Evolve'd
Let me get this off my chest... I don't buy into the hype of the 29er wheels. For one thing, I'm not all that tall--I'm 5'8" on a good day. If I stretch.
For another, they move the largest chunk of rotational mass further away from the axis of rotation. Look at this equation for the rotational inertia of a hoop:'I' is the rotational inertia, 'M' is the mass of the hoop--I'm simplifying here, you understand--and 'R' is the radius or distance that M sits from the axis of rotation. Now, if we are comparing a 29" wheel to a 26" wheel, we can ignore the contribution of the hub--it's the same for both wheels--and mostly ignore the spokes--they do contribute, but very little. Let's also assume that the tires and tubes and rims weigh the same. They don't, the 29er Rim/Tube/Tire combo weighs more, but it helps simplify things here a little.
Now, we've reduced the equation to just looking at the contribution of 'R'. If a 26" wheel has an Effective Radius of 13.25" and a 29er wheel has an Effective Radius of 14.25", the smaller wheel will only have approximately 85% of the rotational inertia of the larger wheel.
"That's great" you say, but what does it all mean? I means that you will expend less energy--roughly 15% less--to spin up the smaller wheel. A different equation shows that turning the smaller wheel requires less energy, as well.
This was a very long way of saying that with my short legs, and the slower feeling wheels, I've never been interested in riding a 29er for any length of time. On shorter rides I've always felt like I was perched way up high on top of the bike, rather sitting in the bike, if you catch my meaning.
Then I got a call from Tony Ellsworth. He's roughly my size and rides an Evolve--their version of a 29er. He gave me my choice of reviewing an Epiphany--5.25" of travel, 26" wheels--or an Evolve--4" of travel, 29" wheels. I chose the Evolve.I figured that he can ride any bike he wants--it's his company after all--and he rides a 29er. And, if I was going to bash 29" wheels, then I better use them on my trails, the same ones that I ride my own mountain bike.
I received the bike yesterday and, after putting it together, took it out last night on a ride that had quite a bit of up and down. In short, I had a blast. Now, riding a new bike is always fun, so after I log more miles I'll share some more thoughts about it. But, needless to say, I might, might, be... not wrong so much, but... well, missing something that doesn't fit into the math.
We'll see. And, hey, if I'm wrong, I'll admit to it publicly. Total transparency here, folks.

