Bicycle Quill Stem Stuck Due to Bimetallic Corrosion

Identify this cause by observing signs of oxidation, such as white or crusty residue, at the junction where the aluminum stem meets the steel steerer tube. Confirm by verifying that the stem is completely immovable despite the use of force and checking for evidence of galvanic corrosion, where the dissimilar metals have chemically bonded together due to moisture ingress over time.

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