Billboard diameter inches conversion to metric?
 

I have seen before here on CC, that someone posted a conversion chart from inches like Roger Kraus site, to, as example to 295/50/15. I can't find it ?
Can any of you post a chart ?

I am not sure this will work for what you want but here is a link to a conversion site.

http://www.metric-conversions.org/

Ron

A 295/50/15 between different manufacturers can can have a multitude of different measurements, even if listed as the same size. You have to consult the MFR's specs for that particular tire.. If that's what ultimately you're looking for.

Dave

You can check the sizes of a 295/50-15 at sites like Tire Rack and you will see that they are virtually the same size as the rear "billboard" tire. The front is a 235/60-15.

To get the overall height of the tire, multiply the width by the sidewall aspect. Then divide that by 25.4. That will give you the sidewall height in inches. Multiply that by 2, then add the wheel diameter and you will get the overall height of the tire.

For example:

295/50-15

295*.5 = 147.5mm.

147.5mm / 25.4 = 5.80 (the height of the sidewall)

Overall height = (5.80 * 2 ) + 15 = 26.6"



If you divide the 295 by 25.4, you will get the width of the tire in inches:

295/25.4 = 11.6"

And to think that all of these years I have used that formula and found it was easier to just measure from the floor to the top of the tire when it is mounted and aired up.

Ron :)

This is driving me nuts ! :JEKYLHYDE

I talked to a salesman from Roger Kraus and he gave me these results.

My rears- 295/50/15

Rear on a 10" wheel = apx. 325/45
10" wheel is 12.9" wide.

From the dealer in which were buying the "Group Buy" from told me this yesterday.

27" tall.
12.9" from sidewall to sidewall.
Tread width is 10.2"

I think, my sidewall to sidewall is apx. 13"

To tell you the truth, I don't understand all these measurements and who's correct ?

Since I went to the extent of getting together the group buy, I'll be seriously,....bummed out, if I can't get any.

For me at least, I've worked very hard, on locating a dealer that would work with us, many phone calls, and several hours working on this for us all, they may not fit on my cobra. If his calculations are correct with my 295/50's, the Billboards would be 325/45 and would stick out side of my wheel well. If so, I can not have that. I like the wheel well lip to cover the top of my tires.

Below are some photo's of my new lower stance, that my friend and I worked so hard on achieving, with new shorter QA-1 coil overs, weight scales, all new heim joints ect. I do like how it sits but, with another person with me, i do have some tire rub if hitting a pot hole or rough section on the street/highway.

If I keep my tires, I'll either have to raise the rear up again, which would defeat the purpose of lowering the car, to reduce the space between the tire & wheel well. I could also stiffen the coil overs to reduce the compression rate but, that makes for a harsh ride.

Even though I may not be able to have the Billboards in the group buy, I'm very happy that all of you can. And, it was not,.... a waste of my time !

All of us here on club cobra, do the best we can to help each other out. That's the Cobra brother hood, we all have with each other. :)

http://i43.tinypic.com/1zv4sco.jpg
http://i43.tinypic.com/263c5jq.jpg
http://i42.tinypic.com/316p648.jpg
http://i43.tinypic.com/29ckgfb.jpg

Here are some pics showing just how high the rear was before. If you're capable, zoom in for a closer look. It was way,....too high. And these tires were the taller 60 series

http://i42.tinypic.com/b8wh8n.jpg

http://i41.tinypic.com/sboqp5.jpg

With the conversion calculator (Thank you Ron) I get this result below.
(My tires 295.50/15)

http://www.redrock4x4.com/tech/tire_...&method=metric


Metric Tire Conversion Calculator
Use these calculators to convert metric tire sizes (ie 285/75R16) to standard tire sizes (ie 31x10.50R15) and vice versa.

Metric to Standard Conversion
Enter the tire size below (ex 265/75/16)
/ R

Standard to Metric Conversion
Enter the tire size below (ex 31x10.50/15)
x R



Result:
295/50/15 = 26.6x11.6/15