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Karate Monkey is a highly-versatile trail bike that plays the part of 29er and 27.5+ equally well.

Multipurpose Hardtail Mountain Bike

Karate Monkey delivers a resilient, lively ride on all sorts of gnarly terrain. Its frame is a highly-versatile canvas for whatever dirty masterpiece your brain cooks up. According to our computing machine (Thor) it can be set up in approximately 487 different configurations.

Originally designed as a 29er (and the frame that helped spark the 29” wheel movement), the latest Karate Monkey is designed to perform just as admirably as a 27.5+ rig as well. This allows you to pick your poison — provided your poison is having a really great time while permanently donning a shit-eating grin, of course.

  • Modern trail standards: dropper post compatibility, 44mm headtube, Gnot-Boost rear spacing, thru-axles, suspension corrected fork
  • Compatibility with most mountain bike standards makes it the perfect parts bin bike (no rim brakes allowed though)
  • Clearance for 29” x 2.5” or 27.5” x 3” tires

Bike Capabilities

  • 5/5 with Singletrack Singletrack: 5 out of 5
  • 4/5 with Bikepacking Bikepacking: 4 out of 5
  • 3/5 with Commuting Commuting: 3 out of 5
  • 4/5 with Tire Clearance Tire Clearance: 4 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.

Karate Monkey complete bikes, front suspension and rigid
Karate Monkey on dirt
Karate Monkey on built up wooden boardwalk trail in woods
Karate Monkey nunchucks decal - Fool's Gold
Karate Monkey seatstay / tire clearance
Karate Monkey headtube / front-end
Karate Monkey front suspension, High Fiber Green
Karate Monkey rigid, Fool's Gold

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Where to Buy

Karate Monkey front suspension bike, High Fiber Green

Specifications

Frameset

Frame

Custom double butted externally flaired tubing. Horizontal slotted with derailleur hanger, Surly “Gnot Boost” 142 or 148mm hub spacing compatibility

Fork

27.5 - 140mm travel, 44mm offset, 15 x 110mm Axle, disc

Seatpost Clamp
Surly stainless, 33.1mm

Components

Headset
Cane Creek 15
Brakes
Tektro Gemini HD-M520
Brake Levers
Tektro Gemini HD-M520
Rotors
Tektro 180/160mm
Shifter
Shimano Deore XT, SL-M8100
Stem
Promax 31.8
Handlebar
Salsa Rustler without logo
Grips
Velo - lock on
Saddle
WTB Volt 142
Seatpost
TranzX SP15, dropper post 120mm travel, 30.9

Drivetrain

Crankset
Shimano Deore FC-M6100-1, 30t
Bottom Bracket
Shimano, included with crankset
Front Derailleur
N/A
Rear Derailleur
Shimano Deore XT, RD-M8100, 12-speed
Cog or Cogset
SunRace CSMZ800, 11-51t, 12-Speed
Chain
KMC X12, NP/BK

Wheels

Front Hub
110mm, Novatec, 32h, Thru-Axle
Rear Hub
148mm, Novatec, 32h, Thru-Axle
Rims
WTB ST i35 TCS
Tires
Surly Dirt Wizard 27 x 2.8", 60tpi Tubeless Ready

Frameset

Frame

Custom double butted externally flaired tubing. Horizontal slotted with derailleur hanger, Surly “Gnot Boost” 142 or 148mm hub spacing compatibility

Fork

483mm axle-to-crown x 47mm offset, 110mm hub spacing, tapered and butted straight blade. 51mm I.S. disc mount

Seatpost Clamp
Surly stainless, 33.1mm

Components

Headset
Cane Creek 15
Brakes
Tektro HD-M275
Brake Levers
Tektro HD-M275
Rotors
Tektro 180/160mm
Shifter
Shimano Deore SL-M6100
Stem
Promax 31.8
Handlebar
Salsa Rustler without logo
Grips
Velo - lock on
Saddle
WTB Volt 142
Seatpost
Promax 30.9

Drivetrain

Crankset
Shimano Deore FC-MT510-1, 30t
Bottom Bracket
Shimano, included with crankset
Front Derailleur
N/A
Rear Derailleur
Shimano Deore RD-M6100, 12-speed
Cog or cogset
SunRace CSMZ800, 11-51t, 12-Speed
Chain
KMC X12, NP/BK

Wheels

Front Hub
110mm, Novatec, 32h, Thru-Axle
Rear Hub
148mm, Novatec, 32h, Thru-Axle
Rims
WTB ST i40 TCS
Tires
Surly Dirt Wizard 27 x 3", 60 tpi, Tubeless Ready

Complete bike spec subject to change

MY21 Karate Monkey Front Suspension - Geo
units:

Select a few bike sizes to compare.

