How to change a bicycle inner tube step by step: complete guide to get it right

A flat tire can turn a pleasant bike ride into a real nuisance. The good news? Changing the inner tube is a simple operation that anyone can learn in a few minutes. With the right tools and a few precautions, it is possible to get back on the bike quickly, avoiding the most common mistakes such as pinching the inner tube during installation.

In this guide, you will discover how to choose the right inner tube, which tools to use, how to replace it even on bikes with disc brakes or e-bikes, and all the advice needed to perform the work correctly.

How to choose the correct inner tube for your bike?

The first rule is simple: the inner tube must be compatible with the tire.

To choose the right one, you must consider three elements:

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

Each inner tube lists a range of compatible sizes. For example, a tube marked as 700x25-32C is suitable for 700C tires with a width 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 create folds inside the tire.

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

Dimensions can be indicated using different standards.

The most common are:

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

The ETRTO code is the most precise.

For example:

37-622

means:

• 37 mm tire width;
• 622 mm internal rim diameter.

If you are unsure, just check the tire sidewall: you will always find the correct size there.

How to determine the inner tube size by looking at the tire?

It is not necessary to remove the wheel.

All the necessary information is printed on the side of the tire, for example:

• 700x28C
• 700x35C
• 29x2.25
• 27.5x2.10
• 37-622

These data allow you to purchase a perfectly compatible inner tube.

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

There are three most common valve types.

Presta Valve (French)

• thin;
• used on road and gravel bikes;
• works with high pressures;
• requires unscrewing the small nut before inflation.

Schrader Valve (American)

• identical to those on cars;
• more robust;
• very common on MTBs, city bikes, and e-bikes.

Dunlop Valve

• less common;
• found especially on traditional or city bicycles.

There are also inner tubes made of different materials:

• butyl (the most common and economical);
• latex (lighter and more performant, but require frequent inflation);
• TPU (extremely light and compact, increasingly popular among sport cyclists).

What is needed to change the inner tube?

Preparing all the necessary items makes the work much simpler.

The essential tools are:

• new inner tube;
• plastic tire levers;
• pump or mini compressor;
• repair kit (useful for emergencies);
• work gloves (optional).

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?

Once you have prepared the tools, you can proceed following these steps.

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. Fully deflate the tire

Even if the tube is punctured, ensure it is completely empty of air.

3. Use tire levers

Insert the first lever under the tire bead and hook it to a spoke.

Using the second lever, slide the bead over until one side of the tire is free.

4. Remove the inner tube

Remove the valve first, then pull out the entire tube.

5. Check the tire

Before mounting the new tube, run your fingers slowly inside the tire.

Verify that there are no:

• thorns;
• glass shards;
• wire fragments;
• debris.

If any foreign object remains, the new tube will puncture immediately.

6. Insert the new tube

Inflate it slightly before installation.

This small trick allows it to keep its shape and prevents folding.

Insert the valve first, then evenly distribute the entire tube.

7. Remount the tire

Close the tire using your hands.

Use tire levers only if strictly necessary.

8. Inflate to the correct pressure

Check the recommended pressure printed on the tire.

Correct pressure improves comfort, smoothness, and reduces the risk of new punctures.

How to change the rear wheel inner tube?

The rear wheel requires a bit more attention.

Before removing it:

• shift the gears to the smallest cog;
• release the wheel;
• gently guide the derailleur outward.

During reinstallation, ensure the chain correctly returns to the cog.

On bikes with a hub motor, you must disconnect any electrical connector following the manufacturer's instructions.

How to use tire levers correctly without causing damage?

Tire levers are a simple tool, but they are often used incorrectly.

To avoid damage:

• use plastic levers;
• insert them only under the tire bead;
• avoid pushing deep where the tube is located;
• do not apply excessive force when prying.

Metal levers can scratch the rim and easily pinch the inner tube.

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;
• be careful not to bend the disc.

For e-bikes:

• always turn off the bike;
• remove the battery if possible;
• disconnect any motor cables following the manual;
• be mindful of the wheel's increased 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 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 some particular models or using specialized open inner tubes, but on most bicycles, it is necessary to remove at least one wheel.

How to avoid pinching the inner tube during installation?

This is one of the most frequent errors.

To avoid it:

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

A quick final inspection can prevent a new puncture right after you set off.

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

An inner tube can last several years if it is not damaged.

It is advisable to replace it when:

• it has multiple punctures;
• the rubber has become dry or cracked;
• the valve is damaged;
• repairs are becoming numerous.

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

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

If the wheel slowly loses pressure, the cause may be different.

To identify it:

• inflate the tube;
• submerge it in water;
• look for bubbles.

If bubbles come out of the rubber, the tube is punctured.

If they come from the base or inside the valve, it may be the valve that is defective.

Also check that the tire and rim tape are intact.

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

A spare tube takes up very little space and can save any ride.

You can carry it:

• in the seat bag;
• in a small frame bag;
• in a backpack;
• in a jersey pocket.

Ideally, pair it always with:

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

In this way, you will be ready to face almost any puncture.

Conclusion

Knowing how to change a bicycle inner tube is one of the most useful skills for any cyclist, from beginners to MTB or road bike enthusiasts. Knowing the correct size, using the appropriate tools, and following an orderly procedure allows you to complete the intervention in a few minutes and set off without stress.

Remember that prevention is equally important: regularly checking the condition of the tires, maintaining the correct pressure, and always carrying a spare inner tube significantly reduces the risk of being stranded during a ride. A small investment in maintenance that can make a big difference, whether on short daily rides or long adventures on the road or trails.