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Old July 16th 18, 01:09 AM posted to rec.bicycles.tech
Oculus Lights[_2_]
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Default 29er "pedals easier"

On Sunday, July 15, 2018 at 10:00:30 AM UTC-7, wrote:
I have a friend who just bought a new 29"-wheel Motobecane MTB and swears that, due to the larger-diameter wheels, it "pedals easier" than his old 26"-wheel MTB did.

Have you ever heard anyone say this before? I have.

Since the contention does not seem correct to me, I was just curious about how you gentlemen would respond to it?


Misusing the laws of physics to mislead the reader into a false conclusion.
A heavier rotating mass, or the same mass at a longer radius,
will need more energy to bring the linear velocity that the circumference is rotating at up to the same velocity.
That greater amount of momentum will require greater opposing force to slow it down. That's how the claim that a larger tire can roll easier is true..
But do we want a tire that rolls "easier" or that can be brought up to a desired rolling speed, easier?
This also leaves out aerodynamic drag. There's more drag on a taller tire and wheel of the same width. So you also have to overcome that drag. That drag on the tire and wheel is constant regardless of the bumps and surface resistance against the tire tread.
The aero part is easily seen by going back to when TT bikes were using smaller diameter front wheels till UCI banned that.
My MTB is still the same 26" rim brake wheels that its had since new in 2000. If it can't roll over the bumps and rocks and ruts and slop I want to roll over, then its the rider, and not the tire diameter that's the problem.
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