If there was any doubt Yamaha is devoting engineering resources to the idea of leaning multi wheel vehicles, this should erase those thoughts, it’s the OR2T, a 4 wheel leaning motorcycle concept, based on the Tesseract leaning 4 wheeler from 2007. It looks like a well developed test bed for finding out how it works on the road and getting feedback for further refinement.
At first glance, the word “heavy” comes to mind, but without actual numbers it’s hard to say and using advanced casting methods and light materials, it might be a lot lighter than it appears. If it works really well, the advantages may make this a practical motorcycle type vehicle, I say motorcycle type, because I’m thinking there are few places you could easily register a bike like this, what category would it fall into, and that’s unfortunate, because it could be a real game changer.
Though there were many hurdles to clear, in doing so, the engineers were able to confirm the many unique characteristics of the LMW (leaning multi wheel) configuration at the same time: a good feeling of stability at very low speeds, a solid feel when riding in crosswinds and usability when going over uneven road surfaces.
It certainly does look like it would be stable at low speeds and the video below shows the suspension responding to uneven road surfaces. The one place where we can’t see much detail is in the rear. I’m curious how that works.
For those of you who want to compare this to a standard motorcycle configuration, I think you’re missing the point, vehicles like this may pull riders from those bikes, but it’s really a new design only now becoming possible with current engineering and materials. Until you or I have the opportunity to ride one of these LMW concepts, let’s keep an open mind. I know I’d like to try one out on the highway and put it through the obvious uneven gravel road scenario to get a feel for an extra two wheels in low traction situations. I’m looking forward to seeing where this design goes.
Innis O'Rourke says
does countersteering still apply for LMW’s or would they have handling more like an ATV.
Boo Long says
They lean, so control by countersteering will be the same as any two wheeler.
Pushr0d says
“At first glance, the word “heavy” comes to mind,” Maybe to you, Paul!
“Jeezus!” was one of the first words to come to my mind. It looks like a Transformer that was interrupted halfway through morphing.
The machine (I hesitate to call it a ‘motorcycle’) looks to be purely an engineering exercise. Anything further would rapidly be filed in the ‘Just ’cause you can, doesn’t mean you should’ category.
I’d say no one would buy such a monstrosity, but then, there are a lot of Slingshots and Can-Am Spyders out there…
Paul Crowe says
Well, if you’re using movie analogies, how about “The Fly?” Two motorcycles go into the teleporter, but only one comes out. I mean, look at the first photo and tell me that doesn’t explain it. 😀
Maybe I’m getting mellow, but I find things like this quite interesting and I really would like to ride it.
Sarath says
I find it interesting that they went to a four wheel concept, but did not add natural stability removing the kick stand. That would have been awesome, at least from an engineering perspective. Four wheels for those who are afraid of hopping on a motorcycle, and leaning in corners to understand what the fuss is about. I guess, for it to be truly stable unassisted, the center of gravity will have to be lowered to reduce the scenario of the bike being toppled and a differential (or some other mechanism) applied to the rear wheels when stopped.
I agree about this being hideous, but as an engineering exercise, it’s pretty cool. In fact, I can see a modified variant of this, with added luggage capacity being used as an urban commuter. It can be what a lot of people want.
GenWaylaid says
Sarath,
That’s a good point about the c.g. With a track this narrow, it’s unclear whether the c.g. stays within the “box” defined by the contact patches when this bike is cornering. That might not seem important, but if traction is lost it means the difference between skidding and low-siding.
I wonder if the added traction and low-speed maneuverability of this concept could be put to better use off-road. If they can get the best features of an adventure bike and an ATV in one vehicle, there could be a real market for the idea.
Wave says
Based on the fact that it has a kickstand, it is very clear that the CG does go beyond the inboard tyres when the bike leans over. Otherwise, the kickstand wouldn’t be required.
In order to make a four-wheeler lean and counter-steer like a motorcycle, this is an essential requirement. If the wheels were far enough apart for it to be stable, there would be no force to make the bike lean. The whole reason that bikes lean into the corner is because they are “falling over,” but the centripetal acceleration of cornering keeps the bike from falling to the ground.
