Bike Inner Tubes: Size, Valve Type and Material Description
Bike Inner Tubes: Size, Valve Type and Material Description
It’s one of those bike gear that looks simple and standardized. However, bike inner tubes are much more than what is seen. We pull back on rubber and dig into how to make the best bike inner tube, and how to find the perfect match.
There are a lot of variables when it comes to the most insidious elements in a bike. From size to valve type, weight to puncture resistance, finding the right inner tube can make a huge difference to your ride.
Before we go on to share our top tips on finding the perfect inner tube, you have to feel confident about how to fix a puncture and mend your inner tube to ensure you come home safe and sound from your ride.
Inner tube size
When it comes to inner tubes, size does matter. There are two sizes you need to know to make sure you’re buying the right tube for your bike’s wheels and tires.
Inner tube size diameter:
The first is the diameter of the tube. Most of the best road bikes have 700c wheels that require 700c tubes to fit.
However, more other diameter bike wheels have appeared recently, and some of the best gravel bikes come with a choice of 650b or 700c wheels. It’s also the size used by the smaller sizes of the best hybrid bikes, as it leaves room for a larger, more forgiving tire or a deeper tread pattern for more muddy riding.
Checking your bike’s current wheel diameter size is very simple, as the rim, or existing tires will have this imprint somewhere, or you can check your model directly with the brand.
If you don’t see any labels, you can always measure the distance from the center of the wheel to the edge of the tire in millimeters and multiply it by 2 to get the wheel diameter.
If you don’t know your wheel size, this exercise will likely give you your first up-close look at the moving parts on your bike. You may now wonder if these need to be replaced as well.
Don’t panic, now that you know what diameter wheel you have, you can read more about the best road bike tires or more about our review of the best road bike wheels for more on replacing these Tire tips and tricks.
Inner tube size width:
Next is the width of the tube. Many 700c tubes can be fitted with tires up to 25mm in width, which are commonly installed on road bikes, although even 28mm tires are becoming more common on road bikes.
Off-road and gravel bikes, as well as many city and hybrid bikes with 700c wheels, will still have wider tires.Using the correct tube width size is as important as the diameter size.
Bicycle tubes for narrower tires usually fit these wider tires; they are only stretched a little to fill the space. They’re less likely to burst, but if you get a unit, they’ll probably fall faster. On the other hand, wider tubes can be difficult to fit into 25mm tires.
By choosing the right tire and tube combination, you can ensure optimum performance without preventable blowouts.
Word of warning, before you invest in a great tire and tube bundle deal, you’ll also want to make sure your rims fit the width and that the wheels will still spin in your bike without dirtying the frame.
Here is a close-up photo of a wheel showing the label on the tire. It says Maxxis RE-FUSE, which is the make and model, then 700x40c, which is the diameter and width of the tire, 75 MAZ PSI, and finally some logos to indicate some of the characteristics of the tire.
This tire tells you it’s 700mm in diameter and 40c wide
Again, just like figuring out the required tube diameter, the width of the tube will be on your bike’s existing tires, usually the same size as the diameter. It will read something like 700x25c, which means 700 diameter wheels and 25mm tires.
Our sister site MBR has a lot of useful information on the best mountain bike tires, including their dimensions, usually in inches. So a 29-inch MTB tube is the same diameter as a 700c wheel, and a 27.5-inch tube is the same diameter as a 650b wheel. You can also get 26″ MTB tubes. But since MTB tires are usually wider than road tires, they can be too wide to fit even one of the best gravel bike tires.
Mountain bike tire sizes are usually measured in inches. So a 29-inch MTB tube is the same diameter as a 700c wheel, and a 27.5-inch tube is the same diameter as a 650b wheel. You can also get 26″ MTB tubes. But since MTB tires are generally wider than road tires, they may be too wide to fit, even in gravel bike tires.
American valve inner tube
Some bicycle tubes have American valves, like those used on car tires. These are not suitable for wheels drilled for presta valves. Also, if your wheel has a valve hole that fits a US valve, the presta valve won’t fit securely and the tube could get caught in the valve hole and burst.
American valves are huge, and as mentioned above, you’ll need your rim to install one. This isn’t a problem on mountain bikes with wider rims, but on road bikes it’s not ideal to put a large hole in the rim to fit it.
That said, there are still some benefits to running the schrader valve if you can:
American style valves are for industrial use, as seen on cars and trucks, so assuming you don’t have an apartment that can’t be repaired, they will last for years.
They are less prone to bending/need to replace internal parts.
You can quickly suck in a lot of air with the right pump and inflate them with the same pump as your car.
This image is a close-up of a Woods Valve bicycle inner tube that goes through the rim of a bicycle wheel
Woods valve inner tube
There is actually a third valve option, the Woods valve, aka Dunlop valve. It is rarer than presta and schrader. This looks like a presta valve but has a collar that holds the spool in place.
Depending on your point of view, this is the best or worst option for the best of both worlds. If you’re considering it, keep in mind that your wheels need to accept the same size valve as the Schrader, and not all modern pumps will fit Woods valves because of the collars.
The benefits of Woods valve inner tubes are limited:
Less likely to bend than presta valve when pumping to high pressure
Able to release a little air pressure like a French valve
For riders who like presta, but with schrader sized holes in the rims.
