2015 Polaris Slingshot 3-Wheeled Motorcycle Review

With the 2015 Polaris Slingshot 3-wheeled motorcycle, Polaris blurs the line between sportbike and lightweight sports car.

2015 Polaris Slingshot in-action photo

Polaris introduced 26 new vehicles in 2013 and is on a path to rack up more than $4 billion in sales for 2014. Clearly, the Minnesota-based company is in a position to experiment and have some fun. Case in point: the new 2015 Polaris Slingshot, a dramatic 3-wheeled motorcycle that goes into production this fall.

In development for three years, the Slingshot is not Polaris' Can-Am Spyder. Rather, the 1,666-lb. trike is more akin to the Compagna T-Rex or a three-wheeled car with front wheels situated way out in front of the driver. You don't straddle the rear-drive Slingshot; you sit way back in it, side by side with your passenger in waterproof bucket seats, and your posteriors are only 11.9 inches off the pavement. With its short windscreen and low-sided open-air cockpit, the Slingshot has the visceral appeal of a sportbike, but it drives more like a lightweight sports car, albeit one with three wheels.

Beneath the polymer body panels is a space-frame chassis made of tubular high-strength steel. In back, a large, single-sided cast aluminum swingarm is controlled by a massive coil-over Sachs damper. In front (where the track is a substantial 69.1 inches—some 6 in. wider than a C7 Corvette’s), forged unequal-length aluminum A-arms team with coil-over Sachs shocks and a huge anti-roll bar that is employed to keep the single rear wheel as flat as possible on the pavement. While increased front roll stiffness typically would cause the Slingshot to understeer, or push, Polaris dials in a healthy amount of negative camber, 2.0 degrees, to make sure the Slingshot goes where it’s pointed. The base $19,999 Slingshot wears 205/50R-17 front tires and a 265/35R-18 rear; the upmarket $23,999 SL (with a stereo and windscreen, among other items), has a 255/35R-20 rear and 225/45R-18 fronts.

2015 Polaris Slingshot stripped view

Mass centralization, says Polaris, was key. The battery is mounted low, just aft of the driver’s seat. More significant, the GM-sourced 2.4-liter inline-4, a dohc aluminum-block Ecotec powerplant, mounts longitudinally just aft of the front axle, where it sends power (a claimed 170 hp and 155 pound-feet of torque) to the rear wheel via an Aisin five-speed manual transmission with a classic H-pattern. From there, a short driveshaft sends power rearward to a bevel gear, and it then reaches the rear wheel via a toothed rubber belt reinforced with carbon fiber.

Although Polaris hasn’t revealed the exact weight balance of the Slingshot 3-wheeled motorcycle, engineer James Holroyd says the rear wheel carries between 34 to 41 percent of the vehicle’s weight, which we can presume is the difference between the vehicle unoccupied and occupied. If too much weight is on the rear tire, the Slingshot won’t want to turn. Conversely, if the Slingshot is too front-heavy, the unloaded rear will have a tendency to snap out in corners.

But that won’t happen in the Slingshot. Stability control is standard, and the Bosch system keeps the Slingshot in line without being intrusive. With stability switched off, the Slingshot felt neutral on the Polaris skidpad, able to be teased into mild understeer or oversteer with simple throttle and steering inputs. Just as important, the transitions were smooth, making the Slingshot feel stable at all times. Although there’s a hint of initial body roll, it’s well snubbed by that meaty front bar. Simulated panic stops from speed are drama-free affairs, thanks to firm three-wheel disc brakes and ABS.

2015 Polaris Slingshot static photo

Traction control is also standard. Even when it’s on, some wheel slip is allowed, just enough to leave a long black stripe on the pavement and make it look like you’ve launched the Slingshot more than a few times. Do remember, though, that this engine has a lot of torque, and, with TC off, it’s all too easy to overwhelm that lone Kenda, which has been developed specifically as a high-performance three-season tire for the Slingshot.

On roads outside of Polaris’ Wyoming, Minnesota, R&D facility, the 2015 Polaris Slingshot was remarkably easy to drive, nothing cantankerous or awkward about it. Although it’s not exactly sportbike quick, the Slingshot has plenty of power, and it’s a kick to see the road blurring by so close to your elbow. The small windscreen directs most of the air up and over your helmet, and the tilt steering wheel allows the Slingshot to accommodate most anybody. The electric-assist steering felt a little heavier than expected, and the transmission, apart from having an unusually wide center gate, boasts easy-to-find gears. Moreover, the light-effort clutch feels natural, and the pedals are arranged for easy heel-toe downshifting. In shoes, not boots.

