How do you translate auto tire sizes?

[Holyman]

I'm trying to find out the widest, lowest profile tire I can get for a 14" rim and I thought a 190-40-14 would be in the neighborhood of 22" tall 10" wide 14" rim but I have no real way of figuring it out.

[DUNEDEMON]

here you go... http://www.powerdog.com/tiresize.cgi

[Master of Faster]

190/40-14 would be 190mm wide with a sidewall that is 40% the dimension of the width which would be about 76mm on a 14" wheel. I believe that's how it goes if I remember correctly.

 

First number is the tread width, second is the aspect ratio (profile) and third of course is wheel diameter.

Edited August 29, 2005 by Master of Faster

[Holyman]

I must be completely stupid but I can't figure out how to use the darn thing.

[Holyman]

So would a 260-80 give me about 22" high over all and 10" wide?

[Master of Faster]

According to that calculator a 190-40 would be 20" tall and a 260-80 would be 30" tall.

 

The 260-80 would have alot of sidewall.

Edited August 29, 2005 by Master of Faster

[Holyman]

Now that you guys tipped me off to the idea that there are tire calculators out there, I have gotten even more confused.

This site http://www.eunos.com/tirecalc/ says a 170/60-14 is 22" tall.

This site http://www.dakota-truck.net/TIRECALC/tirecalc.html says a 254/40-14 is 22" tall. It also says a 170/60-14 is 22" tall.

And this site gives me every tire in the warehouse http://ejelta.com/tiresize/index.html?tire...eel=&maxdelta=2

[RATBIKE0130]

Ok here is what you need to do. First take your tires width 190 for example. Divide 190 by 25.4 thus converting the tires width in mm to inches. You end up with a 7.48 inch wide tire. Now you take your 40 which is the percentage of the tires width to get the side wall on one side of the tire. 190 X .40 = 76mm like MOF said. Again divide that by 25.4 to get your inch dimension. 76/25.4 = 2.99 round up to 3" to make it simple on yourself. Since this dimension is only from the edge of the wheel to the edge of the tire on one side you multiply it by two. Add this number to your rim size and you will get your tires diameter. 3x2 = 6... 6+14= 20

 

Your 190-40-14 tire is 20 inches tall 7.48 inches wide and probably not what you are looking for.

 

Look for something with the largest width 265-305 and very small aspect ratio 35-40 series on like a 16-20 inch wheel.

 

Disreguard the last part about wheel size since you are looking for something on a 14" wheel... good luck

Edited August 29, 2005 by RATBIKE0130

[STLBILL]

If you are married to those specifications you need a 254/40/14. I suspect you'll want to vary it a little unless you own a tire manufacturing facility... :-)

 

254 / 25.4 = 10 inches wide (25.4 is the number of mm in an inch)

254 x .40 = 101.6 or exactly 4 inches of sidewall

14 inch wheel + 4 inch sidewall X 2 sidewalls = 22 inches tall and 10 inches wide on a 14 inch rim.

 

There is no other combination that will meet the specification you stated.

 

 

-Bill

[04ShEeLE]

Why would you ever want to run a 14 inch wheel? Step up and buy some decent wheels

[Holyman]

I am looking to convert the banshee to a trike and wanted a 22 inch or so tire for the rear. As it turns out, I think I may opt for a 325/30-18 which is about 26" tall and 13 inches wide.

We'll see