Embossed on the side wall of your tyre you will find all the information you need to know about your inner tube. This is represented in diameter x width e.g. 26 x 2.0 (see the photos above & below).

Diameter…

The diameter is the diameter of your wheel – this changes depending on the type of bike and size of the bike what does your say 12, 16 ,20, 24 (Kids Bikes) or  26, 27.5 and 29 ( Adult Bikes).Road bikes are different again their diameter is 650 to 700C.

Width…

The next number is the width. There are different sized widths to fit the different sized tyres  Inner tubes come range in a range of widths for example 1.90- 2.35. Make sure your width is somewhere in the range. Note your front and rear tyres may have different widths.  What does yours say?.

VALVES – PRESTA & SCHRADER

The valve is where the air goes in to inflate your inner tube.  When you are buying a inner tube replace it with the same valve type that you have. You will either have a presta (skinny, high pressure) or schrader (fat, low pressure) valve.

Presta Valves –  Your Presta valve may have a screw on cap over the end of the valve Presta valves also come in different lengths to match your wheel rim depth. Air flows into the tube when the screw on the end is unscrewed. 

Schrader Valves – The wider thicker valve.  Air flows through the valve when the pin in the centre is compressed/pushed.