The flywheel is positioned at the front of the bike where the front wheel of a bicycle would be. Although it’s disc-shaped, it’s not there to look like a wheel and simulate a road bike. Rather, it serves the critical function to store rotational energy to ensure your indoor bike runs smoothly. Not only does this make for an enjoyable experience, but it prevents damage to the bike and injury to the rider. As you shop for a new exercise bike, analyzing the flywheel is very important. As it limits rotation, it simultaneously works to control both inertia and resistance.