Motorcycles

New tilting 3-wheeler concept promises wild 52-degree lean angles

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Frank Knisley's Narrow Tilting Vehicle with Non-Tilting Wheels
Frank Knisley
The concept uses flat car tires rather than curved motorcycle tires, as the wheels themselves don't tilt relative to the pavement
Frank Knisley
The Narrow Tilting Vehicle with Non-Tilting Wheels
Frank Knisley
The whole vehicle cabin sits in a kind of cradle mechanism that can tilt to shift the cabin weight up to a whopping 52 degrees
Frank Knisley
The Narrow Tilting Vehicle with Non-Tilting Wheels prototype
Frank Knisley
The Narrow Tilting Vehicle with Non-Tilting Wheels prototype
Frank Knisley
The Narrow Tilting Vehicle with Non-Tilting Wheels
Frank Knisley
The whole vehicle cabin sits in a kind of cradle mechanism that can tilt to shift the cabin weight up to a whopping 52 degrees
Frank Knisley
The whole vehicle cabin sits in a kind of cradle mechanism that can tilt to shift the cabin weight up to a whopping 52 degrees
Frank Knisley
Frank Knisley's Narrow Tilting Vehicle with Non-Tilting Wheels
Frank Knisley
An early prototype of the NTVNTW
Frank Knisley
View gallery - 10 images

The absurdly named Narrow Tilting Vehicle with Non-Tilting Wheels (or NTVNTW) is a narrow track reverse trike that promises an amazing cornering experience with 52 degrees of lean and three flat car tires giving a huge grippy contact patch and excellent stability.

For the last century and a bit, cars and motorcycles have proven themselves to be affordable, simple transport options across the globe. But there's always been folks wondering – could the two platforms somehow be merged to join their strengths and minimize their weaknesses?

Cars, while relatively safe, comfortable and totally weatherproof, are much bigger than they need to be, at least 95 percent of the time. They get stuck in traffic. Motorcycles, while efficient, nimble, fun and able to dart through between lanes of traffic, leave the rider exposed to the weather, as well as much higher risks of injury in an accident.

For many years it has looked like somebody is going to make a big splash in the global transport market by coming up with a narrow-track vehicle not much wider than a motorcycle, that's fully enclosed and capable of leaning over in corners to keep its width to a minimum while still being stable in a corner.

We've covered a ton of concepts in the past, from the Sidam Xnovo to the Nissan Land Glider and the Terracraft. And while this one's essentially just a stack of patent drawings at the moment, it's notable for a couple of reasons.

The Narrow Tilting Vehicle with Non-Tilting Wheels prototype
Frank Knisley

The work of inventor Frank Knisley out of Ridge Manor, Florida, it's called the Narrow Tilting Vehicle with Non-Tilting Wheels, which breaks down to the catchy NTVNTW.

The NTVNTW is a platform that allows two, three or four wheel configurations, with Knisley's preferred first run being a three wheeler in a reverse trike style with two wheels at the front.

Notably, it uses flat car tires rather than curved motorcycle tires, as the wheels themselves don't tilt relative to the pavement. Instead, the whole vehicle cabin sits in a kind of cradle mechanism that can tilt to shift the cabin weight up to a whopping 52 degrees on either side in a corner or on slanted ground.

That's an impressive tilt angle - for reference, top level MotoGP riders on their incredibly sticky qualifying rubber rarely exceed a lean angle of 60 degrees in the turns, while dragging their knees and elbows across the track.

But those GP riders don't have the advantage of three fat, flat tires with their maximum contact patch in constant contact with the deck – and that's a significant stability boost. This thing has the potential to corner hard.

The whole vehicle cabin sits in a kind of cradle mechanism that can tilt to shift the cabin weight up to a whopping 52 degrees
Frank Knisley

The NTVNTW's cabin tilt is managed by hydraulic actuators that work in response to a group of sensors. As the sensors detect that the road surface angle is changing, or a cornering G-force is being applied, they move the cabin to the appropriate tilt level to maintain passenger comfort and neutralize the cornering forces. The road can slant up to that maximum of 52 degrees, and the cabin will remain vertical.

In this way it seems most closely related to the Terracraft tilting vehicle out of Texas, which also manages its tilt electronically and uses separate systems for steering and tilt. Mind you, the Terracraft team currently only has its vehicle tilting to 30 degrees, and its tilting front wheels are spaced wide enough to make it effectively take up a full car space in traffic.

Now that his patents are through, Knisley wants to work on a prototype vehicle to demonstrate the NTVNTW concept, but he sees it as being applicable to a range of transport modes up to and including public transport, with tiltable train carriages that allow faster rail cornering.

As a "man of meager means" he's looking to team up with other businesses and individuals that can help push the idea forward - particularly folks who can help with CAD design, parts, materials, machining and of course funding. We hope to see a prototype up and running soon - the proof of these ideas is always in the thrashing and we're always keen to help out with that. In the meantime, Knisley has left his contact details on some of the photos in our gallery, so feel free to contact him if you believe you can help.

View gallery - 10 images
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11 comments
Bob Stuart
I like the cheap, easy-rolling tires. The control system will have to anticipate the difference between a quick turn and and a quick lane change, and learn to countersteer to achieve a safely rapid roll rate. In running ball sports, the path of the footprints is wider than the path of the center of gravity to force quick turns, but we learn to calculate that as children, and are challenged to explain it to a computer, especially without advance notice of intent.
ezeflyer
He puts two wheels in the front and one in the back. This is the preferred system, not the reverse that is more prone to flip in a turn.
snave
I immediately see two rather substantial issues: 1: the overhang is lean dependent - you can foresee the driver encountering a declining radius corner, the vehicle increasing its lean - and the driver having his head taken off by an oncoming lorry... 2: any rapid-rate transition from left-right will see the cabin (and more importantly the riders head) utilise a convoluted rotational acceleration which will likely induce motion sickness in a good proportion of drivers/passengers
I suggest we rename the vehicle as the `Next Gen Vomit Comet`...
VirtualGathis
@snave - The issue you describe with a persons head being in the other lane is a problem motorcyclists all have to account for. When you are on the outside lane of the corner and following the outside, inside, outside route training calls for your head is in the oncoming lane if you corner too quickly. I've nearly been the lorry in your scenario a few times while coming around a corner to see a helmet in my lane... I ride as well so I can say it is an exhilarating feeling leaning deep into a corner, but to pull it off you have to account for the lean and imagine yourself laid sideways while on the bike, then leave that much room inside the corner. Otherwise you're likely to finish the corner shorter than you went in.
StWils
This should be a lot of fun on a closed, safe racetrack. On the open road this dangerous toy relieves surrounding traffic, like buses, of the inconvenience of actually running over the rider. The rider will put themselves under passing buses, cars, trucks, normal motorcycles, etc. This should be a real hit with anyone who been dying to have their heads just inches from the pavement whilst racing around curves at an unsafe speed.
Jason Catterall
Ahh, how I love thee, internet. So many positive comments.
pwndecaf
Yes, leaning a 2 wheeler also moves your head out into a different line than the wheels, but most riders, I would guess, do not corner that radically. My first thought was along the same as "snave" except I pictured my head suddenly encountering a roadside mailbox!
Mattiede
The tilting train idea has already been exploited:
https://en.wikipedia.org/wiki/Pendolino
and this innovative design can not improve the existing technology as far as I can see, as the overlap with onrushing trains on the other lane would be deleterious (like the bike-lorry example).
Bruce H. Anderson
I like it. A lot.
DavidGridley
Not quite a new idea.. Google the Carver One.