My Kona Explosif 2008

After using a singlespeed bike assembled with old and budget parts for 6 months, I found myself completely convinced by the concept and decided to build a new bike, based in a dedicated singlespeed frame.

Some online research brought the 2008 Kona Explosif frame to my attention. A nice Cromoly steel frame, with sliding dropouts and well sorted geometry. I also had the luck to find it quite cheap in the wiggle.co.uk online shop. After some further comparison with the alternatives, I found no better deal and as such, a size 19 Explosif frame was delivered to me in July 2008. The frame is relatively heavy as mine weighted 2399 grams (5.3 pounds) with seatcollar and dropouts.


The final setup has changed a bit during the first six months after I received the frame. While I initially assembled it with some components from my previous build, slowly these components were traded for some high quality ones. The final result was this:


The bike rides very nicely and feels precise and quick in the trails. The frame ride is refined and has a distinct feel from the aluminum frame I had before. The custom made Amaro Ti fork was purposefully built with a very short axle-to-crown length (395mm) and large trail (45 mm), values typical of older rigid forks or cyclocross forks. The final result is a low front coupled with the extremely sharp steering due to the steep head angle.A Groovy Cycleworks Luv Handle provides a comfortable yet sporty riding position.

The light v-brakes XTR wheels are shod with large volume Schwalbe Nobby Nick 2.25 tyres. The tires combine with the titanium fork to provide reasonable shock absorption. While not comparable to an actual suspension fork, this setup is very usable and allows more than sufficient control to handle rocky terrain.


The drivetrain uses a XTR crankset converted to singlespeed with a lightweight Salsa 32t ring. The rear cog is a Surly 16t, a high quality component that has almost perfect finish and according to other users should last very long. The chain tension is easy to adjust using the sliding dropouts and I've not experienced any slippage problem that sometimes affects this kind of design. The only drawback with these dropouts is the reduced capability to hold a wheel with the skewers undone. If there is not enough tension in the skewers the wheel can jump out and jam in the frame.

Avid Single Digit 7 v-brakes were used in this ride to reduce cost, complexity, weight and simplify the maintenance. While not as consistent as discs for all-weather use,the power is more than enough and I've always had good experiences with the Avids.

The Explosif frame was discontinued for 2009, and replaced by the Unit 29er.

The full component list: