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Discussion Starter · #1 ·
OK, I give up! What tape measure do they use to measure tires? :dunno:

I ordered these 18x7.50x8 tires to use on either a Gravely 2 wheel tractor or a Cub Cadet Super GT.

Tire Automotive tire Wheel Product Automotive wheel system


The tires are as tall as a 18x8.50x8, but, the IDENTICAL width as a 16x6.50x8.

I thought the middle number is the tread width!!??:dunno:

The new tires are Carlisle Turf Savers and I only compared them to Carlisle Turf Savers.

All one brand, I would think one manufacturer would keep the numbers in order.

Anyone else baffled by tire sizing??
 

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Discussion Starter · #3 ·
What is the width of the rim to which you mounted them?


I put them on the Cub Cadet rims, identical width as the ones shown in the picture.

The 7.50 and 6.50 even have the identical tread pattern, 4 bars across.

Bar size and spacing are identical!! It is like they used the same tread in both molds. :dunno:
 

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I thought the 8.5/ 6.5 /10.5 and so on, measured the bead with so you wouldn't put a 10.5 on a 6" rim. Not necessarily the tread width?
 

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I thought the 8.5/ 6.5 /10.5 and so on, measured the bead with so you wouldn't put a 10.5 on a 6" rim. Not necessarily the tread width?
Actually, it is the maximum sidewall width, from the widest part of the outside of the sidewall to the widest part of the inside of the sidewall on the opposing side (when mounted to a specifically sized rim). AKA cross-sectional width. Tread width does not enter into the equation.

The rim width is the width at the bead seating section of the wheel. It is typically 1.5" to 2" less than the cross-sectional width of the tire to ensure a good seal.
 

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Actually, it is the maximum sidewall width, from the widest part of the outside of the sidewall to the widest part of the inside of the sidewall on the opposing side (when mounted to a specifically sized rim). AKA cross-sectional width. Tread width does not enter into the equation.

The rim width is the width at the bead seating section of the wheel. It is typically 1.5" to 2" less than the cross-sectional width of the tire to ensure a good seal.
I can see that now. Thanks, anyways it doesn't mean that the tread width would be wider just the sidewalls. Depending on how wide the sidewalls are could mean the tread is wider on the really wider tires, like a 12 width.
 

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I'm not looking to highjack the thread but while reading it I thought of asking. I had a worn out set of tires mounted 225/70R15 and a near new set of 205/70R15 unmounted. So I mounted the "new" set of tires but the rims are wide, tough time to get the beads to seal, and now I'm thinking maybe it could a safety issue involved. Any thoughts? I'm going to be breaking one to replace a valve stem that is leaking from the base. I can get a measurement then.
 

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Discussion Starter · #11 ·
I'm not looking to highjack the thread but while reading it I thought of asking. I had a worn out set of tires mounted 225/70R15 and a near new set of 205/70R15 unmounted. So I mounted the "new" set of tires but the rims are wide, tough time to get the beads to seal, and now I'm thinking maybe it could a safety issue involved. Any thoughts? I'm going to be breaking one to replace a valve stem that is leaking from the base. I can get a measurement then.

That is the same concern I have with the 18x7.50x8's.

Since the "aspect" is 1" wider than the old tires, and the tread is the same, more sidewall is exposed to damage. :crybaby:

If I was running car tires, I would not worry, unless you drive into curbs a lot!! :dunno:

I have noticed the "Narrow Tread" phenomena on low cost car tires. They sell you aspect width, and cheapen the tire with narrow tread.

Where is the Feds when you need them!! :praying:
 

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OK, I give up! What tape measure do they use to measure tires? :dunno:
...
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Anyone else baffled by tire sizing??
Yes, I am baffled to. The 24x12-12 carlisle turfs on my x500 measure 22.3" diameter when inflated to 10psi. Yet Carlisle specs for the 23x10.5-12 are 1" larger at 23.3" mtd diameter. So if I want bigger tires I need to step down a size? Go figure!
 
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