Piaggio brought leaning three-wheelers into the industry mainstream with its MP3 scooter in 2006, with similar vehicles later introduced by Quadro 350D in 2012 and the Peugeot Metropolis in 2013. More recently, Yamaha released the Tricity as the first in a new family of leaning multi-wheel vehicles.
If newly-published patent filings are an indication, it looks like Honda is the latest manufacturer to develop a leaning trike. The Japanese Patent Office published three patent applications from Honda related to a leaning trike with a pair of front wheels.
Unlike the examples above, Honda’s design will not be a scooter. Instead, the patent diagrams illustrate a motorcycle using a similar-looking chassis and engine as Honda’s NC700S. The NC platform has proved to be fairly versatile so far, lending itself to the CTX700 and NM4, so it’s no surprise it may once again be called into duty for this trike.
The tilting mechanism is a variation of the parallelogram suspension design similar to those on the Yamaha and Piaggio trikes. The term parallelogram isn’t actually accurate in Honda’s design as the left and right sides (29L and 29R in the diagram below) aren’t parallel but are slightly farther apart at the bottom.
Instead of two solid lateral arms (the top and bottom of the parallelogram), Honda’s design uses a single upper arm and separate arms (26L and 26R) extending left and right from a central subframe (23) that runs up the middle of the parallelogram. The left and right arms are offset when the vehicle is tilted, and the two sides (29L and 29R) thus tilt at two different angles when the vehicle is leaned over.
The sides 29L and 29R each connect to one of the front wheels. As with the MP3 and Tricity, the suspension components are kept between the wheels. Yamaha uses a cantilevered fork with two downtubes on either side of the wheel axis and Piaggio opted for a leading link system. Honda’s design uses a trailing link suspension with arms going down from the tilt mechanism to a link in front of the wheel axis.
Of course, we have to remember these are just patents that may never result in a production model. The finished product (if there is one) may not look exactly the same as the diagram, though Honda’s choice to use the NC700S as a model would at least indicate the direction the designers are considering.