Because the Slingshot feels more like a car than a 3-wheeled motorcycle, I perhaps unfairly expected an automotive level of sophistication inside. Not the case. What I saw on this prototytpe model was the fit and finish and all-weather durability of a good side-by-side, together with column-mounted instruments from the Victory parts bin. The manually adjustable seats, with three-point safety belts, offer good comfort, and they are made with a spray-skin technology in which a wear-resistant and UV-stable paint is shot into a mold to become the tough and rubbery skin. Drains in the floorboard make the Slingshot a true hose-it-out-and-go vehicle. Do, however, be careful cleaning the Slingshot LS because it has a backup camera, a media console and a six-speaker stereo, albeit a marine-grade one.

2015 Polaris Slingshot drive console

So, is the new Slingshot an answer to a question nobody asked? Viewed most callously, yes. But what’s wrong with creating an exciting pavement carver for two? It’s a great engineering exercise, and unlike, say, the Campagna T-Rex, the Slingshot is a backed by a huge network of 1,700 dealers in North America. That’s the kind of might that will expose this sporty three-wheeler to Polaris’ target audience, which includes adrenaline junkies who already own powersports products, folks who simply like to get noticed, and even older folks who may not have the balance they used to. And it’s these folks who will likely appreciate the Slingshot’s forged aluminum roll hoops, which bolt to the chassis and support five times the weight of the vehicle.

One final point: Polaris makes it clear that the Slingshot is a motorcycle, with no airbags. It’s not designed to meet automotive crash standards, and it’s not a step toward producing an automobile, says the company. Polaris also says that state laws apply in the US. In California, for instance, the Slingshot is considered a motorcycle. As such, the rider will need to wear a helmet and have a motorcycle endorsement on his license. In Canada, similarly, the Slingshot is considered a three-wheeled motorcycle.

When I think of three-wheelers, Morgans—built to avoid being taxed as cars in England—rank among the most successful. Will the Slingshot have such an enduring legacy? Probably not, but kudos to Polaris for having the guts to create such a wild and unexpected machine.

PRICE $19,999 (base), $23,999 (SL)
LENGTH 149.6 in.
WIDTH 77.6 in.
HEIGHT 51.9 in.
WHEELBASE 105.0 in.
FRONT TRACK 69.1 in.
ENGINE 2384cc dohc inline-4
HORSEPOWER 173 hp @ 6200 rpm
TORQUE 166 lb.-ft. @ 4700 rpm
TRANSMISSION Five-speed manual
BRAKES 11.7-in. vented rotors front and rear, ABS
STEERING rack & pinion, electric assist
FUEL CAPACITY 9.8 gallons

Windshield is optional on base model.

Look how low to the ground you sit.

Meaty rear tire can be lit up with ease, provided the traction control is off.

Note the super wide front track.

Hood tilts forward to reveal engine.

Note the negative camber of the front wheels.

Not exactly pretty from the side, but purposeful.

Not much in the way of rain protection.

Base Slingshot model starts at $19,999.

Stability is remarkably good.

Upmarket SL model costs $23,999.

People won't know what the Slingshot is when they approach it from behind.

View from the cockpit.

Looking down the hood.

SL is ready for action.

Base Slingshot, left, and SL.

Forged roll hoops are serious pieces, not decoration.

SL interior with tilt steering wheel.

Shift linkage ha medium-length throws, wide neutral gate.

Seats are comfortable, waterproof.

Dorsal detail.

Body removed to reveal tubular chassis and engine.

Disc brakes are used at all three wheels.

GM's 2.4-liter Ecotec 4-cylinder has aluminum block, good torque.

Transmission is an Aisin five-speed. No automatic is in the plans.

Battery in back helps with fore/aft balance.

Roll hoops bolt on, extend high up.

Classic double A-arm suspension, with a large front anti-roll bar.

GM engine is aft of the front axle line.

Slingshot looks elemental with body removed.

Sure would be nice to see some attractive exhaust headers.

Big anti-roll bar, in black, keeps Slingshot rear wheel flat on the ground.

Note the huge aluminum swingarm, Sachs damper and wide belt drive.

Frame is made of tubular steel with varying wall thicknesses.

Is the Slingshot a car or a bike? You tell us.