Jockey wheel: considered one of two smaller sprockets with the rear derailleur that guides the chain on to the cassette A bushing are available on possibly side with the roller in certain chains, Though These are rarely found in modern day chains. Copyright, Orion Powersports / Orion Pit Bike Sales, https://bikeengineprice16531.tokka-blog.com/35285365/details-fiction-and-bike-party-sacramento