what do all the markings on a motorcycle tire mean?
There's usually info about the dimensions of the tire, along with the recommended air pressure. You can usually look up the tire manufacturers website and find out what all the numbers mean.
Sometimes it seems as if there should be a codebook to understand all of the information on a tire's sidewall. Using a Bridgestone BT-010 as an example, here's what some of the markings represent. The most important label is the sizing designation, which in this case reads 120/70ZR17. This label indicates section width (120mm), aspect ratio (70 percent), speed rating (Z), construction (R), and wheel diameter (17 inches). For our BT-010, note from the table above that the actual section width is 121mm, and the section height is 69mm. Added to the 20mm bead dimension, overall height is 89mm, giving an aspect ratio of 73 percent. This tire has a speed rating of Z or more than 149mph, and is a radial (R) construction. Following the size label is an additional marking defining the load rating for the tire. In this case, 58W indicates the total load carrying capacity is 520 pounds.
They identify the brand and model, size of the tire, the plant where it was made, the high and low pressure range and the weight and speed rating.
