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 e.g. kids bikes come in a range of wheel sizes starting at 12inches…16 inches..20 inches…up to 24 inches.  This is where the adult sizes kick in 26inches, 27.5 and 29inches.

Road bikes are different again their diameter is 650 to 700C (this is not a cm measurement but millimetres, the C is an A to D system).

Width…

means the width of your tyre.  Remember that your tube sits inside your tyre and when it is full of air it is the tube that allows the tyre to hold it’s intended shape.  The width changes depending on the purpose of the bike – generally the wider the tyre the rougher the terrain it is used on.  Skinny or narrow tyres give you smooth fast riding so are great for the road – flat, smooth, even surfaces.

Puncture Protection

There are other types of types other than the standard tube that can add an element of prevention to your ride.  They will save you time out on the trail or on your way to work by either completely preventing a puncture or sealing the puncture immediately.  This added advantage comes at a higher price point but is worth the investment for many types of riders – commuters, mountain bikers, tour riding or anyone that would rather be enjoying their ride than fixing a puncture.  You should, in theory, not have to replace these types of tubes as often as you would standard inner tubes.

Self sealing inner tubes have a sealant inside them.  When you puncture the sealant will fill your puncture hole and harden fixing your problem immediately.  This system works on punctures up to 3mm wide so it is still recommended that you carry a spare tube incase of slashing type flats.  You may also have to rotate your wheel to get the sealant to fill the hole then pump any air you have lost back in.

Thorn resistant inner tubes are 3x as thick as a standard inner tube.  This makes them really durable and strong so they are less likely to puncture.  This type of inner tube is popular with mountain bikers who often find themselves surrounded by gorse.  These tubes are not designed to be carried as a spare tube in a bike tool kit, they are considerably bigger & heavier than standard inner tubes.

Riding Specific

You can also get inner tubes that have been designed to match a certain type of riding.  Downhill inner tubes are durable & strong, designed to handle hard impacts better than a standard inner tube.  Lightweight inner tubes are all about reducing weight allowing a competitive rider to perform better.

Your bike pump needs to match your valve.  Most bike pumps can work with both valves the process is just slightly different – watch our Pumping Up a Bike Tyre video to learn more.  Also note that a presta valve has a nut on the tip that must be unscrewed to allow air to flow.

PSI – POUNDS PER SQUARE INCH

The pressure to inflate your inner tube to, is called PSI (pounds per square inch). You will generally find a range from a minimum to a maximum PSI, again, written on the sidewall of your tyre. Check out the photos below which show a minimum PSI to a maximum PSI on a range of different bikes.  Again if you want to know more about pumping up a bike tube, watch our video.