[dnhz]

I don't believe it. When I had a cheapo mountain bike, I could hear the tires on the road, especially at higher speeds. With my current road bike, the tires are a lot quieter. That noise translates into lost energy, including lost energy that can't be heard. Sure the bikes differ a lot, but the difference in rolling resistance is stark to me. The road bike also can roll for a lot longer a distance.

[msandford]

It sounds like you haven't read even a paragraph or two. They're talking about road slicks vs road slicks, not mtb tires vs road tires.

[dnhz]

I read it. But I didn't think there would be a difference between knobby and non-knobby tires compared to the changing width.

[discreteevent]

Mountain bike has knobbly tread. This article is taking about wide smooth tires.