It delivers a realistic, accurate, and quiet indoor training experience by using the proven flywheel technology and advanced algorithms of Wahoo's legendary indoor bike trainers. The KICKR CORE indoor trainer is built with the durabilty to withstand all of your indoor training sessions and no other brand of smart trainers has more apps and software training options, including Wahoo SYSTM, Zwift, and Trainer Road.The Wahoo KICKR CORE comes with a pre-installed cassette to match the gears on your bike, which can be selected to work with 8, 9, 10, 11 or 12 speed derailleurs..PLEASE NOTE: Some assembly is required.OPTIMIZED FLYWHEEL TECHNOLOGYKICKR CORE features a 12lb flywheel engineered to provide riders with the precise inertia needed to recreate an outdoor ride feel while training indoors.VIRTUALLY SILENT OPERATIONThe belt motor drivetrain on the KICKR CORE was designed specifically to provide a smooth and virtually silent riding experience.CONTROLLED RESISTANCEWhen connected to your s