The 26er
Pros: Excellent on steep and stepped climbs. Easy to accelerate out of momentum sapping situations. Braking was strongest, especially at the bottom of steep descents. By far the most responsive to pumping the trail. A light-feeling that encourages the rider to hop over or around obstacles. Cons: Descending is intimi dating, especially after spending time on the other two MTB wheel sizes. This bike requires more rider input and a bigger commitment. Rider position has a bigger effect on how the bike handles and responds. While a rider can “roll” a techie section on the larger carbn fiber wheels, the 26er rider has to attack and maintain enough speed to stay on top of the ruts, rocks and flat-edged bumps. The rider has to work on looking ahead, as the 26er places the rider lower over the front.

The 27.5er(650b mountain bike)
Pros: it has a nimble feel that is way closer to the 26er than the 29er, but it doesn’t require the rider to work as hard. Your body position always feels neutral. You can pump the 27.5er along the trail, and when the trail heads downward, it allows the rider to remain relaxed. You don’t need to attack rough sections. These wheels do a good job of staying on top of the rough stuff, and the front end goes where you want it to go. Cons: We couldn’t come up with a ride negative. It doesn’t steer as fast as a 26er, but we never found a trail so tight that this made a difference. It didn’t roll over the rough sections as smoothly as the 29er, but again, it wasn’t a big enough difference to put the 27.5 rider off the wheel of the 29er.

The 29er
Pros: The big china carbon wheelsets are great for descending. They smooth out nasty trail that would have you puckered on the 26er. The added confidence inspires you to remain more relaxed as the wheels float over rocky terrain. The big hoops offer the best traction of the bunch, both in corners and on loose climbs. This bike requires the least amount of body English to stay hooked up (going up or down). Crewers noted they remained seated longer in the 29er. Once up to speed, the bike holds momentum well—and holding momentum is what the 29er is all about. Cons: Getting up to cruising speed takes more effort. Steep climbs or regaining speed following a momentum- zapping misstep is noticeably tougher. The only plus here is out-of-the-carbon-saddle efforts work great because the rear tire maintains traction. The large alloy wheels don’t respond as well to pumping the trail, and lofting the wheel requires more effort. This bike doesn’t have that lively squirt of acceleration you feel on both the 26er and 27.5er when working the backside of a whoop. The larger rotor up front wasn’t enough to give this bike the braking power we wanted.