page_title: Jockey wheel
section_title: Bicycle Jockey Wheels
hierarchical_section_title: Jockey wheel / Bicycle Jockey Wheels
caption_attribution_description: English: Pulley wheels for a bicycle rear derailleur, Aerozine PL1.0, 7075 aluminium alloy with steel bearings, 11.6 g per pair
context_page_description: The term jockey wheel predominantly refers to a wheel-based mechanical system used for steering or guidance. It is either
  a guide wheel - usually operating as a pair - which is used to move, retain, locate and add tension to a chain, rope or cable which is then fed into the groove of another wheel, toothed wheel, cog or sprocket;
  a retractable, smaller, height-adjustable wheel located on the front of a Trailer_ or Caravan_ for the low-speed manoeuvring or manual steering of said trailer-based unit when decoupled from the powered vehicle to which it was attached.
context_section_description: Although variations exist, most dérailleurs used for changing between the cassette of sprockets - or Cogset - on the rear of a road (race) bicycle or MTB (mountain bike) (collectively known as the gears) have several components in common.  These include the jockey wheels which are held in situ inside a precision-machined vertical cage via steel or ceramic bearings. This cage holds two guide pulleys that locate the chain, almost always in a vertically positioned S-shaped pattern (an 'S' in reverse when viewed from the bike's drive-side). The pulleys are known collectively as the jockey wheels or jockey pulleys - the guide pulley is at the top of the pairing (closest to the sprockets) and the tension pulley is at the bottom, taking any slack up from the bike chain as it is fed from one of the chainset's
  chainring.
caption: Bicycle rear derailleur pulley wheels
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