Cogset: yet another phrase for the set of rear sprockets that attaches to the hub on the rear wheel and normally both a freewheel or cassette Hanger: part of frame or an attachment to your frame to which the derailleur is connected (see Derailleur hanger) 【Effortless to Install】Motorized bike package https://bike-engine-types72208.look4blog.com/73223774/bike-engine-details-things-to-know-before-you-buy