Quiver

2015 Specialized Fatboy Pro vs 2015 Trek Farley

The Trek Farley size closest to your M is the M. Compare the M instead

What changes on the Trek Farley

Compared with the Specialized Fatboy Pro in M, the Trek Farley in XL places the top of the head tube 13 mm higher and 35 mm further forward, relative to the bottom bracket. Its wheelbase is 36 mm longer, which can contribute to stability at speed.

Frame stack
+13 mm
Higher front end
Frame reach
+35 mm
Longer frame reach
Wheelbase
+36 mm
Longer: steadier at speed
Head angle
−0.5°
Slacker: calmer steering
Chainstays
−15 mm
Shorter: livelier

The two frames

2015 Specialized Fatboy Pro (M)The Specialized Fatboy Pro frame drawn to scale.J 1105

Only the Specialized Fatboy Pro is drawn. The Trek Farley numbers we have for size XL are missing the seat angle.

Geometry side by side

MeasurementSpecialized Fatboy Pro MTrek Farley XLDifference
Reach420mm455+35 mm
Stack600mm613+13 mm
Head tube angle70.5°70.0°−0.5°
Seat tube angle73°not listed
Effective top tube603mm643+40 mm
Chainstay length455mm440−15 mm
Wheelbase1105mm1141+36 mm
BB drop60mm55−5 mm
BB height315mm313−2 mm
Standover793mm832+39 mm
Seat tube length445mm521+76 mm
Head tube length120mm120±0 mm

Differences are the Trek Farley minus the Specialized Fatboy Pro. Full charts: 2015 Specialized Fatboy Pro, 2015 Trek Farley.

Where each sits in its class

Specialized Fatboy ProTrek Farley

AggressivePositionUpright
CalmSteeringQuick
PlayfulBalancePlanted

Each bike is ranked against the other fat bikes on Quiver, on frame geometry alone. Not your hand position or ride feel.

What each ships with

The stock build of each bike's first listed trim. Parts that match are dimmed.

PartSpecialized Fatboy ProProTrek Farley6
ForkRockShox Bluto RLnot listed
ShifterSRAM X01Shimano Deore
DerailleurSRAM X01SRAM X-5, Shimano Deore XT
CassetteSRAM X1Shimano HG50
ChainKMC X11LKMC X10
CranksetRace Face Next SLnot listed
PedalsSpecialized Benniesnot listed
TireSpecialized Ground Control FatBontrager Hodag
HubSpecialized Hi Lonot listed
RimSpecialized Fatboy SLSun Ringlé Mulefüt
BrakeShimano XTAvid DB 1
GripsSpecialized Contournot listed
Dropper postSpecialized Command Post BlackLitenot listed
Framenot listedTrek Alpha Platinum
Headsetnot listedFSA IS2
Saddlenot listedBontrager Evoke 2

Know what is on every bike.

Add your bike to Quiver. Keep its parts, setup, and service history together, then share your build.

Explore the app
A Transition Relay build sheet: frame, fork, shock and drivetrainThe Relay’s ride photo galleryThe Relay’s ride spectrum and 2D frame geometryThe garage: five bikes and 99 recorded partsA Specialized Tarmac SL8 road build sheet