I feel slower on my steel framed bike than on my carbon bike on the same commute route to work where I climb up into the mountains. In fact, I am slower, just over 2 mpg average speed slower. In fairness, the carbon bike is lighter, not just because of its frame, but lighter components and narrower tires, etc, all those things folks will tell you make no difference.
Oh ya, I was sure my workout on Sunday was my fastest I’ve ever done that route, I was flying…….I was 1mph off my average over the 35 mile run, I was not even close to a
PR, but it felt fast.