The internal structures is precise, coupled with 120 sound precisions, ensuring extremely smooth rotation everytimes The bucket shafts systems provide more precise tension, which can better adapt to different spokes tensions, ensuring that the flower drum remain stable and accurate even under extreme conditions Four bearing wheel bring extremely low frictions, with almost none resistance felts during cycling, easy accelerations, and long terms stability It have excellent wear resistance and can bear long terms highly intensity cycling tests The quickly release levers design is strong and easy to operate, allowing for quick disassembly and assembly of wheel with a hand, making daily maintenance