Three-wheeled motorcycle by Jon Parsons

Not all of us believe that two wheels are adequate for a motorcycle. Jon Parsons certainly doesn’t. A UK-based chartered engineer who’s currently working as a designer with an aerospace company, Jon set up his own outfit, Dynamic Design Studio, back in 2006 in order to develop an in-line three-wheel motorcycle. “I have been riding motorcycles since I was 16 and have owned mopeds, touring bikes, sportsbikes, trials bikes, motocross bikes, enduro bikes and quads. I ride regularly and enjoy motorcycling in mainland Europe,” he says. We quite liked his 3-wheeled bike – it looks pretty interesting and by at the way it goes (see video above) seems to be quite a capable machine really.

We caught up with Jon for a quick chat to understand a bit more about how and why this 3-wheeled bike exists. Here’s what he had to say:

On how he came up with this idea for building a 3-wheeled motorcycle

Two events triggered me to think about 3x2x2 bikes. The first was while I was watching the first Weston-Super-Mare beach race. The motocross and enduro bikes really struggled to get enough grip to get over the largest dunes. I considered possible solutions like having more tyre contact with the sand to stop the wheel from ‘digging in’ and give the necessary grip. A wider tyre or even two wheels side by side (like a trike) would do this, but the resulting bike would not be able to lean into corners like a conventional bike. The answer appeared to be three wheels in a line and for this to work the wheels would need to be able to move up and down independently, and the rear wheel would need to be driven and steered.

The second event was when I was riding my Kawasaki ZX-9 around a corner in the wet when the front wheel hit a slippery patch, resulting in a slide then grip and the bike highsiding. I reasoned that if the bike had had a third steered wheel, it would still have had some steering, even when the front wheel hit the slippery patch and the rear wheel steering would have reduced the sudden lack of control until the front wheel had cleared the slippery patch.

On the dynamic benefits of having three wheels on a motorcycle

Dynamically, the in-line three wheel bike, with two wheel drive and two wheel steering (3x2x2 layout) has some inherent advantages – the driven middle and rear wheel give exceptional grip, improved acceleration over gravel and slippery surfaces, the additional steering at the rear helps push you around a corner and three wheels in a line reduces pitching moment over rough surfaces giving a smoother ride. Three tyres also help prevent the bike sinking on soft ground or marshy conditions, stopping is more controllable, especially when going down steep hills, with three wheel braking. And finally, the width of the 3x2x2 is narrower than a quad or trike and it can be leaned into corners.

On what’s his opinion of tilting trikes like the Piaggio MP3 and Carver One

I am impressed with the engineering that has gone into the MP3 and Carver where a lot of clever design has been used to make the concepts work and get the bike into production [but] the general problem with motorbikes with side by side wheel layouts, even the tilting versions, is an inherent roll instability caused when one of the front wheels hits a bump causing the bike to roll (tilt) to one side.

On the design and engineering challenges in building a bike with two driven wheels and where the rear wheel also helps with the steering

When I started designing 3x2x2 motorcycles in 1998, I wasn’t sure that it was possible to create a bike with three wheels, with two steered wheels, that would actually work. After all, the dynamics of a bicycle, with the requirement to balance, are more complex than that of car. My initial prototype built in 2007 was designed to prove 3x2x2 principles which it succeeded in doing.


The packaging of the extra parts with allowances for movement was challenging. Space was required for an extra wheel, swinging arm and suspension unit within a motorcycle that is not much longer than a conventional bike. The middle wheel required drive from the engine to it, drive from it to the rear wheel, a swinging arm from the frame to it and a swinging arm from it to the rear wheel.

On having a rear-wheel steering set-up on a motorcycle and how effective it really is

Rear wheel steering used on cars like the Nissan Skyline is more advanced than on my 3x2x2 design as it controlled by an electronic control system and the resultant car proved very effective on the racetrack. Rear wheel steering has been considered by others for use on two wheel bike, but would require a complex control system to make it work. Two wheel steering does work with the 3x2x2 layout, as can be seen in the videos, without having complex control systems.

On production possibilities and interest from mainstream manufacturers

The bike would be relatively straightforward to manufacture. The engine is standard and most of the parts are already designed for mass production. Those that aren’t could be redesigned for production without too much effort. There hasn’t been any interest from mainstream manufacturers, which is not surprising as they have their own future products based on what they know they can sell, sales potential of 3x2x2 bikes is an unknown. The mainstream manufactures would become interested if there was enough public interest.

On what kind of bikes would be best suited for the three-wheeled design

The current design is best suited to off-road and particularly over sand where it has a particular advantage with grip on loose surfaces. It would also be good for adventure bikes again where the extra grip is an advantage, combined with additional weight carrying ability. Ultimately the layout could even be used for sports bikes, where current engine technology can produce more power than a single wheel can handle, particularly in the wet.

Source Faster and Faster