Big Dummy
Big Dummy is a long-tail cargo bike, which means that not only can you haul a serious amount of cargo, different accessories can be added to your Big Dummy frame and deck depending on what you want to carry. Being a dedicated single-piece frame, instead of an add-on to an existing bike, it’s stiffer and resistant to torsional flex, which provides a better ride and longer lasting frame than long-tail add-ons.
Like all our frames, it’s made of our size specific, 4130 CroMoly steel – a tube set engineered for cargo that sports lots of little touches that you’ve come to love in a Surly like clearance for big tires and the use of common component sizes. Figure on being
able to carry about 200 pounds (90kg) of cargo. The load weight, and how it’s loaded, will affect the handling somewhat. Also, plan on using gears, especially as cargo weight increases. This may seem obvious, but as you get comfy with it, you will use your full range of gears as never before.
If you intend to carry a passenger on your Big Dummy, Surly requires use of our Dummy Rail Collars. These provide a secondary retention system for the rack, as well as stiffen the rack system. These are included with MY18 Big Dummy bikes and frames, as well as available AM for older Big Dummy bikes and frames [compatible with all generations of Big Dummy bikes/frames]. In addition, a stoker handlebar set up, found on tandem bicycles, is recommended as well. Make sure to check with seat post manufacturer for stoker handlebar compatibility.
If you are planning to carry a child on your Big Dummy, Surly recommends the use of a child seat. We’ve tested the Maxxi Yepp seat. They make an adaptor that that allows their seat to mount onto our deck. It works well with the Big Dummy. At this time other child seats are not recommended and will void your warranty. We are testing other options. For the most up to date compatibility/options, check
here.
Note: keep in mind Big Dummy weight limits when carrying a passenger.
FRAME COMPATIBILITY
- Tubing: Surly 4130 CroMoly steel. Main triangle double-butted. TIG-welded cargo specific engineered for stiffness and durability
- Rear Dropouts: Vertical, 135mm spaced with fender eyelets; Rohloff compliant
- Brake compatibility: 51mm disc mounts and removable cantilever pivots
- Braze-ons: Quad water bottle mounts, Surly Trip Guides for continuous brake/shift housing or brake hydraulic line (toptube and seatstay routing), fender eyelets
- Seatpost diameter: 27.2mm
- Seatpost clamp diameter: 30.0mm
- Headset/Steerer Tube: 1-1/8˝ threadless
- Front derailleur clamp diameter: 28.6mm (1-1/8˝) clamp diameter, top-pull style
- Bottom bracket shell: 68mm wide, threaded English 1.37˝ x 24t
- Chainring clearance: No frame limitations. Use whatever you want
- Tire clearance: 26 x 2.5˝ with fenders
- Fork: TIG-welded 4130 CroMoly, tapered and butted straight blade with single fender eyelet on the dropout, 1-1/8˝ x 260mm threadless steerer, 51mm IS disc mount, removable cantilever pivots, line/housing guides
- Cargo Weight Limit: 400 lb combined rider and cargo. Max cargo 200 lb
FORK COMPATIBILITY
- Stem clamp: 28.6mm
- Tire clearance: 26 x 3.0 ̋, individual tire and rim combos affect tire clearance
- Crown race: 30mm
- Front brake rotor: 51mm I.S., 180mm max rotor size
- Front spacing: 100mm
- Axle type: 9mm
- Braze-ons: Mid-and low-blade fully threaded through-blade fork eyelets
Frameset
- Frame: Surly Big Dummy, Surly 4130 CroMoly steel. Main triangle double-butted. TIG-welded cargo specific engineered for stiffness.
- Fork: Surly Big Dummy, TIG-welded 4130 CroMoly, tapered and butted straight bladewith single fender eyelet on the dropout, 1-1/8˝ x 260mm threadless steerer, 51mm IS disc mount, removable cantilever pivots, line/housing guides
- Seatpost clamp: Surly Stainless, 30mm Surly stainless, included
Geometry
| Size | Small (16) | Medium (18) | Large (20) | xLarge (22) |
Seat Tube Length
(Center-Top) | 406.4 | 457.2 | 508.0 | 558.8 |
Top Tube Length
(Center-Center) | 550.6 | 570.1 | 588.7 | 609.6 |
Effective Top Tube Length
(Center-Center) | 573.5 | 596.1 | 614.1 | 631.8 |
| Head Tube Angle | 72.0 | 72.0 | 72.0 | 72.0 |
| Seat Tube Angle | 73.0 | 73.0 | 73.0 | 73.0 |
| BB Drop | 40.0 | 40.0 | 40.0 | 40.0 |
| Chainstay Length | 827.0 | 827.0 | 827.0 | 827.0 |
| Wheelbase | 1435.9 | 1458.8 | 1477.0 | 1495.0 |
| Standover Height | 740.4 | 771.5 | 802.9 | 835.8 |
| Head Tube Length | 131.7 | 145.9 | 160.8 | 178.8 |
| Fork Length | 425.0 | 425.0 | 425.0 | 425.0 |
| Fork Offset | 43.0 | 43.0 | 43.0 | 43.0 |
| Stack | 566.5 | 580.0 | 594.1 | 611.3 |
| Reach | 399.6 | 418.1 | 431.7 | 444.1 |
For measures in Inches,
click here!
All dimensions are preliminary and subject to change
* Standover is measured from the top of the TT, at the center, with a tire measuring approximately Ø676mm
