Answer
Reducing weight in the wheels makes it easier on the cyclist than reducing the same amount in the frame.
Work Step by Step
If we reduce the weight of the frame, then the bike's mass is reduced so it will be easier to increase the translational kinetic energy of the bike.
However, if we reduce the weight of the wheels, then the mass of the wheels is reduced so it will be easier to increase the translational kinetic energy of the bike and the rotational kinetic energy of the wheels. That is, the mass in the wheels is a factor in both translational kinetic energy of the bike and rotational kinetic energy of the wheels.
Therefore, reducing weight in the wheels makes it easier on the cyclist than reducing the same amount in the frame.
