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A Guide to
Inner Tubes

 
 
Inner tubes are simple but essential – unless you’re riding with tubeless tyres, you’ll always need an inner tube, and carrying spares is always a good idea.

There are many different types of inner tube available so it is important that you get the right tube for your bike, and to suit the riding that you are doing.

The tube needs to fit your tyre to avoid overstretching or pinching, both of which are likely to cause punctures, and the tube material needs to be appropriate for your style of riding.

For competitive road racing or time trial you might want to consider the weight, to gain a performance advantage, whilst for downhill mountain biking puncture protection is likely to be your highest priority.
 
Choosing your inner tube size
 
You must make sure you replace your inner tubes with a tube that is the right size according to the diameter and width for your tyre. The size is almost always written somewhere on the sidewall of the tyre for easy reference.

Inner tubes typically state a wheel diameter and width range for which they will work, e.g. 26 x 1.95-2.125", indicating that the tube is intended to fit a 26 inch tyre with a width of between 1.95 inches and 2.125 inches.

Another example might be 700 x 18-23c, which seems less obvious but 700c is the diameter of Road, Cyclocross, Adventure Road and Hybrid bike wheels, and the numbers relate to the width in millimeters, so 18mm-23mm wide.
 
Material
 
Butyl Rubber
 
Butyl rubber is the industry standard for common replacement inner tubes, offering a relatively cheap and readily available replacement product. Butyl is strong and resistant, and we do offer lightweight versions for those looking for weight savings - the Specialized Turbo range and Continental Supersonic tubes are popular versions.
 
Latex
 
Latex rubber tubes offer slightly enhanced handling characteristics - because latex rubber is slightly more flexible than traditional butyl rubber, the tubes adapt quickly to the tyres changing shape while cornering and on impacts. Latex tubes have also been proven in multiple tests to have lower rolling resistance, making them faster. Latex tubes generally have a thinner wall, offering obvious weight savings.
 
Despite the advantages, it is important to recognise the flaws of Latex. Latex rubber reacts badly to contact with some oils and greases so must be handled carefully in the workshop. Also Latex is more gas permeable than butyl rubber and, as a result, latex rubber tubes do not hold the air as long as butyl based tubes and require more frequent inflation, as well as being fairly fragile and easy to tear when inserting. Despite their flaws, latex tubes are a faster and lighter, so worth the investment if you're aiming to be competitive.
 
Valve Styles
 
Schrader valves
 
These are the same valves used on all automotive tyres and are often referred to as ‘car type’ valves. On bikes, Schrader valves tend to be used on lower pressure tyres, such as children's bikes and mountain bikes. Schrader valves have a core that is sprung loaded, and the central pin can be depressed with a narrow object to release air from the tube. The spring mechanism keeps the valve closed.
 
If you plan fast downhill riding, there are tubes designed for slamming into rocks and obstacles, such as the Onza Downhill inner tubes.
 
Presta valves
 
Usually found on higher pressure tubes such as on a road bike, Presta valves have a slimmer stem, sometimes threaded to accept a locking ring, which holds it tight in the rim drilling. To inflate or deflate via Presta Valve, the top section must be unscrewed, allowing the core of the valve to be free to move. This will allow the valve to open and close. In this ‘high pressure ‘ valve it is the air pressure that shuts the valve and then the closing of the top section that keeps it shut. 
 
Valve Length
 
Presta inner tubes are available in different valve lengths to be appropriate for use in deep section rim profiles. If you have deep section rims, make sure the valve is long enough to extend through the rim hole, and still leave enough valve stem showing to fit the pump onto. Valve extenders can be purchased to make a shorter valve fit, and are also a good idea to carry as an emergency spare if you know your tubes require it.
 
Woods or Dunlop Valves
 
These variations are rarely used on modern bikes, but were once popular and we do still stock them if you need one. They look a little like a cross between the two valves, with a wider lower section, like the Schrader, then a collar and a narrow top section, like the Presta. As the rim drilling is the same for both Woods and Schrader, it is easy to replace the older tubes with the more modern variety.
 
Replacing an inner tube
 
Knowing how to replace an inner tube is of course important when you buy a new one. The good news is that it's easy with a little practice - here's our guide:
 
 
 

 
 
This story was last updated on 09/07/2015

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