Empowering The Bicycle Traveler

Karate Monkey 27.5 Plus

Surly Bikes as a company cultivates an image of being comprised of hooligans who, between visits to the tattoo/piercing/beard parlor, drink beer and ride bikes through campfires and sleep under bridges. While this describes the surly lot I know, they are also smart business people and engineers who happen to love bikes and bike riding. I think that is why, even if it takes longer than anyone predicted, when new products are rolled out all the bugs have been identified, all the details are considered and finalized, and everything works. Turns out, drinking beer and riding bikes through campfires is a good way to test bikes.

Consider the new Karate Monkey:
Surly Bikes’ Karate Monkey has been around almost as long as the company and in Surly tradition hasn’t changed too much over the years except for a few tweaks here and there. However, the 2017 bikes are hardly recognizable as Karate Monkeys of yore.

surly karate monkey bicycle

The Surly Karate Monkey 27.5+ Complete

The 2017 Karate Monkey has a new geometry:
– The only numbers that stay the same- geometry wise- between the old bike and the new one are the length of the head tubes and the seat tube angle. The new bikes have shorter chain stays, longer top tubes, less bottom bracket drop and slacker head tube angles. Effectively the rider is planted more over the rear wheel with the front wheel relatively far out in front. The wheelbase in the new version for the large bike is 50mm or 2 inches longer. The slack head tube and short stem have the effect of bringing the bars closer to the rider to help make up for the length of the top tube. This is a “modern trail geometry” which is meant to give the rider a combination of confident handling and agile steering.

Surly Dirt Wizard 27.5x3

The complete bikes are offered with two wheel sizes:
– The 1×11 geared version is spec’ed with 27.5+ wheels and tires. The stock tires are 27.5 x 3″ Surly Dirt Wizard with a 60 TPI rating. The bead is folding and the tires have a nylon insert in the sidewall and a new, more durable rubber compound. Surly says the tire is tubeless ready, but the bikes arrive stock with tubes in the tires. The Alex MD40 rims are tubeless compatible too, so to run the tires without tubes, all that’s needed is some tubeless rim tape, a valve stem and some sealant.
Here at Bike Touring News, we think 27.5+ tires (27.5 is the same thing as 650b but sounds more rad, and the +, or plus, means the tires are around 3 inches wide) are the sweet spot for traction and comfort for bikepacking and trail riding.

-The complete, single speed bike uses the identical frame, available in different colors, and 29 inch (700c) rims and tires. Surly also sells frame sets which are compatible with either wheel size.

-Rear Hub
Below we have two videos; one from Hermit’s Workshop and one from Surly Bikes which explain and illustrate Surly’s Gnot Boost rear frame spacing and dropouts. Basically all you need to know is that a standard 142mm thru-axle hub will work as will a 148mm spaced boost hub. With the spacers Surly provides with the frame, a 135mm quick release hub will work too. So for those with some parts on hand or who are taking parts off an existing bike to put on a Karate Monkey frame, chances are good the rear hub will fit.

-Front Hub
The stock fork on the complete bikes and frame sets is designed for a hub with a 15mm thru-axle and 110mm OLD spacing. The fork is also suspension corrected so a suspension fork with 120 or 130mm of travel won’t change the handling/geometry of the bike.

Drive Train
The geared bike uses a 1×11 drive train with a 30 tooth chain ring and 11-42 tooth cassette which should provide a gear low enough to climb all but the steepest grades that will be tackled on most bikepacking trips or single-track riding. The top end will suffer a little bit however compared to 2×10 bike, for example, equipped with a larger, outer chain ring.


1×11 drive train. Very simple. Fantastic.

Ride and Overall Impression
We have the complete bikes with 27.5+ wheels and these are the bikes reviewed here.
The Answer Expert handlebars are WIDE; 790mm on the larger bikes and 730 on the small. Lots of leverage for the technical bits I guess, but they are a little wider than anything I am used to and I’m afraid I would be hooking them on trees on narrow trails. If that was the case they could always be cut shorter.

The Cane Creek headset on the stock bike is pretty generic and seems to require careful alignment and installation of the fork crown race and the headset cups. The headsets on the bikes we received were almost impossible to adjust tight enough to eliminate play without creating a bind when turning the handlebars. We ended up taking the fork crown races off and cleaning the paint and ED coating off the seat area on the fork so the races would press back on flat. That took care of the binding issues.

Karate Monkey tubes

So-called trumpet shaped tubing for extra strength at the head tube.

rear stays Karate Monkey

The rear stays have an elegant, powerful look to them

There is so much ice on the streets right now that I have not been able to ride one very far but weaving around the paths shoveled through the snow here at BTNWHQ I definitely sense that the steering is very quick and responsive. And I can appreciate the simplicity of having one chain ring and only one shifter and rear derailleur.

Visually the bike has an aggressive, powerful, dare I say- surly appearance. The “Rhymes With Orange” color is a home run IMHO- very striking. The frame tubes are sized and manipulated in order to provide the best strength to weight to performance ratios and the complete frame sort of flows together. These bikes just make me want to take a break and go for a ride, and I think that is one good metric by which to judge any bike.

Complete component list and geometries can be found at the Surly website.

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