SIZE XS SM MD LG XL
Reach 14.2 361 15.2 387 16.2 412 17.1 434 18.0 457
Stack 23.9 607 23.9 607 23.9 608 24.3 617 24.7 627
Head Tube Angle 67.5° 67.5° 67.5° 67.5° 67.5°
Head Tube Length 3.9 100 3.9 100 3.9 100 4.3 110 4.7 120
Seat Tube Length 13.0 330 14.5 368 16.5 419 18.5 470 20.5 521
BB Drop 1.7 44 1.7 44 1.7 44 1.7 44 1.7 44
Wheelbase 42.2 1071 43.1 1096 44.1 1121 45.2 1147 46.1 1172
Chainstay Length 16.7 423 16.7 423 16.7 423 16.7 423 16.7 423
Top Tube Length, Actual 21.6 549.7 22.1 560.4 22.6 575 23.5 597.5 24.6 624.5
Top Tube Length, Effective 22.2 565 23.2 590 24.2 615 25.2 640 26.2 665
Seat Tube Angle 71.5° 71.5° 71.5° 71.5° 71.5°
Standover Height 29.8 757 30.5 775 31.4 797 32.5 826 33.7 855
Stem Length 2.4 60 2.8 70 2.8 70 2.8 70 3.1 80
Stem Angle 7° 7° 7° 7° 7°
Handlebar Width 29.5 750 29.5 750 31.5 800 31.5 800 31.5 800
Crank Length 6.7 170 6.7 170 6.9 175 6.9 175 6.9 175
Fork Length 20.5 521 20.5 521 20.5 521 20.5 521 20.5 521
Fork Rake 2.0 51 2.0 51 2.0 51 2.0 51 2.0 51

Select a few bike sizes to compare.

SIZE XS SM MD LG XL
Reach 14.8 377 15.8 402 16.8 427 17.7 450 18.6 472
Stack 23.5 597 23.5 597 23.5 597 23.9 606 24.2 615
Head Tube Angle 69.0° 69.0° 69.0° 69.0° 69.0°
Head Tube Length 3.9 100 3.9 100 3.9 100 4.3 110 4.7 120
Seat Tube Length 13.0 330 14.5 368 16.5 419 18.5 470 20.5 521
BB Drop 2.2 55 2.2 55 2.2 55 2.2 55 2.2 55
Wheelbase 41.5 1053 42.4 1078 43.4 1103 44.4 1129 45.5 1155
Chainstay Length 16.7 423 16.7 423 16.7 423 16.7 423 16.7 423
Top Tube Length, Actual 21.6 549.7 22.1 560.4 22.6 575 23.5 597.5 24.6 624.5
Top Tube Length, Effective 22.0 560 23.0 585 24.0 610 25.0 635 26.0 660
Seat Tube Angle 73.0° 73.0° 73.0° 73.0° 73.0°
Standover Height 29.3 743 29.9 759 30.8 783 32.0 812 32.6 827
Stem Length 2.4 60 2.8 70 2.8 70 2.8 70 3.1 80
Stem Angle 7° 7° 7° 7° 7°
Handlebar Width 29.5 750 29.5 750 31.5 800 31.5 800 31.5 800
Crank Length 6.7 170 6.7 170 6.9 175 6.9 175 6.9 175
Fork Length 19.0 483 19.0 483 19.0 483 19.0 483 19.0 483
Fork Rake 1.9 47 1.9 47 1.9 47 1.9 47 1.9 47

*Standover is measured from the top of the TT, at the center, with a tire measuring approximately Ø749mm

Frame Construction

4130 Chromoly, Natch tubing, double-butted main triangle, trumpet flared tubes, TIG welded, ED coated

Fork Construction

4130 Chromoly, Natch tubing, double-butted tapered fork blades, TIG welded, ED coated

Rear Dropout Configuration

Horizontal slotted with optional vertical dumpout

Rear Hub Spacing

"Gnot-Boost" 145mm
12 x 142mm or 12 x 148mm (Surly axle included)
10 x 135mm with Surly 10/12 Adapter Washers (not included)

Front Hub Spacing

15 x 110mm (Surly axle included)

Rear Brake

Disc - 51mm I.S. (203mm max rotor)

Front Brake

Disc - 51mm I.S. (203mm max rotor)

Head Tube

Ø44mm

Steerer Tube

Ø28.6mm (1-1/8")

Crown Race

Ø30mm (1-1/8")

Stock Headset Upper (S.H.I.S)

ZS44/28.6

Stock Headset Lower (S.H.I.S)

EC44/30

Seat Collar

Ø33.1mm

Seatpost

Ø30.9mm

Front Derailleur (Clamp)

High direct mount top-pull (Ø34.9mm)
26mm offset adapter (not included) for 142 or 135mm rear hub spacing
29mm offset adapter (not included) for 148mm rear hub spacing

Max Chainring (CL) [3]

1x (Mtn):  28T
2x (Mtn):  24/34T
1x (Boost):  32T
2x (Boost):  24/36T

Bottom Bracket

73mm threaded (1.37" x 24TPI)

Tire Clearance Frame [1]/[2]

27.5 x 3.0”
29 x 2.5"

Tire Clearance - Rigid Fork [1][5]

29 x 3.0”

Rigid Fork Spec

483 x 47mm

Max Suspension Fork Length [4]

551 x 51mm (27.5+ 140mm)

Bottle Mounts Frame

1 Standard + 1 Three-Pack (XS - M)
2 Standard + 1 Three-Pack (L - XL)

Bottle Mounts Fork

2 Three-Pack

Rack Mounts Frame

Yes (upper and lower threaded)

Rack Mounts Fork

Yes (upper, lower, and mid-blade threaded)

Fender Mounts Frame

Yes

Fender Mounts Fork

N/A

Other Features

Internal dropper post routing compatible

  • [1] Different tire and rim combinations will result in different clearances.  
    [2] Depending on drivetrain configuration, tire clearance may be limited by the chain and not the frame.
    [3] Listed chainring clearance is worst-case scenario.  Clearances vary widely depending on components and configurations.
    [4] Suspension fork length listed at full extension (not at sag)
    [5] For suspension fork tire clearance, please reference the fork manufacturer's website.

FAQ & Reviews

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.