I have several bikes. I noticed that the rear wheels on my hybrid and mtb turns slower than on both of my road bikes. I believe that some bikes have some type of internal resistance that must be overcome in order for the initial rotation to begin. Once begun, it will continue to rotate, but will come to a complete stop much sooner than wheels with less internal resistance. It takes more energy to overcome this internal resistance.
My road bikes are so much easier and fun to ride!