If you built this as wide as a conventional quad bike and gave the central chassis freedom to pivot relative to the axles, it would lean to the outside of a corner like a car. The only way to get a wide, inherently stable four-wheeled vehicle to lean into the corner is by applying an artificial force to make it do so. This can be done either with fancy suspension linkages controlled by steering input, or with electric/hydraulic/pneumatic actuators.
Wave says
I should actually clarify, I may be wrong about the above, but I am a mechanical engineer and this is my understanding of the situation. Here’s an example from the kneeslider:
http://thekneeslider.com/wesll-4-wheel-leaning-suspension-system/
I was looking at this design and almost started to doubt my statement that it was not possible to lean a stable four-wheeler without active force, but then I went to their website:
“The WST system is an active (smart) system. Components in the steering column measure an operator’s natural steering inputs and mass-shift. These measurements are transmitted to an ECU (Electronic Control Unit) which then affects control of a small hydraulic drive system to lean-assist the vehicle thereby substantially improving stability and control. The system is intrinsically safe. Electromechanical lean-assist, even at failure, cannot override operator control, which is insured via system geometry.”
So basically, the way I think it works, is that in the prototype quad shown on the Kneeslider, the suspension is just flexible and the rider has to use their own weight to lean the vehicle into the corner. The electronic system assists this weight transfer with actuators.
Wave says
With a sufficiently flexible suspension and high enough centre of gravity, you will be able to counter-steer a leaning four-wheeler. However, without an active system, you would also be able to lean it over to full lean angle even at very low speeds, e.g. getting your knee down while parking it. This looks embarrassing and would feel wrong, which is why all of the systems which have been attempted recently have active suspension to control the lean to the appropriate angle.
Fivespeed302 says
You mean you don’t knee slide into your parking space?!
Giolli Joker says
If I remember correctly the Piaggio Mp3 has a sort of “handbrake” that can be engaged to lock the tilting mechanism when the vehicle is not moving: it allows the rider to wait at the traffic light without having to put a foot down to balance.
A similar system could probably be easily implemented by Yamaha.
todd says
Years ago I had two Trail 90s, one with a sidecar attached. It didn’t take me very long to wonder what it would be like to tie the two bikes together with some links. Would I only need to register one of them?
Since the Yamaha contraption leans, it could still be counter steered to initiate turns. As far as whether it needs a differential – you’d only need to power one wheel. The wheels are so close together that the speed differential between them would be really low.
Ken Duplock says
This is the answer to a question that no one has yet asked.
Just because you can doesn’t mean you should.
Ax1464 says
I don’t understand this perspective. This bike is basically identical to a traditional two-wheeler except the front and rear wheels are doubled. Normal countersteering and leaning but with twice the traction. What’s the problem?
GenWaylaid says
I suppose the name OR2T stands for, “Of course you can Ride 2 at a Time!” That’s definitely the answer to a question no one ever asked about Yamaha’s motorcycles.
Fivespeed302 says
I call it the Oartootie.
Paul Crowe says
“Hooked on Phonics” makes reading easy. Just sound out the letters to form words. 🙂
Oli says
These ideas look good to designers, and might get bought by the risk averse with an ego to satisfy, but they don’t really solve any problems.
They have been building 3 and 4 wheel motorcycles for decades, but they never sell. The earliest one I’ve seen was in the UK motorcycle museum from 1927 or so.
Maybe they will gain some cult status if the idea is taken up by a TV show or something, but I can’t see the advantage over a specialist motorbike.
Tin Man says
Looks like the Chrysler Viper powered 4 wheel cycle that was built about 10 years ago. Its fun to watch these R+D vehicles built with unlimited budgets.
Paul Crowe says
The Tomahawk, the bike you’re referring to, was just for show and never a serious bike. This Yamaha effort seems very real and we should see something coming out of it whether in whole or in part.
