Leaning in – Can Three Wheels Deliver Safe Motorcycling Thrills?

Motorcycles are fun, but dangerous. Aside from the fact that they possess absolutely no occupant safety features whatsoever, the have the rather unfortunate quality of being unable to stand up by themselves. Ask any 3-year-old learning to ride a bicycle what their biggest fear is, and you immediately understand the one inherent flaw of the motorcycle.

To stay upright, single-track vehicles, like motorcycles and bicycles, depend on the gyroscopic effects of wheels in motion and constant corrective steering inputs, which together result in an elegant balancing of forces. But once the wheels stop turning, if you don’t put a leg out, you will fall.

There is however, another solution.

One of the most unusual threads to emerge over the past decade of motorcycle design has been the return of the three-wheeler. A strange and unnatural looking vehicle at first glance, the three-wheeled motorized cycle has been with us almost from the beginning. The first car, Karl Benz’ Patent Motorwagen, was a three-wheeler. Bicycles in 1880’s Paris were fitted with two rear wheels to make them practical delivery vehicles for postal and grocery delivery. Motorcycles evolved from bicycles, starting about the same time, so people experimented with tricycle layouts right away.

The British Ariel 3 was an unlikely innovator. Terrible performance, quality, and a militant dealer network killed it but not before Honda noticed.
The British Ariel 3 was an unlikely innovator. Terrible performance, quality, and a militant dealer network killed it but not before Honda noticed.

Over the past century, the motorized tricycle has seen some modest success, largely as a low-speed, light commercial transport. Notable in the genus’ family history is the 1966 Ariel 3, a scooter fitted with two rear wheels that hinged with the rest of the chassis, allowing the scooter to lean in corners like a regular bike while the rear wheels remained horizontal. The Ariel 3 was a dismal failure as a product. But it did inspire Honda to buy a licence for the patented layout, beginning a leaning three wheel dynasty that continues to this day with the Honda Gyro, Japan’s takeout delivery vehicle of choice.

Throughout most of the 20th century, three-wheeled motorcycles remained a curio, typically nothing more than home-brewed or limited-production aftermarket conversion kits for conventional motorcycles by small companies, often using car parts on the rear end. In the late 1970’s, the All Terrain Cycle (ATC) hit the dirt with the promise of making the exploding motocross market safe for kids and grandpa, only to end with nearly 1,000 deaths, and the voluntary ban on ATC production by the major manufacturers.

Fun for the whole family. Until, you know, it isn't. 1982 Honda ATC advertising promises gentle off road adventure
Fun for the whole family. Until, you know, it isn’t. 1982 Honda ATC advertising promises gentle off-road adventure

The scandal of the ATC hinged on one inconvenient fact: three-wheeled vehicles are inherently unstable in parabolic (turning) motion. While the unassisted single-track motorcycle flops on its ear at a standstill, the laws of physics turn decidedly in their favour once they roll along, transforming the motorcycle into a paragon of predictable handling at virtually any speed. By contrast, vehicles with three points of contact are balanced at rest and low-speed, but become prone to tipping when loads change suddenly, such as high-speed cornering, especially downhill.

A three-wheeler in parabolic motion produces an undesirable combination of high torque forces on both the roll and yaw axis that are only too happy to overcome gravity and toss you into a ditch.  Sidecar riders know this, which is why they have to adopt counterbalancing body postures when cornering to prevent a roll over, particularly on inclines.  Even still, it takes little force for the inside wheel to “unstick”, or lose contact with the ground, which causes the center of the vehicles’ roll axis to move further to the outside of the turn, overloading the remaining two wheels.

Can-Am Spyder rider leaning into a corner, to counter the natural tendency of the fixed trike to roll out of the corner

Reverse trikes such as the Can-Am Spyder and Polaris Slingshot have some significant handling advantages over their ATC predecessors. Because they have two wheels up front, they generate substantially more grip when it is needed most, such as during changes in direction and under braking.

However, the sole rear wheel travels along the centre of the roll axis, and so can act as a pivot point during high energy turns, levering the inside wheel off the ground and flipping the vehicle. This is all mathematically predictable, so it can be engineered out of the vehicle’s performance envelope by using sophisticated electronic counter-measures.  But without them, a high-powered, high center of gravity three-wheeler is incapable of executing predictable, safe, high-speed turns without flipping. It is a reality of the laws of physics. The ATC was not unsafe, it just brought too many casual users too close to the edge of the performance envelope.

Perhaps that is why three-wheeled vehicles never took off anywhere. Why there are no three-wheeled Roman chariots, tricycle armored vehicles in Afghanistan, and why every three-wheeled car in history failed. Single-track vehicles enjoy an elegant relationship with the laws of physics that allow them to be used safely by anyone in a wide range of conditions, which is how children can pilot an old bicycle around a corner with little training. The ATC fiasco forced motorcycle manufacturers to stick with two and four wheels, the motocrosser and the ATV.

Coming to a battle space near you, the three wheeled/tracked fighting vehicle
Coming to a battle space near you, the three wheeled/tracked fighting vehicle

But the story of the three wheeled motorcycle didn’t end there.

An English inventor, Nick Shotter, spent 20 years and most of his money patenting a leaning four-wheeler he called the 4MC. During prototyping he approached Yamaha for technical support, who, according to Shotter, then tried to steal his technology. The European patent office said no, but Yamaha went ahead and presented the leaning four-wheel Tessaract in 2007 anyway.  The Japanese giant knew they were on to something, because when later Italy’s Piaggio launched the MP3 leaning three-wheeled scooter, they accelerated plans for their own leaning three-wheeler based on Tessaract technology, called the Tricity.  Peugeot produced their own, identical product. Patented to wazoo, Piaggio was unafraid to sue both Yamaha and Peugeot for infringement.

