Jockey pulley

Sheldon Brown's Bicycle Glossary · letter I-L
← Japanese Industrial Standard (J.I.S.) · J.R.A. →

The upper pulley on a rear derailer. This is the pulley that actually guides the chain from one sprocket to another. Shimano jockey pulleys are designed with a "Centeron®" mechanism that allows a small amount of sidewards motion to compensate for imprecise index adjustment.

Copyright © 1996, 2008 Sheldon Brown

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