Cassette: a bunch of stacked sprockets or gears about the rear wheel of a bicycle with a rear derailleur. There could be between five to 12 gears in back with a cassette. The parts that the engine will come with are of high high-quality and may last for many years. https://bike-engine-guard48034.theideasblog.com/35525275/the-single-best-strategy-to-use-for-lift-chair-positions