GENERALLY,THERE ARE TWO STANDARD WAYS TO MARK THE SIZE OF A MOTORCYCLE TIRE,ONE IS MARKED BY INCH(SUCH AS 2.50-17, 3.00-18) ,ANOTHER WAY IS MARKED BY MM(SUCH AS 80/90-18,80/100-21),NOW LET HONEST MOTOR TELL YOU HOW TO DISTINGUISH THESE SIZES,FIRSTLY,LET’S MAKE SOME DATAS CLEAR BY CHECKING THE FOLLOWING PHOTO:

NOW LET’S EXPLAIN IN DETAILS ABOUT TWO TYPE OF THE MARK:

80/90-18
80:IT MEANS THE WIDTH OF THE TIRE IS 80mm.
90:IT MEANS THE ASPECT RATIO IS 90%,WHICH EQUAL TO 80*90%=72mm.
18:IT MEANS THE DEAMETER OF THE TIRE/WHEEL IS 18 INCH.
3.00-18
3.00: IT MEANS THE WIDTH OF THE TIRE IS 3.00 INCH(EQUAL TO 76.2mm)
18 : THIS MEANS THE DIAMETER OF THE TIRE/WHEEL IS 18 INCH.
TIPS:THE ASPECT RATIO OF THE TIRE MARKED IN THIS WAY IS 100%(EQUAL TO 76.2*100%=76.2mm),THAT IS TO SAY, 3.00-18=76.2/100-18

SO NOW ,CAN YOU TELL ME WHICH TIRE IS WIDER(80/90-18 or 3.00-18 )?WRITE TO INFO@HONESTMOTOR.NET TO GET MORE ,WE ARE AT YOUR SERVICE 7*24H.