metric size vs standard?

[aleej]

i think i titled that right...
so what are the metric sizes vs the standard sizes.. ie
? = 235 75 / 15
31 = ?
32 = ?
33 = ? and so on... jw

 

[Maniak]

I haven't seen a full chart.. but here is how to figure it out..

235x75 r15 tire means 235mm wide with a 75% aspect ratio on a 15" rim..

75% of 235 is 176mm
176mm converts to 6.9"... This is how much sidewall the tire has..

To get the height of the tire you double the sidewall height and add it to the rim height.. 6.9 + 6.9 + 15 = 28.8"

Sooo.. a 235x75 r15 is just under 29" tall

The width is easier.. just convert the width from mm to inches... 235mm = 9.25 (to convert it just take the mm and divide by 25.4 to get inches)


~Mark

 

[aleej]

neat thanks for that trick... so then in essence the 31" is 31 inches tall including the rim or rather 31 inches in diameter from tread to tread?

 

[Maniak]

a 31" tire is 31" tall (with our without the rim won't matter.. the rim just fills the hole in the center.. its still 31" tall)..

You only care about Rim size when your converting a metric size to a flotation size. During the conversion from metric size to flotation you are figuring out how wide the sidewall is.. To get the height you have to add both below and above the rim sidewall heights to the height of the rim to get the total height.

Keep in mind that many tires aren't exactly the size they say when dealing with flotation sizes (i.e. 31" tire is usually 30.5" or so, and some tires can be 1" off)

A tire listed in metric size is much more accurate..

~Mark

 

[jimbo74]

tehre is a calculator on www.4lo.com that lets you put in a real number and get an in iinches size

 

[Maniak]

Thats just cheating

Here the direct link to the calculator on that site.

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