This is arguably the most hotly debated subject in mountain biking these days, and we have plenty of customers asking us if a 29er or 26 inch wheeled mountain bike is better for their needs on an almost daily basis, so we figured we'd take a stab at the answer here. Truth be told there's no info below that hasn't already been shared on umpteen other websites so we're not really adding anything new to the dialogue, but if you want our opinion here it is...
First, we'll sit the fence. Neither a 29er or a 26 inch mountain bike is the holy grail of cycling. Furthermore, so long as the bike is safe and fits you we're happy to see you riding whatever you're riding. With that said, here are some advantages of both wheel types:
26 inch:
(a) They're lighter, everything else being equal. 29er wheels have improved greatly in the weight department in the last few years, but in most instances and especially in the lower to mid range a 26 inch wheel (with the accompanying tire) is going to be lighter because it's smaller. Pretty simple really. And remember, that's rotating mass, so it makes even more difference to the ride than stationary mass on, say, your frame. However, higher rotating mass may actually be an advantage too (more about that further down).
(b) They're easier to turn. If you're bombing through really tight technical stuff most of the time a 26 inch wheel will serve you better because the smaller diameter changes direction more quickly.
(c) They fit smaller frames. If you're not particularly tall it can be difficult to build a frame around a larger wheel size using optimal geometry. 26 inch wheels fit into good frame geometry for a bike built for anyone at least 5 feet tall, give or take.
29ers:
(a) The greater mass of larger wheels/tires can arguably be an advantage if you're riding over undulating terrain with occasional short dips and climbs because the higher rotating mass can actually carry you through a bit of the climb. Or at least that's the theory. We haven't actually tried to test it in a controlled setting, and the theory does have its detractors.
(b) The larger diameter rolls more easily over small roots and rocks, and more easily bridges the gap of small dips and potholes.
(c) The higher volume tires offer more contact patch thus providing more grip, and they also offer more 'suspension' when run at low pressure.
So what's right for you? There isn't usually one clear cut answer because most of us ride in a variety of conditions. Truthfully we'd consider it optimal if we could start riding the sweepy sections of the Bur Oak trails in Bird's Hill Park on a 29er and then have someone hand us a 26 inch wheeled bike as we approached the tight forrest bits.
What we will say is that 29ers, in most cases, make a lot of sense for our hard tail customers who want a bit more cushion and a bit more help over rocks and roots without adopting a dual suspension bike. In our opinion there is a lot of value in a 29er hard tail if you're looking for something to take the edge off of a 26 inch wheeled hard tail bike but don't want to lay out the relatively big bucks for a dulie. That's certainly not the only reason to consider a 29er, but it's one.
Ultimately though you need to swing your leg over both and see what works best for you. We have plenty of 26 inch and 29er bikes in stock so come and check out both anytime so you can decide for yourself.