Is it an illusion??????

[B-8074 19]

I changed the tires on my C-175 from 23x9.50x12's to 23x8.50x12's. Now I know they have different widths but they should be the same hight. But the new tires don't look as tall. What do ya'll think?

Before

After

[TT-(Moderator) 1,128]

It's not unusual for different brands/types of tires to actually measure more - or less than the "advertised" size. It's been that way for years.

[MikesRJ 552]

Looking at what you've bought and installed, the tire appears "smaller" due to the fact that you "stretched" a tire intended for an 8.5" with rim over a 9.5" width rim. This causes the height of the tire (from the rim to the top of the tire when inflated) to appear shorter when the tire is installed. Here's why ...

STEP 1

Look at the sidewall of your lawn tractor tire. There should be a series of numbers or numbers and letters on it. If you don't see anything, try washing the tire to make them appear. Record the numbers and proceed to step two.

STEP 2

The number sequence has either two or three sets of numbers. If a two number series go to STEP 3, if a three number series got to STEP 4.

STEP 3

In two-number sequences, the first number of the sequence is the tire width in inches (on its intended rim), and the second number will be the diameter of the rim in inches. If the sidewall of the tire reads "12.4-26", that means the width of the tire is 12.4 inches and the diameter of the rim is 26 inches.

STEP 4

For three-number series, the first number is the tire height, the second is the tire width (on its intended rim), and the third number is the rim diameter size. So for a tire that reads "16x8.0x6," the height of the tire is 16 inches, the width is 8 inches, and the rim size is 6 inches.

In your case you have two tires which are 23" tall when installed on their intended rim widths. But, when you placed a 23" tall tire intended for a 8.5" rim onto a 9.5" rim, the apparent height decreases to make up for the extra width the tire must span. Even if a tire's apparent height (from rim to top of tire) changes by just a 1/2", then the tire's overall height will be 1" shorter overall when installed on the incorrect width rim. Conversely, putting an 9.5" width tire on a 8.5" width rim will make the tire appear taller when installed.

Measure the overall height of the new tires. I'll bet they are less than the quoted 23" height they say on the sidewall. I'm sure this makes things as clear as mud now! :thumbs:

[mavfreak 11]

Tire sizes are very deceiving and must people don't know how to read them

your 23 is the width of tire

your 8.5 or 9.5 is the height of the side wall (aspect ratio or % of width)

and of course your 12 is the rim size

the is a math solution to figure out the exact height of your tires but at this hour in the morning with only one cup of coffee your not going to get that from me.

The short and long of it is the smaller the middle number the shorter the sidewall ar the it could be stated the smaller the diameter

* 23/8.5 12 is smaller than a

23/9.5 12

hope this helps

23*8.5=195.5

195.5*.04=7.82

7.82+7.82+12=27.64" this should be the height of the 23/8.5 12

now do the same thing but plug in the numbers for the 23/9.5 12 and that answer comes out to be 29.48"

confused yet cause i am :thumbs:

[buckrancher 2,675]

your 8.5 or 9.5 is the height of the side wall (aspect ratio or % of width)

no that is how wide the tire is not the height of the side wall

[mavfreak 11]

I may be wrong on this not sure

This is what I know for car and light truck tires

now that I look at the numbers I came up with there a little tall

everyone hold off on what i posted untill I figure out if car tire and tractor tire math is the same :thumbs:

[mavfreak 11]

learned something today

I was wrong the height is what it is 23 and the width is what it is 8.5 and the rim is what it is 12

why can't the car gods make it that simple.

Anyway what mikesrj said

"stand back and watch and listen, you just might learn something"

[MikesRJ 552]

I may be wrong on this not sure

This is what I know for car and light truck tires

now that I look at the numbers I came up with there a little tall

everyone hold off on what i posted untill I figure out if car tire and tractor tire math is the same

Hey Mav,

What part of these two statements did you not figure out?

STEP 3

In two-number sequences, the first number of the sequence is the tire width in inches (on its intended rim), and the second number will be the diameter of the rim in inches. If the sidewall of the tire reads "12.4-26", that means the width of the tire is 12.4 inches and the diameter of the rim is 26 inches.

