For spinning, large dia rollers, high pressure wider tires
Originally Posted by 11.4
Those charts are notoriously inaccurate. Tire pressure, rider weight, temperature, etc. etc. all contribute hugely. Those numbers can be 30-40% off from what a calibrated SRM will show.
Yes, this is definitely the case since tire deformation is the major influence on power requirements to cycle on rollers. I was reminded just last night when I had to pump my tires back up before I could stay on my rollers for any length of time.
What the chart illustrates is that if the original poster is mainly interested in spinning, he should get large diameter rollers because these have the lowest power requirements. Other things he can do to minimize the power requirements are pump the tires up to the maximum and use relatively wide tires (and I suspect hard/thick tires) since these have a wider contact patch and deform less. Weighing less will also help.
For further details, see Reiser R 2nd, Watt J, Peterson M. Cycling on rollers: influence of tyre pressure and cross section on power requirements. Sports Biomech. 2003 Jul;2(2):237-49. Abstract at LINK