Cycleops engineers designed the fluid 2 to capture real road feel through the use of a 275 lb individually precisionbalanced flywheel for more momentum and stability of your rear wheel they also adjusted fluid levels for better resistance and improved the position of sealedcartridge bearings for better inertia and an ultra quiet ride that ensures increased wattage as you increase your speed and just like riding outside simply shift gears to increase or decrease resistance when you spin yo