Tin Man says
Well doing research on the the Tomahawk it appears 9 bikes were built and sold through Neiman Marcus for the pricey some of $500,000 each. While not legal for use as a motorcycle or as a car the Tomahawk has seen more miles than the Yamaha most likely ever will.
Paul Crowe says
Chrysler is a car company, you don’t see any motorcycles in their showrooms. The Tomahawk was a splashy marketing gimmick and a few deep pocket motorheads may have bought one to park in their garage next to the Lamborghini and AC Cobra to show their friends after dinner, but this Yamaha is being developed by a motorcycle company. I doubt it will go anywhere in its current form, but the technology could easily transfer to some other street legal model. I wouldn’t be too quick to dismiss it.
Tin Man says
They made more than one Tomahawk, 3 were produced if I recall. The things actually ran and still run. I believe they are owned by rich auto execs and just run on private roads and shows. I think Bob Lutz has one in his stable I think he once mentioned it in his article in Road+ Track.
norman hossack says
Its nice to see it in action, something I never managed to do. The fundamental here is that you never lose traction, there is always rubber on the road. I went down this path a long time ago but with a wider track I reasoned you would never have to put a foot down or use a stand. do I see familiar HOSSACK parts at the front of this YAMAHA?
Please look at hossack-design.com /QAR
Norman
Bill says
The bike’s of Rossi and Marquez have an child!
Brian says
I had a Piaggio MP3-400 for a couple of years, was great for my 75km each way commute, very comfortable, but what a bugger to park in a restricted space, like a car park for instance. It was so front end heavy and heavy generally. Despite two front wheels it can still fall over, and at 250kg (550lb) one (this one anyway at 65kg) is left with the embarrassment of having to shout out for help. I’m glad I got to use the bike, but wouldn’t buy one again!
Simon Evans says
Brian has hit the nail on the head. The added traction is completely nullified by the extra weight and steering inertia – unless you intervene with artificial aids, which then doesn’t permit taking full advantage of the increased traction as you’ve killed the precious `feel`.
And again, Yamaha have had to utilise a high CG to get The Thing to turn. This is all wrong for a leaning double track vehicle.
They are STILL applying single-track thinking, and then engineering around it, which convinces me that this is a vanity project, not a worthwhile prototype to later improve the breed.
Thinking practically, you’d pay twice as much for something which now costs more to service, is heavier on tyres (both front and rear being offset to the central axis so slippage wear on the shoulder will create cupping and uneven off-profile wear – real roads are cambered!) and when they need replacing it will be two at a time for the front and rear. Even if the overall wear were the same, it would cost a fortune in tyres. And accelerate at about the same rate as something commuterish. It might brake a bit better in a straight line, but I’d be interested to see how the geometry affects braking while leaning – my guess is rapid transition from under- to over-steer and diminished stability in-corner.
When designed properly a leaning narrow-track vehicle can have systemic advantages over a single track vehicle.
This ain’t it.
Fivespeed302 says
My god that may be the ugliest headlight/front “fairing” I’ve ever seen!
Ratter says
Four wheels disqualifies it from being a “motorcycle”. Cannot guess how this would affect licensing or operator requirements. Wisconsin state law:
(32) “Motorcycle†means a motor vehicle, excluding a tractor,
an all−terrain vehicle, or a utility terrain vehicle, which is
capable of speeds in excess of 30 miles per hour with a 150−pound
rider on a dry, level, hard surface with no wind, with a power
source as an integral part of the vehicle, and which meets the conditions
under par. (a) or (b):
(a) Type 1 is a motor vehicle which meets either of the following
conditions:
1. Is designed and built with 2 wheels in tandem and a seat for
the operator, and may be modified to have no more than 3 wheels
by attaching a sidecar to one side of the wheels in tandem without
changing the location of the power source.
2. Is designed and built to have no more than 3 wheels, seating
for the operator and no more than 3 passengers, and does not have
the operator area enclosed.
(b) Type 2 is a motor vehicle designed and built to have at least
3 wheels in contact with the ground, a curb weight of less than
1,500 pounds, and a passenger and operator area with sides permanently
enclosed with rigid construction and a top which may be
convertible.