Originally Posted by
bradtx
Slaninar, The last paragraph of dabac's post sums it up nicely. Wheel and tire weight matter the most as there are two factors involved, static weight and rotational weight. It simply takes more energy to spool up a heavier tire and wheel combo and more energy to slow them down. A heavier tire and wheelset can be a benefit on an uninterrupted (no traffic signals) ride on fairly flat terrain as there's some flywheel effect.
The impact of rotating mass doubles as you move from the center of the axle (where it's not rotating at all) out to the tire surface although it's not enough to be significant for reasonable variations in component weights.
There's about a 150g difference between a heavy rim (DT585 or Velocity Deep V) and a light but durable rim (Kinlin XR-270/300, Mavic Open Pro although some would argue that those aren't durable enough). There's another 180g separating a heavy tire (32mm wire bead Gatorskin) from a light one (23mm GP4000S). That's 660g for a pair of wheels.
As an upper bound you can treat all that mass as being where the rubber meets the road. With a 75kg rider + 9kg bike combination having that 660g as rotating mass instead of elsewhere on the bike means the rider needs to provide less than 0.8% more kinetic energy to reach a given speed. With an extra 660g in the rims and tires bringing the bike weight to 9.66 kg the rider needs 1.6% more kinetic energy to reach a given speed.
That's just within the accuracy limit of bicycle power meters and the effect on time to accelerate (especially in a sprint) is a lot less because most of your power is going into overcoming aerodynamic drag.
Lighter tires can be easier to accelerate but the physical effect comes from the reduced rolling resistance that goes with having a thinner, more flexible carcass to deform as you roll down the road. The psychological impact from what things sound like changes peoples' perception too.