The meaning of motorcycle tire and inner tube size indication

• Motorcycle tire size indication
• Motorcycle inner tube size indication

There are many symbols on a motorcycle tires. usually including: size,brand,tire type(TT/TL),ply rating,load capacity,speed symbols,rotation,the certification ID(such as DOT,ISO,ECE,etc),TWI,sometimes, also have the manufacture’s mold ID.

Tire Sizes indication:

Metric representation for example 110/90-16

• 110：Width Section
• 90: Sidewall of the tire is 90% of width section, which is 99mm
• – : Which means bias tire
• 16：The rim is 16 inches.

Imperial representation for example 3.00-18

• 3.00: Width Section
• – : Which means bias tire
• 17: The rim is 17 inches.

The premise of the above data is that the tire is installed on a standard wheel hub and filled with standard air pressure. But because rubber tires are elasticthe,and the datas still have ±4% errors.

Inner Tube indication:

Acctually,inner tube don’t have metric represention size, because inner tube is circle when inflate pressure. but if you use it in the tire of metric represention size is also ok. Although the shape of the outer tire limits the shape of the inner tube, the inner tube can still play a role due to the wrapping of the outer tire.

Now let’s talk about the load capacity and speed symbol.Every ply rating has the relative load capacity and speed symbols.The details are as follows:

Motorcycle Street Tire Size

Front

Rear

Pry Rating and LI⁄SS Conversion

Load Rating (Load Index:LI)

Speed Rating (Speed Symbol:SS) for Motorcycle use