United States


Big Fat Dummy

Big Fat Dummy line art

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Complete & Frame

Surly 4130 CroMoly steel. Main triangle double-butted. TIG-welded cargo specific engineered for stiffness and durability

Rear Dropouts
Vertical, 197 x 12mm spaced, Surly thru axle included

Brake Compatibility
51mm disc mounts

Upper and lower triple bottlecage mounts on downtube, Double waterbottle bosses on seatube (not included on the small frame size), Surly Trip Guides for continuous brake/shift housing or brake hydraulic line (toptube and seatstay routing), Internal dropper post routing

Seatpost diameter

Seatpost clamp diameter
33.1mm (Surly stainless included)

Headset/Steerer Tube
ZS44/28.6 upper, EC44/30 lower

Front Derailleur Clamp Diameter
34.9mm, direct mount included

Bottom bracket shell
100mm wide, threaded English (1.37˝ x 24t)

Chainring Clearance
No frame limitations. Use whatever you want

Tire Clearance
26 x 5.25˝, individual tire and rim combos may require different drivetrain choices to avoid chain/tire rub

Fork Compatibility
Surly Wednesday, Tapered straight blade 4130 CroMoly. 468mm axle to crown, 47mm offset. 51mm I.S. front standard disc mount, 150mm x 15mm thru-axle dropouts (axle included), 100mm suspension fork compatible

Thru Axle
HU0139 Surly 15x150 Front Thru Axle
HU0136 Surly 12x197 Rear Thru Axle

Cromwell Green