tire size converter is online

[haven]

Here's a link to a tire size converter, courtesy of
Rockcrawler.com

http://www.rockcrawler.com/techreports/tire_calculator/index.asp

Just enter the metric tire size (e.g., 275/70R16)
and get the dimensions in inches (e.g., Outer Diameter: 31.15 "
Section Width: 10.82 " Rim Size: 16 ")

These are "standard" dimensions for the given metric size. The
actual dimensions of the tire you're planning to use will vary
from this a little for each manufacturer. But this is a close approximation.

 

[paulj]

If you aren't online it is easy to do with any calculator

275/70R16
275mm/25.4mm/inch = 10.82 inch
10.82 inch * 70/100 *2 + 16 inch = 31.15 inch
The spec tables for the tire model also give the numbers.

Here's another slick converter
http://www.eunos.com/tirecalc/
though I prefer an earlier version that allowed you to enter things like offset and gear ratios as well.

paulj

 

[HenryJ]

Here's ours courtesy of S-10CREWCAB.COM - Calculators

There is a Horsepower calculator and an Axle Ratio/Tire Size Calculator

 

[DaktariEd]

OK, so here's an odd question for you....
You can make the calculations online (a computer does the work) and with a calculator...but can you do it with a slide rule???
Does anyone out there still use one?
Is there anyone out there who has never seen/heard of one?

:sombrero:

 

[paulj]

I have slide rule, but rarely use it.
Let's, see -
put the cross hair on 2.75 on the D scale
line up 2.54 on the C scale with that
read 1.08+ off the D scale under the C's 1 - mentally adjust that to 10.8
move the cross hair over 1.4 (mentally do .7x2) on C, read 1.52 off of D
Mentally adjust decimal to 15.2, and add that to 16

The slide rule provides the details, down to a couple of significant figures, but you need to have a clear sense of the order of magnitude of your answers, and accurately juggle the decimal points.

My dad used to tell a joke about the engineer who misplaced the decimal point - his bridge fell down.

paulj

 

[DaktariEd]

Dang, you're good!
Not sure I could still do that w/o a lot of mental anguish.
And that bridge joke...wonder if that's what happened to the Tacoma Narrows Bridge...remember that?
Tacoma Narrows bridge collapse video

Oops...sorry about hijacking the thread...I'll sign off now...

 

[paulj]

The Narrows bridge collapsed, or rather the deck broke up, because the engineers neglected the effect of wind on the deck. The wind caused the deck to oscillate to the point that it flew apart.

The bridge on the Alaska Highway that crosses the Laird River uses some parts salvaged from that original Narrows bridge.

On a recent trip to British Columbia we walked across an old suspension bridge across the Fraiser River at Lillooet. Besides the usual vertical suspension cables, that bridge had some lateral stabilization cables. These cables pulled down and out at about 45deg angles on each side, stabilizing it in winds that can blow strongly down the canyon.

Under the bridge and elsewhere along the canyon, there were a number of blue tarp shelters, that are used by the local Indians (First Nations) to wind dry salmon caught during August runs. Trade in this wind dried fish helped sustain a relatively large population in the area before Westerners arrived.

paulj