John K.wrote a review of Niner Air 9 RDO Mountain Bike Frame - 2019 on August 1, 2018
Familiarity: I've put it through the wringer
Love it, great climbing machine and rides much softer than my Aluminum frame AIR 9. Have over 3,000 miles on this frame since I bought it and had it built up with some components from another bike and some new. Be sure you have a shop that knows about building Niner frames out since frame is best with 1X or 2X. I made the mistake of bringing over my existing 3X drive train and had some chain suck issues and ultimately had to do some minor repairs to the frame because of it. The pricing on this site beats NINER warranty pricing by a wide margin. I also purchased XT brakes and Industry Nine wheel set which gave me a tremendous upgrade to my WTB gear. One other warning which would have been handy to know is that Aluminum seat posts oxidize and freeze fast to the carbon frame which I am dealing with now. That is something that someone along the way should have mentioned.