Out of the Box Thinking with RK Chain
When it comes to custom bikes, builders are often described as ‘thinking outside of the box’ when it comes to more radical looking machines. In the case of Rafik Kaissi of RK Concepts he’s not just thinking outside of the box, he has thrown it away. Designed to look as though it has been made from a giant transmission chain ‘RK Chain’ defies all the conventions of regular custom bike thinking and in doing so finished 10th at the World Championship of Custom Bike Building
There are certain features that can often be found on the very best show bikes; such things as using the engine as a stressed member, front suspension that uses leaf springs, air ride rear suspension, and gas and oil tanks not placed in the regular locations. While all of these features can be found on RK Chain, the bike built by Rafik Kaissi, the owner of RK Concepts, uses them in ways that have not been seen before.
The most obvious design aspect of the bike, and the one that gives it its name, is the backbone of the bike. To call it a frame would be a misnomer as it uses the engine as a stressed member. Created from tubes and plates welded together and detailed to look like chain links. it runs from the headstock to the back of the transmission. Then bolted to the back of the gearbox is bracket to hold the battery and act as a pivot for a second, smaller reproduction of chain links which create the bike’s swingarm. This in turn is suspended by a single large volume air shock under the minimal metal seat.
Given the unconventional design of the ‘frame’ a regular telescopic fork would have looked out of place, not to mention undersized. To counter this problem and give visual balance to the bike, Rafik built his own unique front end. The triple trees bolt to a pair of over-sized, box-section tubes to which are clamped a pair of single leaf, leaf springs, one per side. The lower end of each leaf has then been worked round to form a loop that the front axle passes through.
In order to get the project rolling Rafik ordered a set of wheels from Wheels4Choppers; a front 2.5 x 19in and a rear 14 x 18in. In order to cover the wide rear wheel a Vee Rubber 360-section tire was fitted.
Stopping the bike is all done by the brake on the rear wheel, leaving the front end clean and uncluttered. A Braking rotor has been mounted to the rim of the wheel and it is gripped by a Buell caliper. This is operated by the right hand lever on the bars, which features a master cylinder made from old hand grenade.
In order to use the engine as a stressed member, the engine of choice needed to be a Buell 1200. The choice further aided by the fact that it utilizes unit construction; the gearbox being integrated into the engine cases. This allowed Rafik to pivot the swingarm off a bracket mounted to the rear of the cases. That mount also provides a space for the bike’s battery. While basically stock, the motor has been fitted with a Mikuni carb on a custom manifold and a set of pipes that exit to the left side of the bike. The only other change to the drivetrain was the addition of an extended drive shaft to allow the final drive chain to clear the rear tire.
Even though the motive power of RK Chain is relatively conventional, the bodywork like the frame is not. Due to the unique design of the bike’s backbone a regular style gas tank was out of the question. The solution to this problem that Rafik came up with was to create an entirely separate tank. When he rides the bike he dons a backpack made from an old fire extinguisher that acts as a gas tank and plugs a gas line from the pack into the carb.
Similarly due to space restrictions because of the frame’s design the oil bag has been relocated to the front of the bike.
RK Chain was a significant bike at the 2009 World Championship of Custom Bike Building for it represented yet another new emerging style form a previously unknown young builder. And it is young builders like Rafik Kaissi bringing challenging designs like RK Chain into the public eye that will keep the custom scene vibrant and fresh.