Hot Chop Speed Shop's Twin-Engine Drag Bike
See how the insanity of twin-engine Harley drag racers of years past inspired a Japanese bike builder to create a crazy cool dragster of his own.
Twin-engined Harley drag bikes have long been tearing up the strips stateside with the earliest examples appearing in the 1960s and eventually evolving into nitro-burning rockets that would blitz the quarter-mile in the blink of an eye. Japan has always had a sort of love affair with Harley-Davidson motorcycles, so it is quite surprising that the Land of the Rising Sun has not seen a home-built twin-engine Harley until Kentaro Nakano recently released his 'Double Trouble' bike to the public.
Home of the Hot Chop Speed Shop
Kentaro Nakano runs the Hot Chop Speed Shop located in Kyoto City, Japan and is said to be highly regarded among Japanese Harley owners of the region. Nakano's drag bike build began in the winter of 2017 as a sort of homage to Harley drag racers of the '70s. It was decided early on that the build would revolve around a pair of 1970s-era XLCH Ironhead engines that originally powered the Sportster.
The first order of business was to rebuild both engines from the bottom-ends up. This was completed by Nakano's friend, Kazuhiro Takahashi, at his Sakai Boring machine shop. The engines were then linked via a set of connecting plates and the output shafts joined to two chain-driven primary drive setups, one of which is from a Big Twin Touring model and the other from a modern Sportster. Perhaps one of the coolest features is that Nakano linked the engines with offset ignition pulses that allow them to run together, much like a four-cylinder as opposed to two linked twins.
The chassis is an entirely custom unit created by Nakano himself, using steel tubing shaped around the stacked twins coupled to a 4-speed gearbox from an 80's touring Harley. The donor forks were supposedly pulled from a late 70s Ducati and were shaved and fitted with custom caliper brackets securing Airheart calipers. The classic laced-aluminum 18" wheels wrapped with a retro bias-ply front tire and old-school M&H rear slick help Nakano achieve that period racer look.
Built for Speed
The cockpit and bodywork are utilitarian and quite minimalistic as any proper racer should be. But that is also what makes the bike attractive. The fuel tank is a simple cylinder-shaped design that wraps around the backbone of the frame. The seat is reminiscent of a bobbed cafe racer unit but also neatly doubles as the engine oil tank. The drag bars and hand controls are custom-built items that sit slightly aft of the 70s Harley tac.
Attention to Detail
The engines each breathe through an S&S Cycles Super B Carburetor with custom velocity stack; a popular setup introduced in the mid-'70s that is still being offered today. The exhaust has simple megaphone designs that fit tightly next to one another and surely scream at full song. Other touches include mechanical oil gauges on each engine's front cylinder rocker box, engraved pressure plate, and various drilled and painted brackets and braces including the kick starter. Who would like to try to kick this beast over?
Ready to Rumble
Nakano released his 'Double Trouble' creation a few weeks back at the Mooneyes show (a.k.a. the Yokohama Hot Rod Custom Show) and gained huge amounts of attention along with awards from Hot Bike and Vibes motorcycle magazines. Nakano explains that the next step is to get the bike out to the drag strip for tuning and test passes. Assuming all goes well, he would like to make a trip to the Bonneville Salt Flats to see how well the bike can do in extended speed runs. We wish him the best of luck with the extracting the speed out of this wild creation!
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