As with all their pro series race models, the 4th Generation Pro650 FS 140 sports the new 6/4 Triangular beefy top tube for considerable performance enhancement. Lynskey's new Pro 29 FS-120 frame boasts a massive Helix down tube, Asymmetric chainstays for more drive side clearance and stiffness, horizontally ovalized seatstays and the biggest pivot in the industry for super power transfer and predictable steering response. The suspension kinematics are provided by Luke Beale & David Earle at Sotto Group. Features: Tubing: Fully tuned 3 V/2.5 AL aerospace grade titanium tubeset for stiffness, stability, precise handling, durability and comfort, 6/4 Triangular shaped top tube strongly enhancing performance. Rear Travel: 140mm Headtube Design: Tapered/Integrated Bottom Bracket: 73mm Press Fit 30 Seatpost Diameter: 31.6mm Seat Tube Diameter: (Front Derailleur Clamp Size) 34.9mm Wheel Size: 650b Max Tyre Width: 2.3" Dropouts: Wright-style dropouts for the 12mm oversized rear axle w/ Replaceable alloy Hanger Rear Spacing: 142mm Brake Type: Disc Technology: Lynskey Full Suspension Technology: Lynskey's simple, stiff, effective and very low maintenance single pivot rear suspension system satisfies both sides of a mountain biker's brain. It gratifies the "order" craving left brain as it nimbly carves up singletrack with steady, precise handling, while simultaneously thrilling the creative, thrill-seeking right brain as it gobbles up bumps and brings a smile to your face. The Lynskey FS bikes employ a single pivot with a linkage drive shock that's engineered to deliver the best of both worlds - hardtail-like power to the pedals and crisp steering response AND the ability to absorb all types of terrain keeping rubber down, rider in control and the fun meter up to 11.Pivot location is key to most of this performance and the Lynskey pivot location has been optimized for each platform to virtually eliminate chainstay lengthening, bobbing and anti-squat while maintaining control and suspension balance under heavy braking. Thinking beyond where the pivot and linkage are placed to how those two elements work on the trail, the Lynskey design utilizes the largest, most durable swingarm pivot bearings in the industry. Linkage bearings are simple and durable and both swingarm bearings and linkage bearings are readily available parts that are reasonably priced and easy to swap out.