3w brothers

The MP3, Yamaha Tricity and Peugeot Metropolis are all configured the same way: two small diameter wheels in the front lean into corners independently, while the rear wheel follows the leaning front, but in the center line – just like on a conventional motorcycle. This layout provides incredible low traction stability (like say, in slippery conditions) and stability at rest (you can put your feet down at a stop, but you don’t have to), while maintaining all of the dynamic virtues of a single-track vehicle in motion. It turns as easily as a bicycle, and requires no special training.

The mission seemed accomplished, but then along came a Spyder.

Can-Am_Spyder_nose_action copy

Presented in 2007, Canada’s own Bombardier Recreational Products (BRP) launched the Can-Am Spyder RS (pictured above), a forward tricycle road vehicle powered by a version of the 1000cc Rotax twin from the spectacular Aprilia RSV Mille. It looked a lot like the snowmobiles that the company was famous for, and like them it did not lean when cornering. The rider sits astride the Spyder and operates handlebars as on a motorcycle, but all of the wheels are always perpendicular to the ground. The suspension is there to soak up the bumps, but does not lean the trike into corners like the MP3.

At this year’s Tokyo Motor Show, Honda threw its hat in the ring with the Neowing, a leaning three wheeler powered by a hybrid system including an inline four cylinder gasoline engine and a battery powered electric motor. Yamaha also upped their game with the conventionally powered MWT-850 (pictured, below), a leaning three wheeler billed as a “corning master”.


yamaha-03gen-x-e-03gen-f copyBoth the NeoWing and MWT-850 are, at present, concept models. But given the amount of innovation presented, production detailing like real world lighting, and the patents filed, it seems highly likely that the world’s largest motorcycle manufacturers will pursue this market. It makes sense, and suggests that the holy grail of motorcycling sensation and added safety have been discovered.

Spyder is not called a motorcycle by either its maker nor its huge user base. According to BRP, the company has sold over 100,000 of them as of May of last year, representing hundreds of millions of dollars in revenue for the company. With the introduction of last year’s F3 model, a sportier, foot-forward power-cruiser variant, sales are likely to continue to grow. “We are pleased with the platform as it is” said Can-Am’s Brian Manning, when asked if new entrants from the majors like the Honda Neowing and Yamaha MWT-850 might inspire BRP to try to lean in. “Those are different products.”

Honda Neowing leans in with hybrid drive train and the promise of super sport performance
Honda Neowing leans in with hybrid drive train and the promise of super sport performance

And maybe for good reason.  While the leaning Piaggio MP3, its in-house cousin the Gilera Fuoco, Yamaha Tricity and Peugeot Metropolis are different, their handling virtues do not seem to be resonating with consumers. None have seen a lot of market success in Europe or over here, although the Yamaha Tricity is gaining traction in Asia, according to the manufacturer. The BRP Spyder is, however, going gangbusters. It is not a motorcycle, and perhaps that is its strength. To those looking for open air excitement, it offers more comfort than safety, but enough risk to tempt them away from the convention of a convertible car.

Motorcyclists looking for the leaning sensation, but with a little more assurance, are not being tempted by the scooter derived MP3 and its imitators. Perhaps the bigger, bolder and more performance oriented Neowing and MWT-850 will attract them.

Evidence suggests that, for now at least, leaning is not what the marketplace is asking for.


  1. Just got back from a vacation in Bologna and Paris and the 3-wheelers are everywhere, along with the maxi-scooters. Very few of the vintage style Vespasian we see here in Canada.

  2. No mention of the Harley Servacar? It was actually quite popular as a service vehicle. Or the many trike conversions people were enamoured with in the 70’s, and (as I saw in Europe) still today. VW rear with a springer front end – what could go wrong?

  3. Spent a fair bit of time with the Piaggio MP3 and it was really quite a nice little ride. The 250cc version was say better than the bigger ones. Took it on one of our Sunday morning rides with the usual crew of hard core BMW GS riders and it didn’t lag behind at all. Cornering was just like on a motorcycle except it had more grip on iffy surfaces. Got quite good fuel economy too.

    If it came down to where I couldn’t swing a leg over a motorcycle, I could live with something like the MP3 quite easily. As for the Spyder? Had one of those for a week and I’d rather take the bus.

  4. BRP has done well withe the Spyder by providing a touring alternative to Harley dressers, Gold Wings and the like for older riders who may not be able to, or choose not to have to deal with a 2 wheeler.
    It would be interesting to see the buyer demographics – I’m thinking they are age 50+, perhaps with physical and/or mobility issues ?

    • A buddy of mine bought one, a guy never into motorcycles, when I asked him why the 3 wheeler, he said he found it like riding a big street going snowmobile. He doesn’t look at it as riding a bike but more like a sled or quad (minus a back wheel) and coming from that background it was instantly comfortable handling was intuitive. It kinda clicked in right about then why they may be popular among certain populations. Spyders are very popular in Quebec and there they have a healthy ATV and snowmobile recreation industry. Same with the southern states, I use to see a lot in the south, there they have healthy ATV following.

      or not, just my thoughts and observations.

      • Ivan

        I think you are exactly right. I had discussions with Spyder proponents about turn-steer versus counter-steer (i.e. Snowmobile/ATV vs. motorcycle/bicycle) and people from the former felt safer on Spyder than leaning a motorcycle. Like you said, it is a matter of perspective.

        I thought that BRP was wrong to deny that Spyder was a three-wheeled motorcycle, but in the end they were 100% correct, as the sales success proves. They are completely different animals for different people. I don’t like riding them, but then I am not the target customer.

        We should all be proud that a Canadian company, manufacturing in Canada, is as successful as it is, and committed to keeping production of an expensive, high profile machine like Spyder at home.

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