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Discussion Starter · #1 ·
Hi, Shiggy. This is something I've wondered about for a while. I like the biggest balloniest tires I can find, and mtbtires is my go-to source for this info.

My best guess would depend on whether you determine volume using the inside surface or the outside surface of the tire. If it's the outside, simple displacement of water in a tank would work. If the inside, I'd guess you inflate it with water and measure the amount it takes to attain a standard pressure. If neither, then you must have aced calculus.

So, would it be revealing a trade secret to tell us how you define it and how you measure it?

Thanks, and thanks for mtbtires.
 

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Gasp4Air said:
Hi, Shiggy. This is something I've wondered about for a while. I like the biggest balloniest tires I can find, and mtbtires is my go-to source for this info.

My best guess would depend on whether you determine volume using the inside surface or the outside surface of the tire. If it's the outside, simple displacement of water in a tank would work. If the inside, I'd guess you inflate it with water and measure the amount it takes to attain a standard pressure. If neither, then you must have aced calculus.

So, would it be revealing a trade secret to tell us how you define it and how you measure it?

Thanks, and thanks for mtbtires.
Technically the volume index is a cross section area measurement.

http://mtbtires.com/site2/tech/34-how-we-measure-/46-how-we-measure-the-tires

Glad to be of service. I enjoy doing it.
 

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Discussion Starter · #3 ·
I suppose I could have looked a little harder to find that! Thanks.

Volume Index:
A relative number to compare air volume. Calculated by multiplying casing width by casing height (in mm) and moving the decimal point two places to the left. Because this is an outside measurement it is affected by thick casings and tread base rubber (i.e. if two tires have an index of 25.0 the actual volume of the tire with the thicker casing/base rubber is lower than the thinner casing/rubber tire). This is the third version of the index.
 

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Hey
shiggy you sight won't let me see it :( it says "404 forbiden"
 

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ae111black said:
Hey
shiggy you sight won't let me see it :( it says "404 forbiden"
My web provider is upgrading servers. Should be back up soon. They claimed no more than a 30 minute disruption very early this morning. :bluefrown:
 

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shiggy said:
My web provider is upgrading servers. Should be back up soon. They claimed no more than a 30 minute disruption very early this morning. :bluefrown:
OK!
 
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