Reversible ratchet

Fahrradwerkzeug

A reversing ratchet (also called a freewheel ratchet or part of the freewheel mechanism ) is a central component in the rear wheel hub of bicycles. It allows the rear wheel to rotate freely without the pedals turning, while simultaneously ensuring that the pedaling force is reliably transferred to the rear wheel.

function

The ratchet mechanism uses small, spring-loaded pawls. When pedaling forward , these pawls engage with a toothed ring (ratchet ring) and transfer the power from the sprocket cluster to the hub and thus to the rear wheel.
When rolling without pedaling, the pawls slide over the teeth – creating the typical freewheel noise – and the wheel can rotate independently of the pedals.

Construction

A classic reversible ratchet consists of:

Locking pawls (usually 2–6 pieces),
Springs that push the latches outwards,
Ratchet ring with fine or coarse teeth,
Freehub body on which the cassette or sprocket is mounted.

Depending on the design and manufacturer, the number of pawls and the tooth density vary significantly.

Importance for driving feel and technology

The design of the ratchet mechanism influences several properties of a bicycle:

Engagement angle : The more toothing points there are, the faster the freewheel engages when starting.
Volume : Finely toothed systems with many jacks are often louder, coarse systems quieter.
Efficiency and durability : High-quality materials and precise mechanics ensure long-lasting power transmission, especially under high load (e.g. in the racing bike or e-bike sector).

Areas of application

Ratchet mechanisms are found in almost all types of bicycles:

racing bikes
Mountain bikes
Trekking and city bikes
E-bikes (often reinforced versions due to higher torque)

maintenance

A reversible ratchet wrench is generally low-maintenance, but should be cleaned and lubricated regularly. Too much or the wrong type of grease can impair the ratchet mechanism, while too little lubrication increases wear and noise.

The term "reversible ratchet" is often used colloquially as a synonym for "freewheel ." However, technically it refers to the mechanical shifting or locking mechanism within the freewheel , not the entire hub.

The reversing ratchet is the mechanical core of the bicycle freewheel and ensures the positive connection when pedaling as well as free rolling without pedal movement.

EQP (Equipped)

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Published: February 2, 2026 | Updated: February 2, 2026

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