Freewheel

Constant pedalling, even when you aree going downhill, is obviously not a very practical way to cycle. This is why the freewheel was invented. A freewheel interrupts the connection between the chain and the crank, so that when the tyres rotate, the pedals do not rotate with them. But on an e-bike, freewheeling can also mean the interruption of the motor assistance. Learn more about freewheeling on bicycles and e-bikes here.

How exactly does the freewheel work?

A freewheel is a mechanism located in the rear hub of a bicycle. It ensures that the pedal does not automatically rotate in the direction of the rear wheel when it moves. In short, the freewheel decouples the connection between rear hub, chain, sprocket and pedals. This can be achieved in several ways; in the following, we will introduce you to the various types of freewheel.

Ratchet and pawl freewheel

The ratchet and pawl freewheel is the most common type. In this design, the diagonally mounted locking sleeves only catch when you pedal forward. Without a pedalling movement, these only drag without catching; this is what makes the well-known freewheeling noise.

Star ratchet freewheel

With the somewhat more complicated star ratchet freewheel, two toothed discs with slanted teeth are pressed together by means of a spring as long as you pedal. Here, the typical freewheeling noise comes from the toothed discs moving against each other when idling. Significantly more robust than the ratchet and pawl freewheel, the star ratchet freewheel is preferred for bicycles in the freeride and downhill segment. 

Roller freewheel

Unlike the last two types of freewheel, the roller freewheel is very quiet. Here, pedalling presses up to eight pinch rollers against the hub and moves it forward. When the rider does not pedal, there is no pressure on the rollers. These rollers then run freely in their guide tracks, as with a typical ball bearing, and make virtually no noise. 

Sprag clutch freewheel

Another variant is the sprag clutch freewheel. While in one direction of rotation the inner ring can be turned against the outer ring as desired, in the opposite direction of rotation the two rings are locked against each other by the clamping elements.

Why is the freewheel so loud?

In a normal configuration, it is the pawls that are responsible for the noises in the freewheel. The more of them there are, the more sounds they make. In this sense, the volume can be a sign of a particularly high-quality freewheel (with a high number of pawls). However, the decreasing tension of the pawls can also be the reason for louder noises from your freewheel.

How loud a freewheel is also depends on its state of maintenance. Applying oil once or twice a year, such as before and after the cycling season, proves to be effective in controlling the noise. A poorly greased freewheel makes unpleasant noises and ensures faster wear.

What is the best oil for a freewheel?

You can prevent loud clicks and creaks by using the right kind of oil. It is best to use a very low-viscosity oil, which you can buy at a specialist shop. This will prevent the pawls from jamming in the freewheel.

What does the freewheel mean for an e-bike?

E-bikes may also have some form of freewheel system. In addition to the freewheel systems described above, which are also found on conventional bicycles, a freewheel on an e-bike also means that the motor drive on the bicycle is interrupted as soon as you stop pedalling. This does not require a freewheel in the rear wheel, but a freewheel diode in the motor of the e-bike. 

Not every manufacturer offers an e-bike motor with freewheel. However, if you choose this type of drive, you have the option of completely decoupling the motor and drive system: this means that you will be able to pedal freely even in 'off' mode or at speeds of over 25 km/h.