A flat tire can turn a pleasant bike ride into a real nuisance. The good news? Replacing the inner tube is a simple operation that anyone can learn in a few minutes.

In this guide, you will discover how to choose the right inner tube, which tools to use, how to replace it on bikes with disc brakes or e-bikes, and all the tips to do the job correctly.

How to choose the correct inner tube for your bike?

First of all, the inner tube must be compatible with the tire. To understand this, you need to consider three elements:

• the wheel diameter
• the tire width
• the valve type.

Every inner tube lists a range of compatible sizes. For example, an inner tube marked 700x25-32C is suitable for 700C tires with widths between 25 and 32 mm.

If you use an MTB, you might find sizes like 29x2.10-2.40 or 27.5x2.20-2.50.

It is important not to choose a tube that is too small or too large: an overly stretched tube will be more prone to punctures, while one that is too wide will tend to fold inside the tire.

How to read and measure the dimensions of an inner tube?

Dimensions, found on the side of the tire, can be indicated using different standards. The most common are:

• ETRTO system (e.g., 37-622);
• inch measurement (26x1.95);
• French measurement (700x28C).

What are the different types of valves and available inner tubes?

There are three most common valve types.

1. Presta Valve (French)

Thin, used on road and gravel bikes and works with high pressures.

2. Schrader Valve (American)

More robust and very common on MTB, city bikes, and e-bikes.

3. Dunlop Valve

Found mainly on traditional or city bikes.

Additionally, there are inner tubes made of different materials:

• Butyl -> the most common and economical
• Latex -> lighter and more performant, but require frequent inflation
• TPU -> extremely lightweight and compact, increasingly popular among sport cyclists.

When is it necessary to replace the inner tube and how long does it last?

An inner tube can last several years if not damaged; however, it is advisable to replace it when: it has multiple punctures, the rubber becomes dry or cracked, the valve is damaged, and/or repairs are becoming numerous.

If the puncture is single and the tube is in good condition, a quality patch can easily extend its life.

How to tell if the inner tube is punctured or if the valve is faulty?

If the wheel loses pressure slowly, the cause can be of two types. To understand which, it is advisable to: inflate the tube, immerse it in water, and observe the presence of bubbles:

1. If bubbles come from the rubber, the tube is punctured.

2. If they come from the base or inside the valve, the valve might be faulty.

❗Also check that the tire and rim tape are intact.

What is needed to change the inner tube?

The essential tools for changing an inner tube are:

✅ New inner tube

✅ plastic tire levers

✅ pump or mini compressor

✅ repair kit (useful as an emergency)

For e-bikes, it may also be useful to have the appropriate keys to remove the wheel axle.

How to change the bicycle inner tube step by step?

In the case of the front wheel:

1. Remove the wheel

If the bike has a quick release, open it; if it uses nuts or through-axles, unscrew them with the correct tool.

2. Deflate the tire completely

Even if the tube is punctured, ensure it is completely deflated.

3. Use the tire levers

Insert the first lever under the tire bead and hook it to a spoke. With the second lever, slide the edge to free one side of the tire.

4. Remove the inner tube

Remove the valve first and then pull the tube out completely.

5. Check the tire

Before mounting the new tube, run your fingers slowly inside the tire to verify there are no: thorns, glass, metal wires, or shards.

⚠️ If a foreign object remains, the new tube will be punctured immediately.

6. Insert the new tube

Inflate it slightly before mounting so you can maintain its shape and avoid folding.

Insert the valve first and then distribute the tube evenly.

7. Remount the tire

Close the tire working mainly with your hands.

⚠️ Use tire levers only if absolutely necessary.

8. Inflate to the correct pressure

Check the pressure printed on the tire and inflate without exceeding the indicated value.

 

In the case of the rear wheel, before removing it you must:

1. Shift the gears to the smallest cog

2. Release the wheel

3. Gently guide the derailleur outward.

4. Follow the steps for the front wheel

❗During reassembly, ensure the chain is correctly seated on the cog.

How to use tire levers correctly without causing damage?

Tire levers are a simple tool but are often used incorrectly. Since they are sometimes metal, they can damage the rim and the tube.

To avoid damage: use plastic tire levers, insert them only under the tire bead, avoid pushing deep where the tube is located, and do not lever with excessive force.

Consequently, to avoid pinching the inner tube, we recommend:

• inflate the tube slightly before installation;
• insert it completely inside the tire;
• close the tire mainly with hands;
• check the entire edge before final inflation;
• inflate gradually, verifying that the tire rises evenly on the rim.

How to change the inner tube on bikes with disc brakes or e-bikes?

The procedure is practically identical to that of traditional bicycles, but there are some precautions.

For bikes with disc brakes: avoid pressing the brake lever when the wheel is removed and take care not to bend the disc.

For e-bikes: always turn off the bike, remove the battery when possible, disconnect any motor cables following the manual, and be aware of the increased wheel weight.

Is it possible to change the inner tube without tools or without removing the wheel?

In some cases, it is possible to remove the tire using only your hands, especially if it is very soft; however, having at least a pair of tire levers makes the operation much simpler.

Without removing the wheel, it is only possible to intervene on certain special models or by using open inner tubes designed for this purpose, but in most bicycles, it is necessary to remove at least one wheel.

How to carry a spare inner tube during bike or MTB rides?

A spare tube takes up very little space and can save any ride; you can carry it: in the saddle bag, in a small frame bag, in a backpack, or in a pocket of your cycling jersey.

Ideally, it should always be paired with:

• two tire levers;
• a mini pump or CO₂ cartridge;
• a repair kit;
• a multitool.

In this way, you will be ready to handle virtually any puncture.

Remember that prevention is key: periodically checking the condition of tires, maintaining the correct pressure, and always carrying a spare inner tube significantly reduces the risk of being stranded during a ride. Maintenance can make a great difference, whether for short daily rides or long adventures on roads or trails.