STEP 4

For three-number series, the first number is the tire height, the second is the tire width (on its intended rim), and the third number is the rim diameter size. So for a tire that reads "16x8.0x6," the height of the tire is 16 inches, the width is 8 inches, and the rim size is 6 inches.

[mavfreak 11]

I never read your posts

I did but just didn't register.

but yes I was wrong And sorry I got this post all messed up with my babbling... :)

[MikesRJ 552]

You were absolutely right for car tires though. :thumbs:

[mavfreak 11]

I know :thumbs:

[KC9KAS 4,741]

At least you admit it when you are wrong!

[mavfreak 11]

I'm just here to confuse the hell out of everyone even myself :thumbs:

[rmaynard 14,907]

A standard Wheel Horse rear rim has a diameter of 12" and a width of 7" measured at the bead. The standard equipment tire was a 23 x 8.5 x 12. The tractor height specification was based on those facts. Once you put a 9.5 width tire on that 7" rim, you are going to lower the height slightly since the side walls are going to balloon out.

Your original observation of an "illusion" is slightly correct in that the tread pattern can also cause the tire to appear shorter or taller. Also, the amount of air pressure will change the equation too.

Bob

[boovuc 1,090]

Gee B-8074!

I see what your seeing from the pictures. That's terrible. I can be in Kittaning in a real short time to take that C-175 off your hands!

BooVuc

Mill Hall, PA

[mavfreak 11]

:thumbs: ok well I need to go back to school just to learn about tractor tires

[TT-(Moderator) 1,128]

I am currently dealing with tires from three different manufacturers (Carlisle, Titan, and Innova) who offer the same numerical size tire, (22.5-10X8) yet all three tires are different in height, width, and "profile" when used on the exact same rim.

Two of the three will work in my particular application, but the third tire rubs against the tie rod end.

I've also seen the same thing with 235/75-15 truck tires. A Firestone might be narrower than Goodrich, but wider than a Michelin.

'Splain that. :thumbs:

[mavfreak 11]

alot of that has to do with were the manufacture takes the measurements.

Some manufactures take it from were the tread starts at the sidewall and others take it from the inside of the first tread. And alot has to do with tread type and pattern and depth. that's why its really not a good idea to mix and match tires

I know this to be true of car tires but here again I'm on the learnin cruve for the tractor tires here

[Trouty56 565]

Once you put a 9.5 width tire on that 7" rim, you are going to lower the height slightly since the side walls are going to balloon out.

To me it would seem quite the opposite. Yes they would balloon some on the side but the tread would balloon out too giving a higher profile.

[mavfreak 11]

Once you put a 9.5 width tire on that 7" rim, you are going to lower the height slightly since the side walls are going to balloon out.

To me it would seem quite the opposite. Yes they would balloon some on the side but the tread would balloon out too giving a higher profile.

i thought same thing but i fgured to be wrong in my thinking

[Don1977 604]

I have 10.50s turfs on 7" rims and run 12 psi to keep them from balloon out the tread too much.

[B-8074 19]

Holly cow!!! You guys are making my brain hurt. MikesRj, believe it or not I was able to follow what you said . Mavfreak, Thanks for making me forget what MikesRj said. Boovuc you're welcome to come by and talk horses but you can't have the C-175 Well I was out cleaningup the leaves, AGAIN and before I started I checked the tires. Turns out that I didn't put any air in the back tires after I loaded them with washer fluid. So here is a pic after I aired them up. And I also replace the fender/seat pan with a metal one.

[stevasaurus 22,231]

I was wrong once... :thumbs:

[B-8074 19]

I'm wrong all the time. Just ask my wife. :thumbs:

[mavfreak 11]

I'm wrong all the time. Just ask my wife.

my wife tells me that so much that I believe her. And thats why I always admit to being wrong even when Im not wrong which I could be wrong now....Let me go ask her.

if you ever need to be confused and a headache again just let me chime in.

air helps alot doesn't it.

How well does the washer fluid work for you? Does it eat the wheels any? Is it heavier than antifreeze?

And by the way she says I'm wrong :)