Inner Tubes

They are not only a very important part of our bicycle (the wheels wouldn't go round without them), they are also something that we should always carry a spare of. Having a puncture miles from home is bad enough, but having to fix the punctured tube beside the road is something else (we won't even talk about trying to stick patches on in the rain!). It is always easier to just insert a new inner tube.

But what inner tubes are the right inner tubes? There is a bewildering array of numbers associated with buying inner tubes so we've tried to simplify them below to help ensure you get the correct tube.

 Things to consider;

1. Wheel size; the first number in all the descriptions (700, 650 etc) represents the approximate diameter in millimteres of the wheel for which the tube is intended. As a guide, most racing bikes, hybrid and city bikes are approximately 700mm in diameter. Mountain bikes are usually measured in inches rather than millimetres (it's a long story) and are usually 26 inches.

2. Tyre size; the second set of numbers relates to the thickness of the tyre (18-28, 28-32 etc). Put simply, racing bikes will have a tyre size from 18-28 and hybrid and city bikes are larger. You can check the tyre on your bike if you're not sure because this will have the same types of numbers.

3. Inner Tube weight; Unless you're concerned about every last gramme of weight on your bike (it's a racing thing) then we don't suggest you buy lightweight inner tubes. To make them lighter, they make them thinner which can only mean that they are less puncture resistant. Why pay more for less?

4. Valve Type; there are two main types of valve - Presta and Schrader. As a general rule, the higher the pressure tyre, then the more likely it is that you'll have a Presta valve. Schrader valves are more often found on mountain bikes and touring bikes.

5. Valve length; most wheels will accept the standard 40mm valve, but if you own a bike with deep section wheels (time triall or Triathlon bike usually) then you might need to have the longer valves.