The Riff is Soma's hardtail frame for 27.5"/650b wheels. Geometry is ideal for single-track, flowy trails, and bikepacking. Tough IRD Broski Sliding Dropouts allow you to go single-speed or geared or even run hub gears. While the industry is telling everyone to get "Boost", the Riff lets you run an OLD 142mm thru-axle (or even 135mm QR with a different insert). Another retro feature: you can use a front derailleur if you want.