I put a 27.5x2.8 on the back of my 2015 Santa Cruz Superlight 29er and never went back. This is a cross country frame with only 100mm shock. The 27.5 plus on the back not only slackened the bike but feels like it added suspension in the back. Paired with a 120mm fork it feels great. BB drop has not been an issue and I feel like I still have better clearance on this bike than my 2014 trek remedy but I haven't measured it. When aimed downward I am amazed at how capable this bike is for such short...