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Giant Fathom 1

Giant Fathom 1
  • Color: Knight Shield
Knight Shield
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Riding on new trails. Exploring the backwoods. Catching the scenery. Have fun doing it. That's why Giant built the Fathom 1.

Giant's Fathom 1 was not built as a hardcore race machine. Could you race it? Sure! But it was built for the simple pleasure of off-road riding without overly complicated suspension and a high price tag. For most of us, that's plenty. The fit is a bit more upright, and the handling is stable and predictable; perfect for fun while getting dirty. Giant's ALUXX SL-Grade aluminum makes up the Fathom 1's frame, giving the bike a light feel, while offering rock-solid handling and power delivery. A tapered head tube adds and extra dash of handling precision, especially in tight and twisty singletrack. Internal cable routing gives the Fathom 1 a clean, sleek look. multiple bottle mounts add to the Fathom 1's versatility. An air-adjustable Giant Crest SL RCL suspension fork soaks up technical rock gardens with 130mm of travel. With a 66 degree head tube angle matched with the Crest 34, the Fathom 1 will bring confidence and control to every descent!

When Giant decided to equip the flagship of the Fathom line, they didn't mess around. SRAM's 12-speed SX Eagle shifter and rear NX Eagle derailleur deliver gear changes with lightning speed. An alloy SRAM SX Eagle crankset gets a 30T Direct Mount chainring, providing outstanding power transfer. A SRAM Eagle 11-50T cassette provides a massive gearing range for hilly trails on day-long rides. All this might seem like the component spec on a race bike, but it still makes perfect sense when you just want to enjoy the trails.

Big, meaty tires are what makes the Fathom 1 such a blast. Maxxis supplies the tubeless-ready Ardent Race 27.5x2.6" tires that bite into loose singletrack, gravel and mud with ease. Giant AM 27.5 tubeless alloy wheels anchor those tires with a 30mm interior width, bringing precise handling to twisty trails. Shimano BR-MT420 hydraulic disc brakes help reign in speed in all conditions, rain or shine (or mud). Giant's Contact Switch dropper post helps get the Romero saddle out of the way with a bar-mounted remote lever. An alloy Contact stem and handlebar finishes off the cockpit of this fun-loving machine.


Geometry Chart:
SEAT TUBE LENGTH (mm) 380 430 465 495
SEAT TUBE ANGLE 75.0° 75.0° 75.0° 75.0°
TOP TUBE LENGTH (mm) 592 612 639 662
HEAD TUBE LENGTH (mm) 95 95 105 115
HEAD TUBE ANGLE 66.0° 66.0° 66.0° 66.0°
FORK RAKE (mm) 44 44 44 44
TRAIL (mm) 122 122 122 122
WHEELBASE (mm) 1154 1174 1203 1227
CHAIN STAY LENGTH (mm) 435 435 435 435
BOTTOM BRACKET DROP (mm) 60 60 60 60
STACK (mm) 622 622 631 640
REACH (mm) 425 445 470 490
STAND OVER HEIGHT (mm) 730 745 765 790
HANDLEBAR WIDTH (mm) 780 780 780 780
STEM LENGTH (mm) 40 40 50 50
CRANK LENGTH (mm) 165 170 170 170
WHEEL SIZE 29" 29" 29" 29"
Small 163 cm to 172 cm
Medium 171 cm to 180 cm
Large 179 cm to 188 cm
X-Large 187 cm to 198 cm


Frame ALUXX SL-Grade Aluminum
Fork Giant Crest 34 SL RCL, 130mm, 44mm offset, Boost 15x110
Wheels RIMS Giant AM 27.5, tubeless ready sleeve-joint rim, 30mm inner width
Rims Giant AM 27.5, tubeless ready sleeve-joint rim, 30mm inner width
Hubs alloy, sealed
Spokes stainless steel
Tires Maxxis Ardent Race 27.5x2.6", folding, TR
Bottom Bracket SRAM DUB, press fit
Crankset SRAM SX Eagle, S:165mm, M:170mm, L:170mm, XL:170mm
Chainrings 30T
Shifters SRAM SX Eagle, 1x12
Rear Derailleur SRAM NX Eagle
Cassette/Freewheel SRAM SX Eagle, 11-50T
Chain SRAM SX Eagle
Brakes Shimano BR-MT420/410, hydraulic disc
Rotors Shimano RT-26 rotors [F]180mm, [R]180mm
Brake Levers Shimano BR-MT401, hydraulic
Handlebars Giant Contact alloy TR35
Stem Giant Contact SL 35, alloy S:40mm, M:40mm, L:50mm, XL:50mm
Seatpost Giant Contact Switch dropper w/bar remote, 30.9mm dia.
Saddle Giant Romero
Pedals platform [GC,GT]
Accessories & Extras tubeless prepared, 2.6" max tire size, 32t max chainring size

* Subject to change without notice.