The Exodus, by Suprine: A recumbent motorcycle powered by BMW
The Exodus recumbent motorcycle, by US company Suprine, is a 130-horsepower lay-back motorbike with a roll cage and a perspex windscreen. It's a radical design with a street-legal prototype already in action, and its remarkable form factor allows it to make a fantastic 80-plus miles per gallon on the highway, while looking like something out of a Japanese anime movie.
I think we'll file this under "nice execution of an odd idea." We see a lot of strange motorcycle concepts here at Gizmag, many of which never make it past the CGI stage. This is often for good reason. Motorcycles don't appear to be evolving particularly quickly at this point, so it's tempting to propose wild new designs, but at the end of the day the standard motorbike as we know it seems to still have an edge over competing ideas when it comes to real-world use and practicality.
One design that has made it through to a working prototype stage is this one, the Suprine Exodus. Built in Baltimore in the United States, the Exodus is a naked, recumbent motorcycle with a large windshield and a tubular steel spaceframe with a protective roll-cage.
Built around a 1200-cc four-cylinder BMW engine, presumably out of the K1200LT tourer, the Exodus also incorporates the BMW's shaft drive and paralever rear suspension. Front suspension is a pair of raked-out telescopic forks and the gearbox is a five-speed with reverse – which I can imagine would come in very handy.
The cockpit features an aluminum racing bucket seat that puts the rider's backside just 7 inches off the ground. Initially, the Exodus is conceived as a bare-bones, naked celebration of engineering, but you can easily envisage it becoming an enclosed riding cabin in future releases.
The rider's feet are free to touch the ground and hold the bike upright at the lights, although the seating position looks like it'd make this a bit of a challenge. When it's moving, you pop your feet up onto a set of cruiser-style forward controls and off you go. Parking the bike requires an electrically operated centrestand (there's no side stand) so you've clearly got to pick a good flat spot.
Benefits of the recumbent motorcycle design
The Exodus has been built to achieve rider comfort, aerodynamic efficiency, high gas mileage, enhanced rider safety and a low centre of mass. Probably its most impressive achievement is its claimed 80mpg (less than 3 litres per 100km) gas mileage - that's roughly twice the bang for buck I get out of my 2002 FZS1000, even when I'm being good.
The gas mileage is mainly a function of aerodynamics - with the rider sitting low in the frame and behind a smooth clear windshield, the Exodus has roughly 50% less frontal area than a regular motorbike, and its bullet-shaped profile no doubt helps it slip through the air even easier.
Drawbacks of the recumbent motorcycle design
While the aerodynamics look really handy for extended freeway riding, drag racing and land speed record runs, to me the Exodus looks wildly impractical for day to day use.
For starters, the wheelbase looks to be well over 2 m (6.6 ft) long. Combined with the extreme rake of the forks, I'd expect the Exodus to execute a u-turn in roughly the same distance as a nuclear icebreaker. It's also big and heavy, weighing in at 680 lb (308 kg). Granted, it's lighter than the 761-lb K1200LT donor bike, but then, in your recumbent position, you really only have your calf muscles to hold it up with.
Then there's the safety element. It's open to debate whether a rider is safer crashing in an enclosed metal frame or separating from the vehicle and doing the old Superman impersonation in a collision. But in terms of passive safety, one of the motorcyclist's key advantages is sitting higher than most car drivers, allowing you to see over the cars in front of you and read traffic two or three cars forward in the line. The Exodus puts you at tailpipe level even if you're following a compact sedan. With less information to work with, you'll need to leave a significantly bigger gap in front of you to maintain the same level of safety.
As with all non-standard vehicle designs, the proof will be in the pudding, but the Suprine team can rightly be proud to have reached the street-legal prototype stage. The bike's engineering looks sturdy and the finish looks tough and futuristic, with a function-over-form approach that I always appreciate.
I'd certainly be game to take the Exodus out for a test ride as it'd be fascinating to see how such a thing would handle. But for now I'll keep my imaginary US$55,000 in my pocket and see how it develops.
You can see a video of the Exodus on the racetrack below.
More information at the Suprine website.
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One thing: " Parking the bike requires an electrically operated center stand (there's no side stand) so you've clearly got to pick a good flat spot." Its begging for gyro stabilization, so give it what it needs.
A flywheel powered from the main drive can continue to keep the bike steady for a minute or so while the driver dismounts or lowers the mechanical supports. Gyro stabilization might offer the second benefit of being able to control a drift if things go pear shaped.
Also, I know the theme is economy, and nothing has to deviate from this. But placing the driver in front begs for the mother of all engines.
Maybe something rotary with a turbo, or a alcohol fed gas turbine. I'll be honest, the only thing I'd ever want to do sitting in this position is test the grip and upper speed limit.
It really seems like it should be a couple feet shorter, though. They seem to have kept the donor powertrain intact, and that makes it much longer than it should be.
Or a non-gyro version of the Lit Motors vehicle: http://litmotors.com/
I really think a serious vehicle needs to be fully enclosed. This is fine for a street legal version of a snow machine or a 4 wheeler, basically something to play around on, but not to use every day or long distances.
I drive a low seat, low CG EV MC with just a 1' stretch so a passenger could sit low too for 78'' wheelbase IIRC, and it's just not smart go over a few '' longer than that as impossible to turn in close in normal spaces, roads. Just try to park it in many spots ;^p
His problem is picking the wrong too long motor/trans and it being in the rear forced the length. The only place for this is the freeway or a drag strip. Outside of those it's just a pain.