Look a little closer
See the mechanism
Catch to drive, slip to coast
Read the diagram
Left: the chain-driven sprocket turns until a steep tooth face bears against a pawl, carrying the hub and wheel forward. Right: the wheel and its pawl carrier overrun the sprocket; the pawl follows the sloping faces and resets, permitting coasting.
Local contact model, unrolled and not to scale; the actual teeth form a ring. Arrows show direction only. This depicts a pawl freewheel, not a fixed gear. Some hubs use face ratchets instead of pawls.
Diagram basis: US4840084A: operation; DT Swiss: ratchet systems.
Sources: Park Tool · DT Swiss — original manual hosted by FFWD USA · DT Swiss · Sheldon Brown — firsthand technical explanation, maintained by Harris Cyclery
The wheel and sprockets need not move together
Pedaling pulls the chain, which turns a rear sprocket. For that effort to propel the bicycle, the sprocket must transmit torque to the rear wheel. During coasting, however, the wheel keeps rotating while the chain and cranks can stay still. The clutch permits these two behaviors.
Park Tool distinguishes a thread-on freewheel, whose sprockets and ratcheting mechanism form one unit, from a cassette carried on a freehub. With a cassette system, removing the sprockets leaves the freehub mechanism at the hub. These are different assemblies serving the same basic coasting task.
Sources: Park Tool
Think in relative motion
The important comparison is not simply clockwise versus counterclockwise. It is which part is trying to move ahead of the other. When the sprockets drive, the clutch engages. When the wheel overruns the sprockets, the mechanism permits relative movement instead of forcing the pedals around.
This also avoids a confusing shortcut: coasting does not require the wheel to reverse. Both driving and coasting happen while the bicycle travels forward. The changing condition is the connection between the rotating wheel and its input, not the direction of travel.
Sources: Park Tool
One function, different hardware
In a pawl arrangement, small spring-loaded catches engage a toothed member to transmit drive and pass over the teeth during overrun. DT Swiss also makes face-ratchet systems, where toothed faces engage with one another instead of relying on individual pawls. Its Ratchet LN documentation explicitly distinguishes these families.
The schematic shows the pawl idea as an example. It should not be read as a cutaway of every hub, nor as a comparison of their reliability. DT Swiss's claims about its own products are not independent tests establishing that one architecture always wins.
Sources: DT Swiss — original manual hosted by FFWD USA · DT Swiss
The useful exception: fixed gear
A fixed-gear bicycle connects the rear sprocket to the wheel without a freewheel. Sheldon Brown's account makes the consequence explicit: the rider cannot coast with the pedals stationary. As the rear wheel turns, the chain drives the cranks as well.
Single speed is a different description: it counts gear ratios, rather than specifying whether the drive can freewheel. Do not infer coasting behavior just by counting sprockets. When reading a bicycle description, look for fixed gear or freewheel as well as the number of speeds. Those terms answer different questions about the machine.
Sources: Sheldon Brown — firsthand technical explanation, maintained by Harris Cyclery
The thing to remember
Coasting comes from a connection that transmits drive while allowing the wheel to overrun its input.
What this example leaves out
This explains freewheeling drivetrains and contrasts fixed gear. The pawl schematic is one example, without a specified hub or engagement angle. It is not a hub-service guide, and sound alone does not identify an internal design.
Sources & further reading
Source access dates are listed below. Manufacturer descriptions and patents support the specific constructions described, not every product.
- Freewheel Removal and Installation — Getting Started ↗
Park Tool · Retrieved 2026-10-14 · Freehub as a clutch that permits coasting and transmits pedaling drive; distinction between splined cassette/freehub and thread-on freewheel assemblies.
Mechanism and assembly distinctions only. Clockwise descriptions depend on viewpoint, so article uses relative drive/overrun instead. Tool instructions, market-prevalence assertions and repair steps omitted. - Pawl Hubs [370, 370TA] Technical Manual — V2015.04 EN ↗
DT Swiss — original manual hosted by FFWD USA · Retrieved 2026-10-14 · Corroborating mechanism and diagram evidence: pawls, pawl springs and toothed ring hardware; two- and three-pawl construction examples, pages 20–44.
Direct corroboration of the article's pawl example; model-specific 2015 manual, not current universal hub-service guidance. No service procedure or technical drawing reused. - Ratchet LN Technology ↗
DT Swiss · Retrieved 2026-10-14 · Distinction between pawl freehubs and face-ratchet system; toothed faces engage simultaneously; conversion documentation establishes separate hardware families.
Manufacturer primary documentation of its architectures. Reliability superiority and engagement-angle marketing are not treated as independent findings. Pawl motion is a simplified mechanical interpretation corroborated against the DT Swiss Pawl Hubs technical manual. - Fixed Gear Bicycles for the Road ↗
Sheldon Brown — firsthand technical explanation, maintained by Harris Cyclery · Retrieved 2026-10-14 · Fixed-gear bikes cannot coast with stationary pedals; direct rear-wheel/drivetrain connection; distinction from freewheeling single-speed bikes.
Direct authored technical account, not a regulatory or safety source. Riding recommendations, brake advice and subjective benefits are not reproduced.
