Surly Karate Monkey review

Superb value 29er frame and fork package

Our rating 
3.0 out of 5 star rating 3.0
GBP £999.99 RRP
Surly Karate Monkey

Our review

Single geared bikes will always be love or hate, but the Surly often converts sceptics. You can upgrade to gears
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The Surly Karate Monkey is a steel framed, single-geared 29er, but almost everyone who tries one ends up wanting one. You can add gears and suspension later if you feel the need.


Ride & handling: One gear and no suspension, but with advantages

Surly, as a word, perfectly captures the ride character of the Karate Monkey. It offers solid, dependable handling with a no-nonsense design approach that’ll help to neutralise some riders’ qualms about its lack of suspension and gears.

Inevitably, the lack of suspension requires a deft touch on rough terrain and the lack of gears makes climbing a slog at times. But, as one-gear riders are fond of pointing out, if you persevere on climbs you’ll soon notice your leg power increasing.

And, with a gear that feels spot-on for the majority of steady flattish riding, you’ll soon learn to enjoy freewheeling descents and pedalling like a gym-spinner to justify your choice when trying to keep up elsewhere. Or just spend a bit more money and fit gears.

Most of our testers loved it exactly as it was. The skinny tubed steel frame conspires with big treads run at 30psi to provide a surprisingly comfy ride on rough terrain.   

Frame & equipment: Bombproof and thoroughly adaptble

If you went for a frame and fork package for £379.99, then scouted around for bargain componentry, you could still score a multi-geared and suspension fork-equipped Monkey for less than £1,000. Or you could buy a complete bike package like this.

The frame and fork are decent-quality steel offerings built to accept a fair amount of off-road punishment and designed for heavy-duty utilitarian use as well as mountain biking.

There are nicely placed bosses for a rack, two water bottles and mudguards, as well as plenty of heavy-use-deflecting reinforcements at the head and seat junctures. The lower seat tube is curved forward to create short chainstays with plenty of mud room, and there’s a rear mech hanger plus cable guides for front and rear gear cables.

A straight blade fork has room for the biggest tyres and there’s masses of nads clearance on the top tube. Check sizing carefully; the reach of our 20in bike was more like 18 or 19in frames from other manufacturers.  

Everything supplied on Surly’s complete bike is ripe for fuss-free upgrading if you feel the need – apart from the rear hub, which is single-gear-specific, with a wide body and nutted axle ends for stay-put security in the slotted dropouts.

The wheels are built strong, with Surly’s own hubs, WTB SpeedDisc rims and ExiWolf 2.3in treads – a great choice for comfort, traction and fast rolling. Avid cable pull disc brakes, with full outer cables, are low in terms of maintenance and offer great stopping power and modulation once the pads are bedded in.


Truvativ’s 33-tooth ring, bashguard, outboard bottom bracket and a Shimano 17-tooth freewheel make for a super-tough drivetrain, and all the finishing kit is quality stuff that’s comfy in use and perfectly matches the character of the bike.

Product Specifications


Name Karate Monkey (12)
Brand Surly

Description 16, 18, 20*, 22in
Rear Wheel Weight 2620
Weight (lb) 25.4
Weight (kg) 11.4
Seatpost Surly
Seat Angle 73
Saddle WTB SST
Rims WTB Speed Disc XC
Headset Type Cane Creek 40
Brakes Avid BB7 cable discs, 160mm
Head Angle 72
Handlebar 26.5in Salsa Moto Ace
Front Wheel Weight 2330
Frame Material 4130 chromoly double-butted steel
Cranks Truvativ Firex 33
Chain KMC
Cassette Shimano 17-tooth freewheel
Tyres WTB Exiwolf DNA 2.3in