I rode a small wheeled bike last night. For the first time in, oh, maybe a year or more, I swapped out bikes so that a trained circus bear could ride the Giant XTC 29er 1 and I rode his 26" wheeled Kona hardtail. I understand this wheel size is looking to gain traction (literally) in the world of mtn biking and I have a few thoughts on this, since many 29er riders may be tempted to embrace this technology.
After riding half of the local loop on this lesser hooped bike, I can predict a few things:
1) Riders coming from the gold standard of 29" wheels will immediately feel more agile and moto. Manuals and wheelies will be easier, surprisingly so.
2) The first few pedal strokes will feel zippy and quick, leading you to think you are faster all of a sudden.
3) Then, you will notice that you are working harder to keep those zippy feeling wheels spinning along since they are just as easy to un-zip as to zip.
4) Sand, rocks, ruts...all will conspire to grab at those tiny wheels and reduce your momentum. The agility that allows for manuals and wheelies also allows for darty, nervous, and pin-ball like trail performance. Not a good trade off unless you manual all the way down a trail. I don't.
5) The trail will seem to have grown bumpier and less flowy. You will stop and check the pressure of the diminutive tires, thinking they are over inflated. Nope.
In the end, this new attempt at a mountain bike wheel standard may have some advantages for the acrobatic or very aggressive rider, especially if the wheels are off the ground a lot. Most riders actually go down a trail or up a hill with their tires touching the ground and if so, the 29er wheel will stay the preferred standard for this type of reality based riding.
My predictions, anyway.