High-Buck Hack
High-Buck Hack
Slip-slidin' away in the world's most expensive sidecar
BRIAN CATTERSON
THREE-WHEELERS ARE for kids, right? Tricycles on which to begin one's progression to bicycles and, eventually, motorcycles? Once past that glorious Saturday when your dad unbolted the training wheels from your Stingray and spent the afternoon chasing you up and down the street, was no turning back.
Or is there? A Swiss gentleman by the name of Walter Gruter would beg to differ. His company, Gruter & Gut Motorradtechnik (GG for short), produces what is perhaps the world’s most sophisticated and exclusive three-wheeler, the Duetto sidecar.
How sophisticated? Very. Among the Duetto’s many high-tech touches are hub-center steering, single-sided swingarm front suspension and three-wheel anti-lock brakes. How exclusive? Again, very. Retail price is 59,650 Swiss francs-just over $50,000 at present exchange rates. Hardly a tricycle, now, is it?
Established in Ballwil, Switzerland, in 1983, GG deals primarily in BMWs and Italian motorcycles. Originally, the business was run by two partners, but the second, Daniel Gut, was killed in a sidecar accident a few years ago. These days, the 20-person operation has grown to be much more than a dealership, as its fully equipped machine shop churns out beautifully crafted hop-up parts for all manner of European motorcycles, most notably Moto Guzzis.
Featured attraction is, however, the Duetto. In a true labor of love, Gruter worked on the Duetto for seven years before settling on the final design shown here. Along the way, various configurations were tried and discarded; the front swingarm, for example, was originally welded up from steel tubing before being replaced with one machined from billet aluminum and, finally, with a less-expensive cast-aluminum piece.
The swingarm is one of the few places you’ll find any such cost-cutting concerns on the Duetto-“spare no expense” appears to have been the battle cry. Starting out with a stock BMW K1100LT, Gruter discards the bike’s fork, wheels and bodywork. He then bolts a pair of machined aluminum sideplates to the front of the laydo wn-Four and attaches the front swingarm, the brakestay arm, and the steering and suspension linkages to those. A fully adjustable, remote-reservoir WP shock takes care of the bump-absorption duties.
The trickery doesn’t stop there, either. As your eyes move forward, you can't help but be mesmerized by the front brake. The exquisite eight-piston caliper is machined from aluminum billet in-house, and grasps a massive venti lated rotor. The three-spoke aluminum wheels are equally gor geous. Manufactured to GG's speci fications by Marchesini in Italy, these measure 6x14 inches on the front of the bike and sidecar, 6x15 inches in the rear. Dunlop car tires
are mounted all the way around.
As for the sidecar, its low-slung chassis is constructed of square-section steel tubing, attached to the bike’s frame at four points—two below the engine and, using tie-rods, two above. Suspension is trapezoid-type, again with a fully adjustable WP shock. The car’s brake consists of a Brembo two-piston setup identical to that used on the rear of the bike. BMW’s effective anti-lock brake components grace all three wheels. Inboard of the sidecar wheel, you’ll find a 10gallon aluminum fuel tank with an electric pump and a large, car-type battery, so positioned to help keep the sidecar wheel on the ground. More on that later.
It’s almost a shame to hide all the beautiful machine work that goes into the GG Duetto, but the coachwork is no less breathtaking. Made of GFK-laminate plastic, there is no visible hardware securing the body to the frame-it’s all hidden underneath.
The motorcycle body features a half-fairing with a vestigial windscreen, plus a dummy fuel tank with a locking storage compartment. The louvered sidecar body resembles a Ferrari Testarossa from some angles and utilizes the KllOOLT’s height-adjustable electric windscreen. A hinged hood eases passenger access, while the trunk opens via an electric switch in the cockpit and the spring-loaded fuel filler cap pops open with a light push. The plushly carpeted interior is fairly roomy (though 6-footers will bang their knees on the hood) and includes a comfortable BMW car seat. The entire sidecar body
lifts up off the chassis on hydraulic prop rods to ease battery or suspension maintenance.
If a description of the Duetto isn’t enough to change your perception of three-wheelers, a test ride certainly will, as I discovered when I ventured to Seattle, Washington, to try one out. Ride West BMW (7020 Woodlawn Ave. NE, Seattle, WA 98115; 206/527-5511) is the nearest thing to a U.S. importer, and had in its possession the only unit in North America. Yes, had: We tested the unit shortly before its “visa” ran out and it was returned to Europe. Trouble is, this meant traveling to Seattle in March, hardly the time of year to visit the sodden Pacific Northwest. Thus, my wife Joanie, photographer Brian Blades and I spent the majority of our time bundled up in sweatshirts and rain gear.
