27.5″ aluminum frame. 24 gears (3 chain rings in the front, 8 in the back). Very reliable bicycle. No issues. Here is a link to some more technical details: https://99spokes.com/bikes/specialized/2017/roll-elite This bike ignited my love for bicycling. It is very comfortable to ride and the saddle is the best! I'm selling it because I switched to a gravel bike. Pick-up only. Thetis Heights.