I know nothing about engineering.
I feel like I can expend the same or even less effort riding a mountain amd a road bike (if going slowly) but feeling is not reliable, so I hope to get some insight on this matter.
Let's assume the mountain bike has a hard fork, hard tail, really thin tires. At same price as the road bike. The two bikes are going for the same distance on a smooth road, with no wind. I don't know if climbing and decending make much difference.
What I guess is, if I am going slow, so the aerodynamics of a road bike will not make much difference, won't I using almost same effort to cover the same distance?
Gear ratios affect fuel consumption, so can I manage my gear ratio and speed to save total work I expend? Will a mountain bike will require less work to cover the same distance?
When riding in the city where you have to frequently stop and start, does a road bike need more effort than mountain bike since it has higher ratio gearing?
Is there some way to test this without a lab environment? I can't find a way to measure how much work I'm doing, and total work I expended.
Please feel free to educate me, I just want to know more.
Where I got this weird idea was from my wife:
She got a hard tail hard fork DIY XC bike, with carbon frame and fork. it was decently light, at about 10KG, slick tire with high pressure and very narrow. It cost bit more than US$1600.
But, she only rides it if we are going out town. She commutes with a US$45 lady bike, she said it was not much difference riding this bike, if under 4km.
I tried her lady bike, it was pretty easy riding short distance in the city, but very hard at longer distance on account of riding posture, and very small bike -- riding slowly of course.