Surly Big Fat Dummy

Name: Surly Big Fat Dummy
Brand: Surly

2020 UrbanUtilityLong-tail cargo

Last known price: $3,175

Prices shown first for United States
Suspension: Rigid
Wheels: 26″, 29″
Drivetrain: 2 × 11 24–34t / 11–42t
Gear range: 541%
Frame: Steel
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

SM 158–170
SM 158–170
MD 168–179
MD 168–179
LG 176–187
LG 176–187

Components

17 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

Surly 4130 Chromoly steel. Surly 4130 Chromoly steel. Main triangle double-butted. TIG-welded cargo specific engineered for stiffness and durability Not identified

Suspension

1 part

Fork
- Surly

Drivetrain

7 parts

Bottom bracket
- Race Face
Cassette
- SunRace 11–42t
Chain

KMX X11 anti rust Not identified
Crankset
- Race Face Aeffect 34/24t
Front derailleur
- SRAM GX
Rear derailleur
- SRAM GX 2x11 11 speeds
Shifters
- SRAM GX

Brakes

3 parts

Wheels and tires

4 parts

Cockpit and contact points

6 parts

Grips

Velo Single lock-on Not identified
Handlebar
- Salsa
Headset
- Cane Creek Forty
Saddle
- WTB Volt
Seatpost

30.9 2-Bolt 400mm Not identified
Stem

31.8mm clamp 4-bolt Not identified

Sizes and geometry

6 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size MD

Table

Reach 432mm

Stack 597mm

Wheelbase 1563mm

Head angle 69.0°

Seat angle 72.5°

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 6 published sizes

Complete manufacturer geometry by size
Measurement
Frame
Reachmm	408	408	432	432	448	448
Stackmm	578	578	597	597	625	625
Top tube lengthmm	590	590	620	620	645	645
Seat tube lengthmm	356	356	432	432	508	508
Head tube lengthmm	100	100	120	120	150	150
Head tube angle	69°	69°	69°	69°	69°	69°
Seat tube angle	72.5°	72.5°	72.5°	72.5°	72.5°	72.5°
Chainstay lengthmm	875	875	875	875	875	875
Wheelbasemm	1532	1532	1563	1563	1590	1590
Front centermm	661	661	692	692	719	719
Bottom bracket dropmm	55	55	55	55	55	55
Standover heightmm	746	746	792	792	841	841
Fork rakemm	47	47	47	47	47	47
Trailmm	72	84	73	85	72	84
Stack/reach ratio	1.42	1.42	1.38	1.38	1.40	1.40
Suspension and parts
Crank lengthmm	170	170	175	175	175	175
Handlebar widthmm	750	750	800	800	800	800
Stem lengthmm	60	60	70	70	80	80
Stem angle	7°	7°	7°	7°	7°	7°

Not published by the manufacturer: Bottom bracket height, Front travel, Rear travel, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Steel
Fork material: Steel

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 2
Smallest chainring: 24
Largest chainring: 34
Rear sprockets: 11
Smallest sprocket: 11
Largest sprocket: 42
Lowest gear: 16.6 in
Highest gear: 89.6 in

Wheels and brakes

Wheel configuration: Wheel options
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Tire clearance: Maximum tire width: 3″
Travel: Front: Additional specification: Not available: Yes
Rear: Additional specification: Not available: Yes
Wheel material: Aluminum
Wheel size: 26″, 29″

Gearing

Estimated speeds at 80 rpm

Lowest gear: 6.3 km/h
Highest gear: 34.3 km/h

Total gear range 541%

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.