From experience, I can tell you that running a 215 or wider radial on 4 1/2 or 5" wide stock rims is asking for trouble. The tire manufacturers list a minimum rim width of 5 1/2" to 6" for those.  Jamming them onto narrower wheels leads to excessive sidewall wear.  For a 5" wide rim, you can use the Yokohama RY 7R15 LT radial...it's taller than the 215, 225 or even 235 series tires by more than an inch,  and looks a lot like the O.E. bias style tire. Gives you a stock look with modern performance. Also a lot easier on original steering components, as it's not excessively wide.  I've used them on my old trucks for some time now with great results.   If you want to run a heavier tread tire on the back, old school style, they make Y742S in the same size.  No, I don't work for Yokohama...just like the tires!

http://www.tirerack.com/tires/tires.jsp?tireMake=Yokohama&tireModel=RY215&partnum=700R5215&vehicleSearch=false&fromCompare1=yes  

yes yokohama is a good tire and I like it too, but not what I am looking for. Tire manufacturers spec this trie at a 5.5 inch to 7 inch rim, so 1/2 inch is not a deal breaker.

The big problem according to a very knowledgeable tire dealer I got acquainted with says, its the the issues with wear on the center of the tire thats why the manufacturer does have a standard, for warranty and liability issues.

By chance what credibility do you make this statement, as I can also read info on the web say from Tire Rack?

I do not ask this looking to argue, but do you have some history or experience on this.

BTW, the Yokoham RY 7.10 15 is a taller tire, heavier sidewalls, and a section with about a 1/2 inch narrower than a standard P 235 75 15, not a whole lot. This tire is also close to an inch taller, it is speed rated to 65 mph, not what I am looking for exactly, but a nice tire.

Many Many folks run this tire on 5 inch wide rims and even narrower without problems, did you have any that you can share with us, as I am all ears....thanks 

FWIW, when I personally mounted this tire on a 5 inch wide rim, it went on super easy and set beads nicely, I have 6.5 inch rims with this same tire, and the only difference is a slight sidewall bulge, and I did the look

Edited February 3, 2017 by Rockwood

[Los_Control]

10 minutes ago, st63 said:

Yokohama RY 7R15 LT radial...it's taller than the 215, 225 or even 235 series tires by more than an inch,

the  correct way to read tire sizes 235- 75-R-15

235 is the height of the tire

75 is the width of the tire

R is indicating a radial, B would be a bias

15 is the rim size.

Is kinda stupid but funny how the tire width is / was explained to me. 75 means it is 75% wide as it is tall.

I did not create the system, I dont claim to agree with it, but it is what it is.

A 70 series tire is wider then a 75, a 60 series is wider then 70 and the 50 series are ...

A quick glance at a random online tire store, they do make some 80 series tires, but did not see them in the height you would want.

A 235-75-R-15 would be ideal height and width for the trucks, the tire says a 6" rim is recommended.

Putting the tire on a skinnier rim, would poof out the sidewalls and create a arch at the tread area, not nice and flat like you want.

I do not think that a 75 series tire and a 5" wide rim you will notice. A 70 series you might be able to see it, a 60 series and oooh boy we got a problem.

But a 75 series I think you will be just fine.

Ideal rim width, maybe not. But look at your options and go with the lesser evil.

[59bisquik]

4 hours ago, Los_Control said:

the  correct way to read tire sizes 235- 75-R-15

235 is the height of the tire

75 is the width of the tire

Looks like you got a little mixed up. 235 is the width of the tire and 75 is the height of the tire.

[Los_Control]

Just now, 59bisquik said:

Looks like you got a little mixed up. 235 is the width of the tire and 75 is the height of the tire.

In a past life before I became a carpenter, as a kid I started out running a service truck repairing semi truck tires, did that for a few years and then I started off in a shop retreading truck tires. I retreaded for about 14 years. During that time I spent much time in school for repairing tires, I was a certified Bandag master craftsman for over ten years and eventually ended up managing the retread shop. When that shop sold, I went to another company and started a off road tire repair shop.

In my late 30's was tired of breathing rubber dust and I wanted a change, moved on to carpentry.

Just saying, I have been around a tire or two, the 235 is the height and the 75 is the width.

[59bisquik]

I have never built or retreaded a tire and do not wish to argue... but you are incorrect. Look at the link to Goodyears website.

http://www.goodyearautoservice.com/content/content.jsp?pageName=TireSize

[55 Fargo]

Gentlemen, is the tire upright or laying down?

Tire Width is the width of the tire measured in millimeters from sidewall to sidewall. The first three-digit number in the tire sizerefers to the tire width. For instance, in a size P215/65 R15 tire, the width is 215 millimeters. Aspect Ratio is the ratio of the height of thetire's cross-section to its width.

[Los_Control]

4 hours ago, Los_Control said:

Is kinda stupid but funny how the tire width is / was explained to me. 75 means it is 75% wide as it is tall.

I did not create the system, I dont claim to agree with it, but it is what it is.

I agree, arguing on the internet is about as productive as counting ants in your garden.

Back in the day before metric radials, we had L R 78 15 The L would be the height again and the 78 the width.

When we got the metric radials, the same concept was carried over and used for years. I see all are calling the 235 the width and the 75 the aspect ratio.

Honestly this is a sales tool imho, makes it sound like rocket science and you are getting the latest space age technology with our tires.

If we are so precise with the measuring, why does two different brand of tires with the same size stamped on it, differ in height and width when you stand them next to each other?

If you go to tire rack and look at a tire size in inches, say a 235 75 15 is 30 " tall, then you change the 235 to a 225, what changes is the height of the tire in inches.

