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Discussion Starter #1
Last night I finally got around to making some outside diameter measurements. Hope they help.

All these tires are mounted on an oe rim. All were measured in the middle of the tread.

Pirelli Eufori 195-55-16 at 35 lbs & 2k miles....................75 1/4 inches

Brand new Metz ME880...180-60-16 at 41 lbs..................75 1/4 inches

Metz ME 880..180-6-16 with 3/32nds tread at 41 lbs........74 1/8 inches


Now if I could just find a spare front wheel at a reasonable price :) Three rears should do me.
 

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trialsman said:
Brand new Metz ME880...180-60-16 at 41 lbs..................75 1/4 inches

Metz ME 880..180-6-16 with 3/32nds tread at 41 lbs........74 1/8 inches
:?: :?: :?:
Identical tire but one wore down 1.125 inches on the diameter. That is .5625 inches of tread. I am missing something here. If the last one was 75 1/8 instead of 74 1/8, I'd believe it.

So what am I missing?
 

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weengers said:
trialsman said:
Brand new Metz ME880...180-60-16 at 41 lbs..................75 1/4 inches

Metz ME 880..180-6-16 with 3/32nds tread at 41 lbs........74 1/8 inches
:?: :?: :?:
Identical tire but one wore down 1.125 inches on the diameter. That is .5625 inches of tread. I am missing something here. If the last one was 75 1/8 instead of 74 1/8, I'd believe it.

So what am I missing?
Actually, thats 1.125 inches difference in circumferance. Not the same as diameter. Sounds about right to me.

My Avon had 12/32 tread depth when new, I don't know about a metz.
 

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Discussion Starter #4
Weengers
The worn Metz was worn flat in the middle, like most tires do. That's the difference in outside diamter, if I'm reading your question right.

Galute,
The new Metz tread depth was 8/32nds or 1/4 inch. I'm measuring in the groove as close to the middle as I can get.
 

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trialsman said:
Galute,
The new Metz tread depth was 8/32nds or 1/4 inch. I'm measuring in the groove as close to the middle as I can get.
But you're measuring circumference, as galute stated, rather than diameter. A tire 75 1/4" in diameter is over 6' tall! You'd need a ladder to mount the Wing. :lol:
 

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AKLDRIDER said:
But you're measuring circumference, as galute stated, rather than diameter. A tire 75 1/4" in diameter is over 6' tall! You'd need a ladder to mount the Wing. :lol:
DUH! I should have caught that, now I see what I was missing. Thanks Galute and AKLDRIDER.
 

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Discussion Starter #7
Duh, is right............

Yes, I was calling circumfrence outside diameter. I are to stoopid :oops:

What is the difference? I thought the outside diameter was the same as the circumference.
 

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Diameter is the distance across the circle.
Radius is distance from the center of the circle to the outside. 1/2 the diameter.
Circumference is distance around the circle.
 

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Outside diameter is a machinist term to differentiate between Inside and Outside Diameter.

Inside Diameter would be the measurement of a hole.
Outside Diameter would be the measurement of a shaft, (or a tire :wink: )
 

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Hey, don't feel bad guys. I had to edit 3 times before I got it right. It was 21 degrees here when I got up. My brain was froze but I knew what Paul was trying to say. :lol:
 

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Diameter

If the inside diameter is larger than the outside diameter then the hole is on the outside
 

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Re: Diameter

Dennis Elliott said:
If the inside diameter is larger than the outside diameter then the hole is on the outside
That phenomenon is called tire prolapse and is ugly to behold.
 
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