The Series One was our first frame when we started FIT back in 2000 & its our most popular bike to date. For 2026 weve upgraded to a CNC machined Integrated headtube & a fully sealed bearing front hub. The S1 frame & fork has been lightened up & offered in 3 top tube sizes w/ corresponding handlebar & crank sizes.

Specs:

20.25″, 20.5″ & 20.75 Top Tube

Bars: 2-Piece 9 X 29

Cranks: 160mm, 165mm or 170mm

FRAME: Cro-Mo Front Triangle

GEOMETRY: Series One

HEADSET: Integrated w/Gyro Holes

BB: Sealed Mid

BARS: 2-Piece 9 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 170mm

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

MISC: Sealed Front Hub/ Integrated HT New for 2026