What do the symbols on a tire mean? What do the symbols on tires mean for example
kenda nevegal 
(54-559) 
k1010-009  
1113513C   
/\ / 167  (/\ / symbol of two triangles)
NYLON 
I want to find out when my tires should be replaced.
Thanks.
"kenda nevegal"  is the brand and model of tyre
54-559 is the width of the tyre (about 2.1 inches) and diameter of the bead (a 26" MTB tyre)


The other numbers are useless to you.

Curiously, none of those numbers say anything about tyre pressures.