Park Tool DAG-2.2 Derailleur Alignment Gauge

Park Tool DAG-2.2 Derailleur Alignment Gauge Park Tool

Park Tool DAG-2.2 Derailleur Alignment Gauge

Park Tool DAG-2.2 Derailleur Alignment Gauge

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How Does the DAG-2.2 Derailleur Alignment Gauge Work?

The Park Tool DAG-2.2 Derailleur Alignment Gauge is used to check and correct the alignment of the rear derailleur hanger, the critical interface between your frame and rear derailleur that takes the brunt of impact in a crash or wheel removal. The gauge mounts to the derailleur hanger thread and uses a long arm with a reference indicator to measure deviation from true vertical and lateral alignment relative to the rim. Precise hanger alignment is the foundation of clean shifting, and even small bends in the hanger cause indexing problems that cable adjustments alone can't fix.

A bent derailleur hanger is often the first thing to check when shifting becomes erratic or a bike stops indexing correctly after a crash or transport incident. The DAG-2.2 takes the guesswork out of hanger alignment by giving you a direct visual reference for how bent the hanger is and confirming when it's been fully corrected.

$84.95
$84.95
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  • Orders over $100 ship free!
  • Estimated delivery: Jul 19 - Jul 23

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Specifications

  • Function: Derailleur hanger alignment check and correction
  • Mount: Threads into derailleur hanger
  • Compatible: Road, gravel, and mountain bike derailleur hangers (standard thread)

FAQ

How do I know if my derailleur hanger is bent?

Common signs include shifting that was fine before a crash, difficulty indexing across the full cassette, or a derailleur that sits at an odd angle relative to the wheel.

Can a bent hanger be straightened or does it need replacement?

Minor bends can often be straightened using the DAG-2.2. Severely bent or cracked hangers should always be replaced, as repeated bending weakens the material.

Is the DAG-2.2 compatible with all derailleur hanger sizes?

The DAG-2.2 uses standard M10 derailleur hanger thread and fits the vast majority of road and mountain bike derailleur hangers. Verify hanger thread size before use.

Best For

Shop mechanics and serious home wrenchers who do regular frame and drivetrain service. An essential diagnostic tool for any shop that sees bikes after crashes or poor bike transport.

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