Niner SIR 9 4-Star X01 Eagle 27.5+

Take charge of your ride with this Reynolds 853 Steel frame designed around Niner's [R]evolution trail geometry, which begs the rider to push their limits. Ride it hard. Ride it fast. After all, it's made from a truly time-tested material that's been air hardened and heat treated. The efficient yet compliant ride quality of the SIR 9 harkens back to a simpler time. A time without linkages and complicated shock settings. A time where all the energy you put into the pedals moves you forward.

The SIR 9 features a redesigned bottom bracket and chainstay junction—keeping ride quality in mind as well as tire clearance, Niner went to great lengths to design this crucial element. The PF30 Bottom Bracket allows you to run a standard press fit bottom bracket or, if simplicity is your thing, throw in an eccentric bottom bracket and run it singlespeed. Additionally, it has the ability to run 1x, 2x, or 3x systems for a drivetrain to suit every rider and trail. A hidden plate inside the chainstay yoke stiffens and strengthens in order to improve power transfer. For bikepacking aficionados, this frame is extremely versatile. It offers a whopping 18 mounting points, allowing you to run racks and fenders, a top tube Bento box, 3 water bottles, and more, so you can easily pack it in and pack it out. The frame accepts up to a 120mm fork for truly getting rad, and is compatible with 29-inch or 27.5-inch plus tires.

- SRAM X01 Eagle drivetrain
- SRAM Guide RSC brakes
- Race Face Next R carbon bars