| Author | Message | ||
     M1combat |
I need a set of tires. I'm willing to gather all the data on the tire sizes. I'm willing to generate an Excel spread sheet that will manipulate the data. What I'm trying to do is gather the width, diameter and size of all the 180/55X17 and 120/70X17 tires and get Excel to graph the profile of each tire for me. I understand that many tires don't have perfectly rounded profiles but I think I can deal with that later... I need to know a few things... On 180/55X17 tires - First, I need to know if my head is on straight... The "55" is a ratio based upon the width (we get 99 in this case). Is that to the outside edge of the tread from the bead or to the top of the tread (center of the tire) from the bead? Thank in advance, I'll have more questions later I'm sure. | ||
| Wyckedflesh |
That will vary from maker to maker. Some will measure from bead to edge, and others will make an imaginary line that goes from the bead straight up til the edge of the tread. So it doesn't count the part of the tread that extends past the bead and rim edge. | ||
| Fullpower |
M1 are you real bored at work today? | ||
| Lightisright |
There are tire guidelines for the size and how they are measured. The T&RA (Tire and Rim Assoc) puts out these. All measurements are taken with the tires mounted on the design rim width (5.5 for 180/55R17). The 180 is the overall straight line width of the tire in mm. The 55 is the tire is 55% tall as it is wide (measured from the bottom of the bead to the 'crown' of the tire. Because there is a tolerance given to the width measurements, there are wide 180s and narrow 180s, which then effects the diameter. You just have to measure each one. Most manuf. give the dimensions of their tires on their website. | ||
| M1combat |
So the 55% DOES go out to the center... Is there a standard for actual sidewall height? | ||
| Lightisright |
No, actual sidewall height can be whatever the manuf. wants. |
