The Series One was their first frame when FITBIKECO started back in 2000 and its their most popular bike to date. For 2026 they’ve upgraded to a CNC machined Integrated headtube and a fully sealed bearing front hub. The S1 frame and fork has been lightened up and offered in 3 top tube sizes with corresponding handlebar and crank sizes.

• SERIES ONE (20.5 TT)
• FRAME: Cro-Mo Front Tri
• GEOMETRY: SERIES ONE
• HEADSET: Integrated w/Gyro Holes
• BB: Mid Sealed
• BARS: 2-Piece 8.7x 29
• FORK: Cro-Mo Steerer, 33mm Offset, Welded Insert
• STEM: FIT Top Load
• SEAT: More Padded Integrated Combo, 200mm Post
• CRANKS: Tubular Cro-Mo 165MM
• SPROCKET: FIT Key 25T
• PEDALS: FIT PC
• FRONT WHEEL: FIT S1W Rim w/Sealed Hub
• REAR WHEEL: FIT S1W Rim w/Sealed 9T Cassette
• TIRES: 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