The Kreitler Flywheel adds rotating mass to your rollers. Running off a belt connected to the rear drum, the Flywheel increases resistance and creates a more natural road-like feel. With increased inertia it takes longer to get up to speed and once there creates more than enough resistance to do high power efforts. You still get the free moving feel of rollers and the need to balance and stay upright while working hard.
A winter spent doing Sweet Spot, Threshold and VO2 Max efforts on the Kreitler Flywheel and rollers will improve your core strength, pedaling action and souplesse way more than the same efforts on a turbo trainer.
The wattage chart below shows how much resistance a flywheel adds to the different sized Kreitler Rollers.
The Kreitler Flywheel works with the Standard Frame only, not the Kompact Frame. Left Side and Right Side versions are available and there is no difference in performance whether you choose the Left or Right Flywheel.