Specialized Fatboy 20

Name: Specialized Fatboy 20
Brand: Specialized

2018 MountainFat bike Manufacturer page

Last known price: $770

Prices shown first for United States
Suspension: Rigid
Wheels: 20″
Drivetrain: 1 × 9 28t / 11–36t
Gear range: 327%
Frame: Aluminum
Brakes: Mechanical disc

Sizes

Size guide

The manufacturer did not publish rider heights for these sizes.

Components

9 of 20 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Frame and fork

1 part

Frame

Fully butted Specialized A1 Premium Aluminum, ZeroStack head tube, 100mm-wide threaded bottom bracket, 170mm rear hub spacing Not identified

Suspension

1 part

Fork
- Specialized

Drivetrain

6 parts

Bottom bracket

Square taper, 100x151.5mm, sealed bearings Not identified
Cassette
- SunRace 11–36t
Chain
- KMC X9 9 speeds
Crankset

9-speed, 28T chainring w/ chainguard Not identified
Rear derailleur
- SRAM X4 7 speeds
Shifters
- SRAM

Brakes

1 part

Brakes
- Tektro

Wheels and tires

5 parts

Front hub

Stout 135, loose ball bearings, 10x135 QR, 32h Not identified
Rear hub

Stout 170, loose ball bearings, 9-/10-speed cassette body, 10x170mm QR, 32h Not identified
Rims

20" disc, alloy construction, 68mm internal width, 32h Not identified
Spokes

Stainless, 14g Not identified
Tires

Front: Ground Control Fat, 60 TPI, wire bead, 20x4.0", Rear: Ground Control Fat, 60 TPI, wire bead, 20x4.0" Not identified

Cockpit and contact points

6 parts

Grips
- Specialized
Handlebar
- Specialized
Pedals

Platform Not identified
Saddle
- Specialized
Seatpost

Alloy, single-bolt, 27.2mm Not identified
Stem

Alloy, 7-degree rise, 31.8mm clamp Not identified

Sizes and geometry

1 size Open in the geometry plotter

Complete rider-height ranges are not published for these sizes. You can still explore the geometry below.

Size 20"

Table

Reach 319mm

Stack 464mm

Wheelbase 914mm

Head angle 69.0°

Seat angle 72.0°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 20″ wheel; exact published values are in the table below.

Size Reach Stack

Complete manufacturer geometry table 1 published size

Complete manufacturer geometry by size
Measurement
Reachmm	319
Stackmm	464
Top tube lengthmm	470
Seat tube lengthmm	280
Head tube lengthmm	120
Head tube angle	69°
Seat tube angle	72°
Chainstay lengthmm	390
Wheelbasemm	914
Front centermm	526
Bottom bracket dropmm	25
Bottom bracket heightmm	264
Standover heightmm	583
Fork rakemm	35
Trailmm	75
Stack/reach ratio	1.46

Not published by the manufacturer: Front travel, Rear travel, Crank length, Handlebar width, Stem length, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Aluminum
Fork material: Aluminum

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 28
Largest chainring: 28
Rear sprockets: 9
Smallest sprocket: 11
Largest sprocket: 36
Lowest gear: 15.6 in
Highest gear: 50.9 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Mechanical disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Bottom bracket standard: BSA
Tire width: 4″
Travel: Front: Additional specification: Not available: Yes
Rear: Additional specification: Not available: Yes
Wheel material: Aluminum
Wheel size: 20″

Technical analysis

2 measures

How these figures sit among bicycles of the same class and model year. Context, not a ranking.

Lowest gear

15.6 gear inches

This value is below the central range for this class.

Cohort: Mountain / Fat bike Model year: 2018
Sample: 60 bicycles with this information
Coverage: 98.3% of the class

Highest gear

50.9 gear inches

This value is below the central range for this class.

Cohort: Mountain / Fat bike Model year: 2018
Sample: 60 bicycles with this information
Coverage: 98.3% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 6.0 km/h
Highest gear: 19.5 km/h

Total gear range 327%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 15.6–50.9 gear inches
Class reference (p10–p90): 14.9–85.1 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Mountain / Fat bike Model year: 2018
Lowest gear: 60 bicycles with this information, 98.3% of the class
Highest gear: 60 bicycles with this information, 98.3% of the class

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2018 builds

Differences across 2018 builds
Specification	This bicycle Specialized Fatboy 20	Specialized Fatboy	Specialized Fatboy 24	Specialized Fatboy Comp Carbon	Specialized Fatboy Expert Carbon	Specialized Fatboy SE
Frame
Frame material	Aluminum	Aluminum	Aluminum	Carbon	Carbon	Aluminum
Fork material	Aluminum	Carbon	Aluminum	Carbon	Carbon	Aluminum
Drivetrain
Smallest chainring	28	30	28	30	28	28
Largest chainring	28	30	28	30	28	28
Rear sprockets	9	11	9	12	11	10
Smallest sprocket	11	11	11	10	10	11
Largest sprocket	36	42	36	50	42	42
Lowest gear	15.6 in	18.6 in	18.7 in	15.6 in	17.3 in	17.3 in
Highest gear	50.9 in	70.9 in	61.1 in	78.0 in	72.8 in	66.2 in
Brakes
Brake type	Mechanical disc	Hydraulic disc	Mechanical disc	Hydraulic disc	Hydraulic disc	Mechanical disc
Other specifications
Bottom bracket standard	BSA	BSA	BSA	PF30	PF30	PF30
Tire width	4″	4.6″	4″	4″	4″	4.6″
Wheel material	Aluminum	Aluminum	Aluminum	Aluminum	Carbon	Aluminum
Wheel size	20″	26″	24″	26″	26″	26″