The first thing you need to know about sidecars is that it’s impolite to refer to your passenger as a “monkey’-particularly when said passenger is your wife! The next thing you need to know is how to operate the contraption, because most of what you know about riding a bike-or even driving a car-goes right out the window.
The easiest way to explain the sensation is to imagine a friend riding his bike alongside yours. Accelerate and you’ll pull away from him; decelerate and you’ll fall behind. The same thing happens with a sidecar, except that because it’s attached, it’s constantly attempting to pull the bike in one direction or the other. Naturally, each of these motions calls for a corrective steering input. Now that you understand that, real ize this: Using the brakes changes everything. With the hand lever oper ating the bike's front brake and the foot pedal actuating the bike's rear brake plus the one on the sidecar, using one control without the other produces all sorts of weird twitching effects. They don't call racing side cars "worms" for nothing, you know.
Besides being 50 percent wider than a typical bike tire, the Duetto’s front Dunlop also has a square cross-section, meaning that the contact patch extends from one shoulder to the other. In comparison, only a small portion of a bike’s tire, with its rounded cross-section, touches the pavement at a given time. This means that it takes a lot of effort to steer the Duetto, in spite of the leverage afforded by its wide tubular handlebar. And, no, countersteering doesn’t work: You turn the front wheel in the direction you want to go, just like a car. Considering the intricate linkage connecting the handlebar to the front wheel, you’d expect the steering to be vague, but this is not at all the case. You can clearly feel the front tire squirming, particularly when it’s understeering.
The good thing about having three wide tires, as opposed to two skinny ones, is that you have way more traction. This means that you can rail comers like a racecar. Correction: You can rail left-hand comers like a racecar; right-handers are another story entirely. Because the Duetto’s sidecar is mounted on the right, weight shifts to the car wheel in lefts, forcing it down to the pavement. Conversely, in rights, the shift ing weight attempts to lift the car wheel off the ground. Given the chance, the Consumer Product Safety Commission
would no doubt dub the Duetto “inherently unstable,” like it did with ATVs a decade ago. But that wouldn’t be accurate; the sidecar’s lower center of gravity makes it exponentially more difficult to topple over.
Joey Chitwood impressions notwithstanding, the Duetto is highly entertaining. The familiar BMW liquid-cooled, 1092cc, 16-valve, dohc inline-Four chums out approximately 90 horsepower, which is plenty potent to propel the 900pound rig. No, the Duetto does not accelerate as quickly as a standard K-bike, but it makes up for it in other ways. For example, without the fear of high-siding that accompanies riding a high-performance two-wheeler, you can be pretty liberal with throttle applications. In time, you’ll find yourself powersliding out of comers and spinning donuts instead of making U-tums.
One side-effect of these antics is that the ABS goes into panic mode if the wheel-speed sensors get too far out of synch. Normally, turning the ignition on and off will reset it. but after doing this a number of times while getting squirre ly for photos, our test unit’s system shut down altogether.
Riding the Duetto with the ABS disabled did add another dimension to our test, however, as it made us appreciate the security that anti-lock brakes afford on slick roads such as those we encountered in Seattle. But as sketchy as the conditions were on the sidecar, they would have been much more so on a bike. And therein lies the real beauty of a sidecar: When bike riders are putting away their steeds for winter, sidecarists continue on. You can’t beat hacks for all-season commuting, especially when you consider that they’re legally considered motorcycles, which means that you can use carpool lanes and pay lower tolls.
Still, the Duetto may have more in common with a Lamborghini Diablo than any motorcycle. This thing turns more heads than a topless jogger. Everywhere we went, onlookers did double-takes and flashed us the thumbs-up; even a middle-aged meter maid wanted her picture taken with it!
But one uninformed bystander summed it up best. As we were preparing to leave our hotel one morning, we were surrounded by a group of curious Japanese tourists. Feeling the need to say something, anything, to break the ice, their American tour leader sauntered over and muttered, “Is that something special?”
I wanted to laugh out loud and sarcastically reply, “No, it’s just your average, everyday, $50,000, canary-yellow, fuel-injected, three-wheeled, hub-center-steered BMW, is all.” But I didn’t. Instead, I calmly explained to him that it was a standard motorcycle, painstakingly modified in Switzerland by a breed of people who have, over the centuries, developed an appreciation for fine mechanical devices, like Swiss watches.
When told how much it cost, he was utterly dumbfounded. I couldn’t help noticing that he was wearing a Timex. □
