Specialized Fatboy SL

2015 MountainFat bike Manufacturer page

Suspension: Rigid
Wheels: 26″
Drivetrain: 1 × 11 30t / 10–42t
Gear range: 420%
Frame: Aluminum
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

SM 158–171
MD 168–180
LG 178–189
XL 186–199

Components

16 of 22 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

Specialized M4 Premium Aluminum, fully butted w/ smooth welds, tapered headtube, post-mount disc dropouts, 190mm rear hub spacing, replaceable alloy derailleur hanger Not identified

Suspension

1 part

Fork
- Specialized

Drivetrain

6 parts

Bottom bracket

PF30, 100mm, press-fit Not identified
Cassette
- SRAM
Chain
- KMC
Crankset
- Race Face Next SL 30t
Rear derailleur
- SRAM XX1
Shifters
- SRAM XX1 Trigger 11 speeds

Brakes

2 parts

Wheels and tires

5 parts

Front hub
- Specialized
Rear hub
- Specialized
Rims
- HED
Spokes

Stainless, butted, 2.0/1.8/2.0mm, black Not identified
Tires
- Specialized

Cockpit and contact points

7 parts

Grips
- Specialized
Handlebar
- Specialized
Headset

1-1/8"" upper, 1-1/2"" lower, Campy style, integrated sealed cartridge bearings Not identified
Pedals

Alloy, 1 pc. body, 9/16"", w/ reflectors Not identified
Saddle

Body Geometry Phenom Expert, hollow Ti rails, 143mm Not identified
Seatpost
- S-Works
Stem
- Specialized

Sizes and geometry

4 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size MD

Table

Reach 420mm

Stack 600mm

Wheelbase 1105mm

Head angle 70.5°

Seat angle 73.0°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 26″ wheel; exact published values are in the table below.

Size Reported by the manufacturer

Complete manufacturer geometry table 4 published sizes

Complete manufacturer geometry by size
Measurement
Frame
Reachmm	395	420	437	458
Stackmm	590	600	615	629
Top tube lengthmm	576	603	625	650
Seat tube lengthmm	394	445	483	533
Head tube lengthmm	110	120	135	150
Head tube angle	70.5°	70.5°	70.5°	70.5°
Seat tube angle	73°	73°	73°	73°
Chainstay lengthmm	455	455	455	455
Wheelbasemm	1083	1105	1128	1154
Front centermm	635	657	680	706
Bottom bracket dropmm	60	60	60	60
Bottom bracket heightmm	315	315	315	315
Standover heightmm	757	793	820	849
Fork rakemm	46	40	41	41
Trailmm	73	79	78	78
Stack/reach ratio	1.49	1.43	1.41	1.37
Suspension and parts
Crank lengthmm	170	175	175	175
Handlebar widthmm	750	750	750	750
Stem lengthmm	60	60	70	70

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

Specifications

Frame and fork

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

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 30
Largest chainring: 30
Rear sprockets: 11
Smallest sprocket: 10
Largest sprocket: 42
Lowest gear: 18.6 in
Highest gear: 78.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Bottom bracket standard: PF30
Tire width: 4.6″
Wheel material: Carbon
Wheel size: 26″

Gearing

Estimated speeds at 80 rpm

Lowest gear: 7.1 km/h
Highest gear: 29.9 km/h

Total gear range 420%

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: 18.6–78.0 gear inches

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 2015 builds

Differences across 2015 builds
Specification	This bicycle Specialized Fatboy SL	Specialized Fatboy	Specialized Fatboy Expert	Specialized Fatboy Pro
Frame
Fork material	Carbon	Carbon	Carbon	Aluminum
Suspension
Suspension configuration	Rigid	Rigid	Rigid	Hardtail
Drivetrain
Front chainrings	1	2	2	1
Smallest chainring	30	Not informed	22	30
Largest chainring	30	Not informed	36	30
Rear sprockets	11	10	10	11
Smallest sprocket	10	11	11	11
Largest sprocket	42	36	36	42
Lowest gear	18.6 in	Not informed	15.9 in	18.6 in
Highest gear	78.0 in	Not informed	85.1 in	70.9 in
Cockpit
Seatpost	Rigid seatpost	Rigid seatpost	Rigid seatpost	Dropper seatpost
Other specifications
Suspension	Rigid	Rigid	Rigid	Hardtail
Travel	Configuration: Rigid	Configuration: Rigid	Configuration: Rigid	Configuration: HardtailFront: Additional specification: Not available: No
Wheel material	Carbon	Aluminum	Aluminum	Aluminum
Fork spring	Not informed	Not informed	Not informed	Air