The inner tube may be a simple part of your bike, but it’s also one of the easiest to get wrong if you don’t know what to look for. There’s a huge range of sizes available, plus differing valves and materials. In order to keep your bike rolling smoothly, you need to make sure you buy the right ones.
Fear not, however, as we’re here with our useful guide on how to choose the right inner tube for your bike, along with some recommendations for the best ones available.
There is no ‘one size fits all’ when it comes to inner tubes, and it’s important to match the size to your wheel’s diameter, and tire’s thickness. This will also depend upon the kind of bike you’re riding, but it really doesn’t have to be as complicated as it may sound. The first thing you need to do is establish which size you need.
Road bikes will generally have a 700c diameter wheel, and so you’ll need a 700c tube to go with it. Many commuter hybrids will have 700c wheels as well.
Mountain bikes, on the other hand, are a bit more variable: their wheels can come in 26in, 27.5in or 29in diameters.
Just to be a little more confusing, gravel and adventure bikes sometimes come with smaller 650b wheels, but this is exactly the same as 27.5 inches.
Children’s bikes will have much smaller wheels, and the sizing depends on the age group and size of the bike. They’ll likely be 16in, 20in or 24in. This also applies to folding bikes.
It’s important to get the diameter right, and from here you also need to establish the width. Thankfully, these are a little more forgiving, with inner tubes covering a range of width sizes. All you need to do is find out the width of your tires, and select a size range that includes yours.
Tire and inner tube widths are measured in millimeters for road bikes, and inches for mountain bikes. As an example, a 700x20-25 sized inner tube will work for a road bike with 23mm tires, while a 27.5x1.75-2.5 sized inner tube will fit a mountain bike tire that’s 27.5in in diameter and 2.35in wide.
Once you’ve worked out the size, the next thing you need to establish is the type of valve you need. The two most common valves used these days are Presta and Schrader valves.
Presta valves are generally more commonly used these days. They’re longer and narrower, and have a screw at the tip, which needs to be undone in order to pump it up. Pressing down on the tip when it’s undone will release air.
The tip of the Presta is actually part of the valve core, and this can sometimes be removed and replaced if it’s damaged. This does mean you need to be careful not to accidentally unscrew the valve core, or bend it when attaching and detaching a pump.
The Schrader valve on the other hand is short and stubby, and looks just like the valves found on car tires. It’s important to get the correct valve, because it must thread through a hole in the wheel’s metal rim. If you buy a tube with a wide Schrader valve for a Presta-compatible rim, it won’t fit.
As well as establishing the correct valve type, if you’re buying a new Presta inner tube, you should consider the length of the valve as well. This is because the majority of the valve needs to poke through the hole in the rim in order to be secured in place and accessible to pumps, but rim depths can also vary. If you have deep section rims, which are becoming more and more common on road bikes these days, then you need to make sure your valve is long enough to poke all the way through.
Valve lengths can go all the way up to 80mm. It’s better to have one too long, rather than too short, but an oversized valve will look a bit odd.
While it can be less common, it is possible to have wheels with rims that are even deeper than the longest valve you can find. If this happens to be the case for you, you can buy a valve extender that screws on top, to add some extra length.
Most inner tubes are made from rubber: either butyl or latex. Latex tubes are lighter in weight, while butyl tubes are more common, heavier, and create additional rolling resistance. They are, however, cheaper than latex. What’s more, they’re also easier to repair using a standard puncture repair kit, so they tend to offer a lot more in longevity. Latex may offer weight savings, but it’s also quite flimsy and fragile, making latex tubes more awkward to fit.