Kickr Core features a 12lb flywheel and advanced algorithms engineered to provide riders with the precise inertia needed to recreate an outdoor ride feel . When connected to your smartphone tablet computer or GPS bike computer KICKR CORE smart bike trainer automatically controls your resistance based on the software or route. Seamlessly connects to the hardware devices and software platforms that make up the Wahoo indoor cycling ecosystem. Robust steel construction ensures the KICKR stays in place while you crank out the watts and stands up to years of heavy use. Compatible with 8 9 10 11 and 12 speed cassettes plus the Zwift Click and Cog. Connectivity: ANT+ ANT+ FE-C and up to three Bluetooth Connections. Maximum Power Output: 1800 Watts. Maximum Simulated Grade: 16%