Originally Posted by
Dave Mayer
Wheels are one of the biggest factors in bike performance. Bearing drag is absolutely negligible, but wind resistance and rotational inertia are very important. Rotational inertia is largely a function of rim weight, and this determines how much force is required to spin the wheels up (accelerate) or slow them down.
Rotational inertia variations of the magnitude seen between bicycle wheels that'd be swapped for each other is effectively irrelevant.
Weight at the tire surface does count double for acceleration purposes although with the low mass involved that still doesn't matter.
Consider a 145 pound cyclist atop a bike approaching the UCI 15 pound minimum with total mass of about 70kg and ignore the rotational inertia of his existing wheels. The effect is proportionally less for larger people.
Making a 1% change in his effort to accelerate would take more than a 350g change in wheel + tire weight at the road surface increasing to 700g as you approach the hub centers.
A Velocity girder single walled rim weighs 560g versus 430g for an Aerohead which is typical for road rims which hold up to use which nets 230g for the pair.
Riding a lightweight set of wheels in stop & go traffic is a revelation, as is riding deep-dish aero wheels at sustained high speeds.
Placebo effect aside it doesn't matter.