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Bikes. Parts. Chaos.

The fat tire bike purpose-built for rolling over previously unridden terrain.

When we find ourselves with a deep, primal urge to explore beyond the horizons of our beloved Flat Earth, few things satiate this need. Moonlander is one of them. 

A portal into previously unridden terrain, Moonlander goes where other fat bikes don’t dare, where traction is a supposed myth and the only grams worth saving are in our Dugout Bag.  

Our newly developed, high-volume Molenda tires were key. (Even the fattest in-market tires don’t cut it, and that includes our own line.) Therefore, we equipped this one with 24 x 6.2-inch tires on 100mm rims. Such a large footprint allows us to ride at very low pressure, enabling the ability to float over a geographic smorgasbord of otherworldly terrain. Think rocky dunes, creeping shorelines, frozen beaches, sinuous stretches of snow and the like. 

  • Carefully crafted from our 4130 Chromoly steel, with a bottom bracket height that supplies plenty of clearance for bushwhacking and monster-trucking without losing out on stability 
  • Surly's first bike with a 9-speed Pinion gearbox, an innovative approach to spur gearing that improves reliability and go-anywhere performance with less maintenance 
  • The top tube maximizes standover height and foot dabs into soft substances, while keeping the headtube high so you can set up your rig in a comfortable, all-day-grind riding position 
  • Large volume Surly Molenda Tires on 24 x 100mm Surly Clown Royal Rims inflated by new TPU tubes creates a footprint large enough to float over unrideable (until now) terrain  
  • Clearance for 24 x 6.2” tires, as well as 26 x 5.1”, 27.5 x 4.8”, and 29 x 3” 
  • Comes with rack and fender mounts, as well as accessory mounts on both fork blades to enhance cargo capacity (compatible with our rear disc wide rack) 
  • Weight distribution across front and rear, with a longer back, allows for greater stability 
  • Features Tektro HD-M285 Hydraulic Disc Brake System 
  • Four frame sizes to fit most riders: SM, MD, LG, XL 
  • Includes a dropper for easier on and off, especially on soft surfaces
  • Bike Capabilities

    • 5/5 with Floatation Floatation: 5 out of 5
    • 5/5 with Off-Trail Exploration Off-Trail Exploration: 5 out of 5
    • 4/5 with Bikepacking Bikepacking: 4 out of 5
    • 5/5 with Turning Heads Turning Heads: 5 out of 5

    NOTE: You can ride your bike wherever the hell you want, but this is what we think this bike is best at.

    Surly Moonlander fat bike side view on sand dune
    Person riding Surly Moonlander fat bike down sand dune
    Person riding Surly Moonlander fat bike focus on tires in sand
    Surly Moonlander fat bike close-up of Pinion gearbox, cranks, and bottom bracket area
    Surly Moonlander fat bike wheel standing up in sand
    Person riding Surly Moonlander fat bike across sand dunes shot from above
    Person riding urly Moonlander fat bike down sandy and rocky steps focus on tires
    Surly Moonlander fat bike focus on handlebars and top of bike

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    Where to Buy

    Surly Moonlander fat bike in Lunar Dust Gray side view

    Specifications

    Frameset

    Frame
    4130 Chromoly, Natch tubing, double-butted main triangle, TIG welded, ED coated
    Fork
    4130 Chromoly, Natch tubing, double-butted tapered fork blades, TIG welded, ED coated
    Seatpost Clamp
    Surly Stainless 33.1mm

    Components

    Headset
    Cane Creek 40
    Brakes and rotors
    Tektro HD-M285, Tektro 180/180, 6-Bolt
    Shifter
    Pinion Rotary Shifter
    Stem
    Promax, 31.8, 4-bolt
    Handlebar
    Surly Terminal
    Grip/Tape
    Velo Lock-on
    Saddle
    WTB Volt Medium
    Seatpost
    TransX YSP15JL Dropper, 125mm travel (100mm travel on SM)

    Drivetrain

    Crankset
    Pinion for Surly crankset 34T, with Pinion high-offset spider
    Bottom Bracket
    Pinion Gearbox
    Front Derailleur
    N/A
    Rear Derailleur
    Pinion C1.9 XR 9spd Gearbox
    Cog or cogset
    34t aluminum ring
    Chain
    KMC X10 EPT Anti-Rust

    Wheels

    Front hub
    Novatec 12x197mm, Thru-Axle, 32h
    Rear hub
    Novatec 12x197mm, Thru-Axle, 32h
    Rims
    Surly Clown Royal 24", 100mm wide
    Tires
    Surly Molenda Tire 24 X 6.2”, 60tpi, Tubeless Ready

    Complete bike spec subject to change

    MY25 Moonlander Geo
    units:

    Select a few bike sizes to compare.