Bicycle tube rides may require valve extenders like the four in the photo. They are all different lengths over a period of time background
A valve extender can be a lifeline if your valve isn’t sticking out of the rim long enough to securely attach the bike pump.
Valve Lengths and Valve Extenders
The last thing to consider when buying an inner tube is valve length. If you have deep section wheels, you will need bike tubes with longer valves to ensure they stick out of the rim. Some valves can be as long as 8 cm. And you don’t want to find out while riding that the valve on the stock tube isn’t long enough to connect to the pump – trust us, we’ve done that.
If you think this might work for your next pair of wheels and wondering how to choose the perfect rim depth for you? Follow the link to the page to learn more about choosing the perfect match.
If your valve is still not long enough for your deep wheels, you can buy a valve extender. These screws attach to the valve and add enough extra length to fit the deepest aero wheels.
You can easily buy these for presta valves, but they are fairly rare for schrader valves, and I personally haven’t come across wood valves, but I’m sure someone has made one if you search hard enough.
Rubber & Latex Bicycle Inner Tubes
Most inner tubes will be made of butyl rubber. It is the cheapest material and the strongest. The butyl tube is black and can be repaired with a standard piercing kit if you get a flat one.
Tube manufacturers also typically have lighter weight butyl tubes in their lineup. These are just made of thinner rubber. However, the weight savings comes at the cost of being more flimsy, so you need to be more careful not to pinch it when installing the lightweight tube. They may also be easier to pierce. Bicycle inner tubes can be made of latex, like the red in the image, folded up, on a white background.
Finally, there are latex tubes. These are the lightest options and roll faster than butyl rubber. But they are more fragile and harder to install than lightweight butyl pipes. And they leak air faster than butyl tubes, so you’ll need to re-inflate them before every ride. If they get a unit, they usually can’t fix it either.
We have a page dedicated to thinking about latex inner tubes worth the trouble? It’s well worth a visit if you’re considering a purchase.
Also be careful with latex tubes in rim brake carbon pinch wheels. Since carbon fiber rims don’t transfer heat as fast as alloy rims, prolonged braking on downhills can cause hot spots on the rims, which can damage the tubes and cause failure.
This is unlikely to be a problem if you don’t drag the brakes when descending, but if you’re an inexperienced descender, it’s something to be aware of.
Where to buy bicycle inner tubes? You can buy inner tubes from any bike shop and the staff will be able to help you find the right size, width, material and brand. If you feel more confident then you can easily order online too.
Tubeless Bicycle Tires
While this page is devoted to all things inner tubes, let alone removing them all in favor of tubeless would be an oversight on our part. Mountain bikes have been around for a while, and there are more and more tubeless tires on road bikes.
To run tubeless, you need to have tubeless wheels and tires ready. More new road bikes come with tubeless wheelsets, and most aftermarket wheelsets you can buy are also tubeless compatible. If you don’t have both, don’t try to set up tubeless as you run the risk of a puncture while riding. Tubeless Tires Worth Giving Us: Are You Doing It Right? Suggested pages to read to help you with any conversion issues.
Tubeless tires use a separate presta valve that screws into the rim and has rubber ends for sealing. With the valve in the rim, install the tubeless tire. This is a tighter bead than a regular tire, making it difficult to put it on the rim.
You’ll also want to buy some of the best tubeless sealants to make sure you stay inflated and puncture-free for as long as possible.
Hermetic sealing of the rim can also be tricky. You need to add sealant to the tires. This helps make the tire airtight and usually handles small punctures while riding.
But it may not successfully seal larger holes, so it’s best to carry a spare tube, tire lever, and pump in case a serious leak occurs.
No matter what tire and tube or tubeless setup you use, always ride with a spare tube and pump.
The sealant will dry out over time, so you may need to top it up. That’s where the removable spool comes in. Most sealants come with a nozzle that allows you to spray the sealant through the valve once the spool is removed. Milkit also sells an internal valve kit that lets you check sealant levels and top it up through the valve, which you can buy directly on Amazon.
Solid rubber tires
There’s also an option of puncture-resistant solid rubber tires that will forever get rid of tube problems, though we found ride quality while testing the Tannus Aither 1.1 25mm solid tires.
Are all solid tires worth trying? We weighed the pros and cons of riding especially in winter and found the appeal to be limited, but solid rubber tires won’t be your bike’s first choice until you develop the structure and feel of the ride.
Puncture resistant bicycle inner tube
If your tube has a removable core, you can get extra puncture protection by adding sealant. You remove the core, add about 25 to 30 ml of sealant and reinstall the core. Again, this might not handle the biggest holes, but it might help you keep going. However, if you’re flat, the sealant may prevent the patch from sticking to the tube, so it’s a good idea to bring a spare to take home with you.
We’ve picked out our favorites in our buyer’s guide to the best puncture-resistant tires, and include lots of helpful tips and tricks to help you find the best option.
Watch out for latex tubes though, as some sealants can degrade latex over time, causing it to fail. This can also be an issue with tubular tires, where the inner tube sewn into the tire is often thin and made of latex.
Finally, you can buy bike inner tubes that are already filled with sealant for some extra puncture protection easily.
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