Originally Posted by
bikeme
My experience going from 26 to 29 is completely different than this. The loss of agility was marginal--I did have to take slightly wider lines in tight switchbacks but that became second nature very quickly and I ride even tighter stuff nowadays. As far as speed goes, the 29er was/is faster--I was PR'ing my local segments each ride--I also immediately placed higher in local XC races. Weight-wise , it's lighter as the 26 was a steel bike with heavy tubed WTB Velociraptors and beefy Araya rims and that 29er ( I have a new one) was a carbon frame with light Stans tubeless wheels and XC treaded tires. I got a dropper and that was a game changer for me too.
I currently ride both an old 26" MTB (Turner 5-spot) and a new 29" MTB (Ibis Ripley). With few exceptions, I am substantially faster on my 29" MTB. I tend to feel faster on my old 26" MTB but in the end of the day, the numbers always favor the Ripley. And it is not really that close. On a quick 15 mile loop, I am almost 20 minutes faster on the 29" bike. But it is terrain specific. That is, on another trail - one that is only a 4 mile twisty loop, the bikes are the same (speed wise).
However, I love my 26" bike and won't get rid of it. Even though I am slower, I have tons of fun on the old bike and have no problem riding it anywhere.
The 26" bike is shockingly light as well- with carbon rims, 2.4" tires and a dropper post, the bike is roughly 26 lbs. My 29" bike is 2 lbs heavier - aluminum rims and big 2.6" tires don't help.