    SIZE SM MD LG XL
    Rider Height 5'4"–5'8" 1626–1728 5'7"–6'0" 1702–1829 5'11"–6'3" 1803–1905 6'2"–6'6" 1880–1981
    Reach 15.7 398 16.5 420 17.5 444 18.4 468
    Stack 22.8 578 23.9 606 24.6 625 25.3 644
    Head Tube Angle 68.5° 68.5° 68.5° 68.5°
    Head Tube Length 4.7 120 5.9 150 6.7 170 7.5 190
    Seat Tube Length 14.5 368 16.5 419 18.9 480 20.5 521
    BB Drop 1.8 45 1.8 45 1.8 45 1.8 45
    Wheelbase 47.9 1215 49.1 1248 50.4 1280 51.6 1311
    Chainstay Length 22.1 562 22.1 562 22.1 562 22.1 562
    Top Tube Length, Effective 22.6 575 23.8 605 25.0 635 26.2 665
    Seat Tube Angle 73° 73° 73° 73°
    Standover Height 29.0 736 30.3 769 31.2 793 31.5 801
    BB Height 13.7 349 13.7 349 13.7 349 13.7 349
    Stem Length 2.4 60 2.4 60 2.8 70 3.1 80
    Stem Angle
    Handlebar Width 28.9 735 28.9 735 28.9 735 28.9 735
    Crank Length 6.7 170 6.7 170 6.7 170 6.7 170
    Fork Length 18.1 460 18.1 460 18.1 460 18.1 460
    Fork Rake 2.0 50 2.0 50 2.0 50 2.0 50

    Measurements are based on a: 24 x 6.2 which is the equivalent of an ISO 507 x 152 tire, with an outside diameter of 788

    Design Wheel/Tire Size (Tire Clearance)

    24” x 6.2”

    Alternate Wheel/Tire Size

    26” x 5.1”, 27.5” x 4.8”, 29” x 3”

    Rigid Fork Length

    460 x 50mm

    Front Hub Spacing

    12 x 197mm (Surly axle included)

    Seatpost Diameter

    Ø30.9mm

    Dropper Compatible

    Yes, internal dropper post routing compatible

    Front Derailleur Clamp

    N/A

    Bottom Bracket

    N/A; no frame limitations

    Rear Hub Spacing

    12 x 197mm (Surly axle included)

    Support

    Frame Warranty

    LIMITED WARRANTY

    This Surly product is warranted against defects in materials and workmanship for three years from the date of retail purchase of the product, subject to the limitations detailed below. Save your dated receipt for proof of purchase.

    This warranty does NOT cover the following:

    • Damage due to improper assembly or follow-up maintenance or lack of skill, competence or experience of the user or assembler
    • Products that have been modified, neglected, used in competition or for commercial purposes, misused or abused, involved in accidents or anything other than normal use
    • Installation of components, parts or accessories not originally intended for or compatible with bicycle as sold
    • Damage or deterioration to the paint, surface finish, aesthetics or appearance of the product
    • Normal wear and tear
    • Labor required to remove and/or refit and re-adjust the product within the bicycle assembly

    This limited warranty is expressly limited to the repair or replacement of a defective product, at the option of Surly, and is the sole remedy of the warranty. This limited warranty applies only to the original purchaser of the Surly product and is not transferrable. This warranty applies only to products purchased through an authorized dealer or distributor. In no event shall Surly be liable for any loss, inconvenience or damage, whether direct, incidental, consequential, or otherwise resulting from breach of any express or implied warranty or condition, of merchantability, fitness for a particular purpose, or otherwise with respect to our products except as set forth herein.

    This limited warranty gives the consumer specific legal rights, and those rights and other rights may vary from place to place. This limited warranty does not affect your statutory rights.

    TO THE EXTENT NOT PROHIBITED BY LAW, THESE WARRANTIES ARE EXCLUSIVE AND THERE ARE NO OTHER EXPRESS OR IMPLIED WARRANTIES OR CONDITIONS INCLUDING WARRANTIES OR CONDITIONS OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.