Inner tube size guide: find the right inner tube
A flat tire is the most common cycling breakdown. With the right inner tube on hand, you're always prepared. But which size do you need? In this guide we explain how to choose the right inner tube.
How to read an inner tube size?
The size is printed on the side of every outer tire. There are two systems:
ETRTO system (most reliable): This is the international standard. The size is expressed as width-diameter in millimeters. For example: 47-622 means 47 mm wide and 622 mm diameter.
Imperial system: This is the old English sizing, still widely used. For example: 28 x 1.75 means 28 inch diameter and 1.75 inch width.
The inner tube must match the outer tire size. The inner tube packaging shows which sizes it fits.
Inner tube size chart
The most common sizes at a glance:
- ETRTO 47-622: 28 x 1.75 (city bike, Dutch bike)
- ETRTO 32-622: 28 x 1.25 (road bike, hybrid)
- ETRTO 37-622: 28 x 1.40 (touring bike, trekking)
- ETRTO 50-559: 26 x 2.00 (mountain bike)
- ETRTO 23-622: 28 x 1.00 (narrow road bike)
- ETRTO 47-507: 24 x 1.75 (kids bike 24 inch)
- ETRTO 40-406: 20 x 1.50 (kids bike 20 inch, folding bike)
Inner tubes often fit a range of sizes. An inner tube with ETRTO 28-47/622 fits all 28 inch tires with a width between 28 and 47 mm.
Which valve do I need?
There are three types of valves. Check which type your bike has:
1. Presta valve (French valve): Thin valve with a screw-on top. Standard on road bikes and many modern bikes. Length varies (40 mm, 60 mm, 80 mm) - measure the rim depth.
2. Schrader valve (car valve): Thicker valve, same as on cars. Standard on mountain bikes and many city bikes. Universal at gas stations and bike pumps.
3. Dunlop valve: An older type of valve, still used on some Dutch bikes. Requires an adapter for pumps with Presta fittings.
Tip: A Presta valve fits in a Schrader rim hole (with an adapter), but not vice versa. Always check which valve you need before buying an inner tube.
Anti-puncture strip: is it worth it?
An anti-puncture strip is a plastic band that sits between the outer tire and inner tube. It protects against punctures from glass, stones and other sharp objects.
Advantages:
- Prevents many punctures
- Cheap and easy to install
- No extra weight
Disadvantages:
- Doesn't protect against all punctures (nails go through)
- Can cause friction and wear the inner tube
- Doesn't replace a good quality outer tire
An anti-puncture strip is a good extra protection for those who cycle a lot in the city, but a quality outer tire is still important.
Tips for patching an inner tube
With a patch kit you can quickly repair a flat tire on the road. Here's how:
- Remove the wheel and take out the inner tube.
- Inflate the inner tube and find the leak (listen or submerge in water).
- Lightly sand the area around the leak with the sandpaper.
- Apply a thin layer of vulcanizing fluid and let dry for 1 minute.
- Place the patch and press firmly.
- Check the inside of the outer tire for sharp objects (especially the cause of the leak).
- Inflate the inner tube, put it back and mount the wheel.
Important: Always check the inside of the outer tire. If you don't remove the sharp object, you'll get another flat.
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Frequently asked questions
How do I know which inner tube size I need?
Look on the side of your outer tire. The size is printed there, in ETRTO (e.g. 47-622) or imperial (e.g. 28 x 1.75). Search for an inner tube that matches this size.
Can I use a narrower inner tube than my outer tire?
A slightly narrower inner tube can work, but one that's too narrow can stretch and puncture more easily. Inner tubes often fit a range, so choose one within your outer tire's range.
Which valve length do I need?
Presta valves come in different lengths. Measure your rim depth and choose a valve that's at least 10 mm longer. For standard rims, 40 mm is usually sufficient. For deep-section rims, you'll need 60 mm or longer.
How often should I replace my inner tube?
An inner tube lasts an average of 1-3 years, depending on use. Replace the tube if you've patched it multiple times, if the rubber feels brittle, or when installing a new outer tire.
Do you carry inner tubes for all bike brands and sizes?
Yes, in our tire collection you'll find inner tubes in all common sizes and valve types. Filter by ETRTO size or wheel size to find the right inner tube.
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