NEW Surly Karate Monkey Steel Hardtail Mountain Bike - Lost at Sea - 210000059649
The Karate Monkey Front Suspension bike features a Rock Shox 35 Gold RL A2 suspension fork with 140mm travel, and it’s paired with a dropper post out the box. Progressive trail geometry and Surly’s Gnot-Boost rear dropout system deliver a versatile bike with the ability to swap hubs and wheel sizes. If you want to round-house kick some trail right in the face, the Karate Monkey is your sled.
Features
- 100% Surly Chromoly steel frame, double-butted main triangle and 44mm headtube
- The tubeset uses Surly custom trumpet tubes for greater stiffness and durability
- Adjustable rear dropouts with 145mm Gnot-Boost spacing. Works with 142 and 148 x 12mm thru, as well as 135mm w/ 10/12 washer
- RockShox 35 Gold RL A2 suspension fork with 140mm travel
- TranzX YSP15 dropper post with stealth routing; 100mm travel on XS, 120mm travel on SM–XL
- Complete Bike Weight: 33 lb. 13 oz. for Medium
Specifications
- Frame: Surly Karate Monkey - 4130 Chromoly, Natch tubing, double-butted main triangle, trumpet flared tubes, TIG welded, ED coated
- Fork: RockShox 35 Gold RL, 27.5", 15 x 110mm, 140mm travel, 44mm offset
- Color: Lost at Sea Blue
- Rear Derailleur: Shimano M8100 XT SGS
- Cassette: SunRace CSMZ800, 11-51t, 12spd
- Chain: KMC X12 Anti-Rust
- Crankset: Shimano MT511, 30T
- Bottom Bracket: Shimano MT501, BSA
- Shifter: Shimano Deore XT M8100
- Brakes and Rotors: Tektro HD-M3520, Tektro 180/160, 6-Bolt
- Headset: Cane Creek
- Stem: Promax DA-296, 31.8mm
- Handlebar: Salsa Rustler
- Grips / Bar Tape: Velo Black
- Seatpost: TranzX YSP15, 30.9mm Travel XS: 100mm, SM-XL: 120mm
- Saddle: WTB Volt Medium
- Front Hub: Novatec 15x110mm, 32h
- Rear Hub: Novatec 12x148mm, 32h
- Rims: WTB ST i35 TCS 2.0 27.5"
- Tires: Surly Dirt Wizard 27.5 x 2.8", 60tpi, Tubeless Ready
- Spokes: 14G Black
What our Experts Think
- Highly versatile steel hardtail mountain bike designed for trail riding, bikepacking, commuting, and all-terrain exploration.
- Chromoly steel frame delivers a smooth, durable ride feel that reduces fatigue on rough and technical terrain.
- Compatible with 29" wheels (and 27.5+ setups depending on build), offering flexibility for speed, comfort, or traction-focused builds.
- Trail-ready geometry balances stability on descents with responsive handling in tight, technical sections.
- Suspension-corrected design supports modern fork setups for improved control and capability on rough trails.
- Wide tire clearance allows high-volume tires for enhanced grip, comfort, and year-round versatility.
- Multiple mounting points make it an excellent platform for bikepacking and utility-focused configurations.
- “Lost at Sea” finish adds a distinctive, adventurous aesthetic while maintaining its rugged, utilitarian identity.
Q&A
Q: What type of riding is the Surly Karate Monkey designed for?
A: The Surly Karate Monkey is a highly versatile steel hardtail mountain bike built for trail riding, bikepacking, commuting, and all-around off-road exploration.
Q: What material is the frame made from?
A: It uses 4130 Chromoly steel (Surly Natch tubing), delivering durability, comfort, and a smooth, confidence-inspiring ride on rough terrain.
Q: What wheel sizes does it support?
A: It can run both 27.5+ and 29” wheels, making it adaptable for different terrains, riding styles, and tire preferences.
Q: What makes the Karate Monkey different from other hardtails?
A: Its adjustable geometry and multi-wheel compatibility make it a true “one-bike-does-it-all” platform for riders who value flexibility and long-term usability.
Q: Is it suitable for bikepacking?
A: Yes. It includes multiple mounts for racks, bottles, and gear, making it a strong choice for loaded touring and off-road bikepacking trips.
Q: What terrain is it best for?
A: It handles singletrack, gravel roads, forest trails, and mixed-surface riding with stable yet playful geometry.
Q: What drivetrain does it typically use?
A: It is commonly built with modern wide-range 1x drivetrains for simplicity, reliability, and climbing performance.
Q: Is this bike rigid or suspension-equipped?
A: The Karate Monkey can be built either way, but this version is typically a rigid steel hardtail for simplicity and low maintenance.
Q: What is special about the “Lost at Sea” color?
A: It is a deep, muted blue finish that reflects Surly’s rugged aesthetic while giving the bike a distinctive, understated look.
Q: Who is this bike best for?
A: Riders who want a durable, adaptable steel mountain bike that can handle trails, commuting, and adventure riding without specialization.
Maintenance Tips
Damage 
Loss 
Theft 
