If the bike in these patent images looks vaguely familiar, that’s because it has the outline of Honda’s radical, shape-changing Riding Assist-e concept from back in 2017. This is a different way of looking at the concept of using electric motors to improve motorcycles in the future.
Riding Assist e was an impressive concept. It could change its wheelbase and steering-head angle electrically and, in its long-wheelbase version, it could balance itself, even while stationary, using a steering actuator to turn the wheel left or right. It could balance itself without the rider, using an electric motor. Interesting stuff, but it’s not clear how that ability would be a benefit to most riders.
This new design, while sharing the Riding Assist-e’s styling, has a completely different electric-drive system. Two separate patents cover the concept bike. The first patent relates to the two motors which drive the rear wheel. A second one is devoted to the front hub-mounted unit. By using computers and inertial measurement units to judge the bike’s angle and attitude, the torque distribution to these motors can be juggled to help its handling and performance.
Let’s start with the two motors at the rear. They’re mounted longitudinally and side by side just under the rider’s seat. They rotate in opposite directions, while each motor is directly connected to a drive shaft running along the bike’s swingarm to the rear wheel. On the face of it that seems unnecessary, but the two contrarotating motors and drive shafts are key to giving this bike cornering capabilities that couldn’t be achieved with more conventional designs.
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The direction in which the motors rotate on these Honda patents determines the way the bike will handle. They provide stability if they rotate in opposite directions. The bike will lean left when the motor on the left is rotated clockwise and the other in counterclockwise. When the motor on the right side rotates clockwise (and counterclockwise on the left), it helps to stand the bike out of corners. (Honda/)
The idea is to use motor torque to either lean the bike into a turn or to help it stand on its own when exiting a turn. From the rear, the motor on left rotates clockwise while the motor in the right is counterclockwise. When you apply more torque to the motor on the left, it will cause the bike’s torque reaction to try and lean left.
Honda’s patent suggests, for instance, that in a left-hand turn, the left motor will be given the most power on the way into the corner, helping the bike to tip in more rapidly. In the midcorner, both motors share power and torque equally to maintain stability. On the way out of the corner, it is the right motor that will have priority, creating a force to encourage the bike to get back into an upright position.
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View of the rear motors. (Honda/)
With Honda already looking at a number of riding-assist systems for the future, including steering assist, it’s clearly a way that street riders and novices could be helped, but also a system that might prove useful in a future world of high-performance electric bikes, even racebikes, by offering handling that couldn’t be achieved or aided using a conventional internal combustion engine.
The third electric motor is described in a second patent, and fits in the hub of the bike’s front wheel. It can be used to get more power down to the ground compared to a motorcycle with a single wheel drive. Honda sees this as a way to control wheelies.
Wheelie control systems have been around for a while, but they limit acceleration by reducing the power going to the rear wheels when the front wheel starts to lift. By using the torque-reaction idea and a motor inside the front hub, Honda thinks it’s possible to control a wheelie without cutting power, giving an outright improvement in acceleration.
Once again, the idea is to use the motor’s rotation to counter the pitching of the bike. To do this, the system detects when the wheel on the front has left the floor and continues to rise. It then reverses the front-wheel motor to counteract the movement. This means that the front wheel slows down and, if the front wheel continues to climb, it will stop spinning and start to reverse. The result is a force that pushes against the torque that’s trying to lift the front wheel.
The system recognizes when the front wheel has stopped lifting and is starting to return to Earth, cutting power or even returning it to forward rotation before it touches down. To avoid this, the system detects when the wheel has stopped lifting, and is about to return to the ground, cutting the power or even returning the wheel to forward rotation, before it touches the ground.