To me this is the common sense way of telling the tire size. Ask any 4x4 off roader, they want to go to 33 inch tall tires on their truck, they need to get 265 75 tires.

What changed between a 235 tire at 30 inches and a 33 inch tire is the first 3 numbers.

The tire manufacturers can call it the width if they want, it determines the height and according to the tire manufacturer, there is no hight reference, only width and aspect ratio.

Oh wait ... that is the height. When I want to know how tall a tire is, I will look at the first 3 numbers and the next 2 numbers will tell me the width.

 

[55 Fargo]

10 minutes ago, Los_Control said:

I agree, arguing on the internet is about as productive as counting ants in your garden.

Back in the day before metric radials, we had L R 78 15 The L would be the height again and the 78 the width.

When we got the metric radials, the same concept was carried over and used for years. I see all are calling the 235 the width and the 75 the aspect ratio.

Honestly this is a sales tool imho, makes it sound like rocket science and you are getting the latest space age technology with our tires.

If we are so precise with the measuring, why does two different brand of tires with the same size stamped on it, differ in height and width when you stand them next to each other?

If you go to tire rack and look at a tire size in inches, say a 235 75 15 is 30 " tall, then you change the 235 to a 225, what changes is the height of the tire in inches.

To me this is the common sense way of telling the tire size. Ask any 4x4 off roader, they want to go to 33 inch tall tires on their truck, they need to get 265 75 tires.

What changed between a 235 tire at 30 inches and a 33 inch tire is the first 3 numbers.

The tire manufacturers can call it the width if they want, it determines the height and according to the tire manufacturer, there is no hight reference, only width and aspect ratio.

Oh wait ... that is the height. When I want to know how tall a tire is, I will look at the first 3 numbers and the next 2 numbers will tell me the width.

 

Thanks for the explanation, Los Control, BTW your opinion on the P 235 75 15s on a 5 inch wide rim or even a 4 /12 inch wide rim.

What is the pitfalls in doing this?

[Los_Control]

What happens is you get a crown in the tread area, you will be riding on the center of the tread and not full contact with the road.

This will lead to irregular and premature tread wear, a bit of a safety issue with possible hydro planing on wet surface. And generally bad handling while driving.

 

This would be extreme conditions. With the 5" wheel, I do not think you will see any of these conditions. And if you do, you could maybe adjust it out running 30 pounds air instead of 35 to get the tread flat. You would not be under inflated and get a good ride and handling.

The 4.5" wheel really is getting to narrow for modern radial tires.  I think the 5" wheels will be fine, 4.5 I would avoid.

 

What I am going to do, replace my old original wheels with modern steel 6" wheels.

I have 2 trucks, a utility trailer with a old dodge axle, and a 51 plymouth car will be parting out, I have 15 original dodge wheels with locating pin holes. Probably more if I look around. I dont trust any of the old wheels for a daily driver.

For the new wheels I end up with, I want a small dog dish hub cap on them, and will make a simple jig out of plywood to mark the locating pin holes and just drill them out by hand, keeping the old drums.

Just saying what I will do, but I think you can get by with 5" wheels.

 

I will add, while pulling my truck around the yard in soft dirt on a chain, had to try and pull the front sideways just a bit to point it into a parking space.

This cracked the wheel around the bolt holes, pretty bad actually.

This could have happened driving and need to make a panic stop and sharp turn to avoid a collision, or just parking and bumping a curb.

Just to many years on these old wheels to put up with daily driving conditions for me.

Edited February 4, 2017 by Los_Control

[lonejacklarry]

9 hours ago, Los_Control said:

 I will add, while pulling my truck around the yard in soft dirt on a chain, had to try and pull the front sideways just a bit to point it into a parking space.

This cracked the wheel around the bolt holes, pretty bad actually. 

I had not even considered that might be a problem.  Thanks very much!  One less decision to make now.

[st63]

I don't take offense or view it as arguing at all...I'm only giving my opinion (for what it's worth) on the Yokohama tires based on my experience on actually using them on vintage trucks that I own or have owned in the past.  Maybe you missed the part where I said that I've used these tires on my own trucks.   I also explained the pitfalls of using too wide a tire on too narrow a rim, something I also learned from experience. (I had a '65 Chevy C10 where a previous owner had installed 235 series radials on the original narrow rims, and the truck was excessively hard to steer. The sidewalls also developed cracks from being mashed into a rim narrower than they were designed for. I know other people who've run similar size tires and consider them "fine" too, but it's going to lead to premature tire wear and stress on the rims if any serious miles are put on them)  I did the research on what tires would best fit my original rims and would be closest in size to O.E., and made my decision from there.   I've been happy with them, and that's what I base my opinion on. Besides the 65 C10,  I've also used them on everything from a 52 Dodge to a 53 IH, 67 Chevy and 68 IH.  None were "show trucks", but trucks that I used daily for work and put a lot of miles on.  You asked what tire would work on those old narrow rims and that's just my 2 cents, nothing more. 

Edited February 4, 2017 by st63

[greg g]

I have 15 inch aftermarket steel rims on my P15, they are 5 inches wide. I run 205 75 fronts, and 225 75 rears.  With just under 40k miles on the fronts which I run at 34 psi, I have no unusual wear and probably another 10 to 15k treadwear left till replacement will be needed.  The rears run at 32 psi have about 25k on them have 9/32 of tread left and show normal tread wear.  Both tires recommended a 6 in minimum wheel width, but seem to be functioning just fine on the 5 inch wide wheel.  My car is a business coupe, and with tool box, bottle jack, and box of spare parts, and another box of necessary items there is probably around 65-80 pounds of stuff in the trunk as a constant.

I average about 3500 to 4000 miles per season added to the odo.