The Series One was FIT's first frame when they started back in 2000, and it’s their most popular bike to date. For 2026, they have upgraded to a CNC-machined Integrated headtube and a fully sealed bearing front hub. The S1 frame and fork have been lightened up and offered in 3 top tube sizes with corresponding handlebar and crank sizes.
Specifications
Frame: Cro-Mo Front Tri
Geometry: SERIES ONE
Headset: Integrated w/Gyro Holes
BB: Mid Sealed
Bars: 2-Piece 8.7”x 29”
Fork: Cro-Mo Steerer, 33mm Offset, Welded Insert
Stem: FIT Top Load
Seat: More Padded Integrated Combo, 200mm Post
Cranks: Tubular Cro-Mo. 20.25TT 160mm
Sprocket: FIT Key 25T
Pedals: FIT PC
Front Wheel: FIT S1W Rim w/Sealed Hub
Rear Wheel: FIT S1W Rim w/Sealed 9T Cassette
Tyres: FIT OEM 2.4”
Brakes: U-Brake w/Low Tension Springs, Two Finger Lever, Linear Cable
Misc: Sealed Front Hub/ Integrated HT New for 2026