Beauty might be in the beholder’s eye, but art doesn’t have to be pretty to be striking or intriguing. That applies to everything from paintings and sculptures to cars and motorcycles. But while you can only look at paintings, the best custom bikes are made to be ridden. And as Jay Leno explains in his latest video, that even goes for a motorcycle that almost looks like a sculpture: the Revival Cycles ‘Birdcage’ BMW.
Before BMW rolled out the R 18, Revival Cycles wrapped its boxer engine in a ‘Birdcage’
Often, companies release concepts to preview styling directions. However, BMW took a slightly different tactic when it was getting ready to release the R 18 cruiser.
Before the production bike saw the light of day, BMW sent its 1802cc air/oil-cooled boxer-twin engine to Austin-based Revival Cycles. And it commissioned the shop to build a custom motorcycle to show that big boxer off. The ‘Revival Birdcage’ is the result.
Although Revival Cycle’s Birdcage uses a BMW R 18 powertrain—shaft drive and six-speed transmission included—it’s not actually an R 18. For one, the shop ditched the boxer’s oil-cooling radiator, making the engine strictly air-cooled. Two, it replaced the foot shifter with a custom hand-operated shifter. Three, instead of electronic fuel injection, Revival Cycles installed a mechanical setup with bell-mouth velocity stacks. And, most importantly, the Birdcage isn’t built on an R 18 frame.
Back in the 1950s, the Maserati Birdcage introduced the concept of a tubular lattice ‘space frame’ chassis to the world of racing. And that race car was one of Revival Cycle CEO Alan Stulberg’s main inspirations for the build, Motorcycle Cruiser says. Only instead of steel or aluminum, the Birdcage BMW R 18 has a tubular titanium frame hand-welded out of 134 rods. That’s partially why the custom bike only weighs about 420 lbs, instead of the standard R 18’s 761 lbs.
Revival Cycles went far beyond building a titanium frame to make its Birdcage fly
Stulberg also drew inspiration from 1920s and 1930s land-speed racing bikes, including several vintage BMW machines. And that influence is sprinkled throughout this unique motorcycle, even besides the hand shifter. The front fork tubes and down-turned handlebars, for example, are based on the ones on Ernst Hennes’ land-speed-record-setting BMWs, Ultimate Motorcycling explains. And the Hennes influence shows in the rear wheel, too, with its aluminum-disc covers, Bike Exif notes.
However, while it looks like the Revival Cycles Birdcage has no front suspension, that’s not the case. Stulberg’s team designed it to mimic BMW’s ‘Telelever’ suspension, which separates steering and damping forces using a secondary mono-shock. So, while the Birdcage BMW R 18’s forks are made out of carbon fiber and aluminum, it has an Ohlins mountain bike shock, too. Plus, the lower parts come from a modern BMW 1150GS.
In addition, while the titanium frame is arguably the main reason for the Birdcage BMW R 18’s lack of weight, it’s not the only one. The exhaust is also made out of titanium, as are most of the fasteners. The seat, meanwhile, is solid carbon fiber, as are the handlebars and gear linkage. There’s also no front brake, just a single disc in the rear. Plus, the one-gallon fuel tank—yes, one-gallon—is made of aluminum, as are the valve covers.
It might be impractical, but it’s inspirational to the point of tears
Unfortunately, Jay Leno didn’t get a chance to ride the Revival Cycles Birdcage. However, the custom bike is perfectly functional and rides on prototype 23” slicks straight from Dunlop. And as Stulberg demonstrates in the video above, that boxer is torquey enough to rock the bike at idle. But that Telelever-style suspension means there’s no shimmy at the handlebars. Plus, once you open the throttle, everything goes smooth. “It’s deceptively high-tech,” Stulberg quips.
Given its small fuel tank, single brake, and carbon-fiber seat, this Birdcage BMW R 18 isn’t exactly practical. But then, it’s not supposed to be. Firstly, “I like the art and the science,” Jay Leno says. And he follows up by musing, “You know when you watch one of these crazy fashion shows in Paris? A woman walks out in a hat you couldn’t possibly have on your head? But it inspires other design.” That’s what custom bikes like this are all about. And in a way, a birdcage-style frame is practical, Leno and Stulberg note, due to its lightweight but extremely strong design.
And it appears Revival Cycles’ work made just as much of an impression on BMW’s employees as it did on Jay Leno. After roughly six months of work, Stulberg was understandably nervous about showing the finished build to BMW. But he got “good tears” from at least one German executive during the unveiling.
Can you get your own Revival Cycles ‘Birdcage’ BMW R 18?
Technically, the Revival Birdcage is the property of BMW. And given how many man-hours went into welding that titanium frame, it’s unlikely BMW will ever offer a production bike with one, R 18 or otherwise.
That being said, some custom BMW bikes haven’t remained one-offs. NMoto, for example, sells kits to turn R nineTs into Art Deco-style machines. And Kingston Custom can replicate its custom R 18 if you want. So, maybe if you ask Revival Cycles nicely enough, the shop could build another Birdcage.
After all, a piece of art like this should be ridden, right?
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