Good point Tom... I don't know which one was correct, but I have a way to check it...the bike path along Lake Okeechobee has mile markers painted on the asphalt. I can do a ten mile run and see how far off I am with each bike and then make adjustments. I know the amount of effort that I put out on the Giro is MUCH higher to keep the speed up and will be ordering some 100psi tires tonight after work.
Thanks for the math lesson!
Tractor Tom in Okeechobee, FL