---
title: "Bicycle: replacing an inner tube"
url: https://perrotta.dev/2025/07/bicycle-replacing-an-inner-tube/
last_updated: 2025-07-26
---


Flat tires happen sooner or later[^1]; in my case, every few months.

You can either patch (fix) the existing inner tube, or replace it with a new one
(<5€). In this post, [patching](https://www.youtube.com/watch?v=T0F_hibWHlU) is
out of scope.

I keep forgetting the right technique to do so, hence here are a few notes.

Whenever time is pressing or patience is low, just pay someone to do it for you.
In my experience, in Germany, the labor costs ~15-20€. For example, it's
possible to do it at [Decathlon](https://www.decathlon.de/), though typically
only during weekdays. With that said, it's more economical (and satisfying!) to
do it yourself.

**Sequence**: (inner) tube -> wheel (rim) -> tire (or tyre)

**Tools**:

- 2 tire levelers. It's possible to do it with a single one, but it's harder.
- A pump. It's possible to postpone filling the tube to the end, but it's
  slightly harder.

## Remove the tube

[Video](https://www.youtube.com/shorts/YpP9qi5fawU).

This is the easier step.

One tire lever is enough.

Hold the lever facing away from you, insert it in the right orientation, and
then slide it alongside the tire.

## Get the right tube

[How To Pick the Correct Tire and Tube Size?](https://www.insportline.eu/advisor/168-how-to-pick-the-correct-tire-and-tube-size):

> **Tire size** is mainly given in inches, with the tires being made in diameters of 12, 14, 16, 18, 20, 22, 24, 26, 27.5, **28** and 29 inches.

> **700**: This denotes the wheel diameter, specifically 700c, which is a common
> size for road, hybrid, and gravel bikes. In the ISO/ETRTO system, this
> corresponds to a 622 mm bead seat diameter.

[Types of Bike Tire Valves Available](https://www.bicycling.com/repair/a20048610/the-difference-between-a-schrader-valve-and-a-presta/):

> Bicycles typically come with one of two types of valves. Schrader valves are
> the most common; they're the same as those used on cars and are found on many
> inexpensive bike models. Most higher-end bicycle tires use Presta, a valve
> specifically designed for bikes. Here's how to tell the difference:

> You can put a Presta-specific tube in a rim drilled for Schrader valves, but
> it's not advisable for anything more than an emergency fix. Tubes and tires
> tend to move slightly on the rim.

- **Schrader**: most common, thicker. Harder to deflate (need a thin, pointy
  object to press down its inner pin).
- Presta: thinner, with a nut at its tip, more modern. Easier to deflate (just
  press down its tip).

There's also another type called "Dunlop", it has similar thickness to
Schrader.

My air pump supports both valve types.

## Insert the tube

[Video](https://www.youtube.com/watch?v=tnP6coXzbLY).

First of all: pay attention to the rotation direction of the wheel and the tire:
they
[should](https://www.reddit.com/r/bikewrench/comments/q61zqa/how_much_does_the_rotation_direction_matter_in/)
align. You only commit this mistake once.

I have more luck by slightly inflating the tube first, and then inserting it in
the wheel (start with the valve). Afterwards, insert the tire in the wheel,
wrapping up the tube.

Inserting the tire first, before the tube, yields failure and despair more often
than I would like.

Do not inflate the tube too much, otherwise it becomes quite hard to add the
tire around it.

Once everything is done, fill in the tube. Pay attention to how much air to pump
in.

See also: [How to change an inner
tube](https://www.youtube.com/watch?v=hKvnaQ_9nG0) end-to-end
([via](https://www.evanscycles.com/buying-guides/inner-tubes)).

[^1]: And even sooner than [death and taxes](https://en.wikipedia.org/wiki/Meet_Joe_Black).