Basics of Tyre Marking Details

Editor@Throttle|Updated: December 19, 2017 9:36
Ever wondered what the characters on the side wall of a motorcycle tyre mean? There is a long list of numbers and alphabets but we would like to give you a basic idea on how to read details on commonly used motorcycle tyres.
Front tyres are usually narrower than the rear and a wider tyre doesn’t necessarily mean it puts more rubber on the road which is more a result of the curvature of the tyre. 
Tyre Basics
1. The name of the manufacturer can be seen on the left part
2. Next comes the direction of rotation of rear tyre
3. Next is the tyre size, speed rating, type etc
4. Next is the tyre's model name.
How to read tyre details?
For the tyre marking - 180/55 ZR 17
180 refers to the tyre width in millimeters.
55 refers to the aspect ratio.
Z refers to the speed rating given below.
R refers to radial tyres.
(B stands for belted and R for radial. Belted tyres are reinforced with materials such as Kevlar for extra strength and load.)
17 is the rim diameter in inches.
For the tyre marking 170/80 -15M/C 77 H TL 
170 is section width in millimeters
80 is aspect ratio
15 is rim diameter in inches
M/C refers to motorcycle tyre
77 is Load Index
H is the Speed Rating
TT stands for tubed tyres
TL stands for tubeless
Reference Table:
Speed Rating & Load Index :
This code, when present, appears after the size marking. The code comprises three characters: two numbers and a letter, for example, 67H.The two-digit number is a code for the maximum load carrying capacity of the tire. The letter is a maximum speed rating indicating the maximum speed at which the tire may be used with maximum load when the maximum listed inflation pressure is used. 
Article Source : Michelin