Source: Cycle World
That lever on the handlebar is something typically out of place on an electric motorcycle like Zero’s SR/F. (Zero/)Earlier this year, we revealed how Kymco plans to include an electronically simulated clutch and gearbox on upcoming electric motorcycles. Now it looks like Zero Motorcycles is thinking along similar lines, filing its own patent application for a faux clutch lever that modulates torque and regenerative braking to simulate the feeling and control an internal combustion engine-powered bike’s clutch.Although it would be easy to write this fake clutch off as a gimmick to appease stuck-in-the-past riders brought up on a diet of internal combustion engines, that would do the idea an injustice. After all, the clutch on an ICE bike is far more than simply an on/off switch to connect or disconnect drive to the rear wheel. It’s also a tool that we all tend to use to add finesse while riding, promoting an extra dimension of control. Whether it’s to modulate torque when you’re pulling away from standstill or working in harmony with downshifts to add a variable level of engine-braking, the clutch is an integral part of riding, and for those jumping on an electric bike for the first time it’s a control that’s particularly noticeable by its absence.Zero, like Kymco, appears to recognise the subtle control that a clutch offers and this new patent shows how the company wants to use the fingers of your left hand (left redundant on the company’s current range of bikes) as a constant control over the adjustable torque and regenerative braking of its electric motors. The company’s new patent application shows a completely normal-looking “clutch” lever and explains how it would be tied into the motor’s control electronics while giving familiar feedback to riders.Not a part typically associated with an electric motorcycle. (Zero/)In terms of feeling, the patent says: “To mimic the feel of a traditional clutch, the kinematic relationship among the left-hand control lever, the linkages, rotational sensor, yoke, etc., may be configured such that the driver of the vehicle initially feels a steep ramp-up in resistance when moving the left-hand control lever away from its rest position, followed by a peak dwell or plateau, then followed by a significant let-off, as the left-hand control lever approaches its fully retracted position. As the driver of the vehicle reduces pressure on the left-hand control lever it is urged toward its rest position by spring.” In other words it will be just what you expect if you’re used to a combustion engine bike.In operation, too, the results of using the lever will be familiar, even if it isn’t actually connecting or disconnecting drive via a set of clutch plates. The patent explains that: “By reducing the torque output by the motor, left-hand control lever mimics the operation and feel, e.g., slip, of a clutch of a multi-gear transmission present in motorcycles and other vehicles that are powered by internal combustion engines.”The patent documents show a Zero SR/F; will that model perhaps be the first to get the faux clutch if it does in fact make it to production? (Zero/)We don’t use the clutch lever purely to reduce engine torque though. Sometimes it’s used to access higher engine revs and get an engine into a stronger part of its powerband than the selected gear would allow without it. For instance, if you use the clutch to instigate a wheelie. Zero has also recognized that and envisages programming its faux clutch lever to respond in the same way by monitoring the speed with which the lever is moved as well as its position.The patent says: “For example, rapidly releasing the left-hand control lever from its fully engaged position may cause the controller to demand a short burst of torque from the motor that exceeds the torque demand indicated by the position of throttle, simulating or replicating the feel of ‘dropping the clutch’ in a vehicle that includes a multi-gear transmission and clutch.”The current Zero SR/F has a one-speed transmission and no clutch lever, typical of most electric motorcycles. (Zero Motorcycles/)The same ideas apply during deceleration, when the pseudo-clutch can be used to soften or harden the effect of the bike’s regenerative braking. The patent explains that “the controller causes the motor to operate as a generator to deliver electrical energy to battery, and brake the vehicle as a function of the rotational position, angular displacement, force and/or pressure applied to the left-hand control lever. Additionally, the controller may take into account the rate of change of the rotational position, angular displacement, force and/or pressure applied to the left-hand control lever in determining the amount of regenerative braking to be applied. For example, a rapid movement of the left-hand control lever may indicate that the driver of vehicle is demanding a very high level of regenerative braking, e.g., while making an emergency stop, whereas a slower movement of the left-hand control lever may indicate less drastic regenerative braking demands.”Kymco envisages combining its pseudo clutch with a simulated multispeed transmission operated by a familiar-looking set of foot controls. Zero’s patent leaves the door open for a similar approach and says that the system could be used alongside an automatic, clutchless gearbox but the document doesn’t make any mention of giving your left foot control over fake gear ratios. All the images in the document show the fake clutch fitted to Zero’s SR/F, suggesting that if it’s heading for production, that’s the model we’ll see it on first.
Full Text:
That lever on the handlebar is something typically out of place on an electric motorcycle like Zero’s SR/F. (Zero/)
Earlier this year, we revealed how Kymco plans to include an electronically simulated clutch and gearbox on upcoming electric motorcycles. Now it looks like Zero Motorcycles is thinking along similar lines, filing its own patent application for a faux clutch lever that modulates torque and regenerative braking to simulate the feeling and control an internal combustion engine-powered bike’s clutch.
Although it would be easy to write this fake clutch off as a gimmick to appease stuck-in-the-past riders brought up on a diet of internal combustion engines, that would do the idea an injustice. After all, the clutch on an ICE bike is far more than simply an on/off switch to connect or disconnect drive to the rear wheel. It’s also a tool that we all tend to use to add finesse while riding, promoting an extra dimension of control. Whether it’s to modulate torque when you’re pulling away from standstill or working in harmony with downshifts to add a variable level of engine-braking, the clutch is an integral part of riding, and for those jumping on an electric bike for the first time it’s a control that’s particularly noticeable by its absence.
Zero, like Kymco, appears to recognise the subtle control that a clutch offers and this new patent shows how the company wants to use the fingers of your left hand (left redundant on the company’s current range of bikes) as a constant control over the adjustable torque and regenerative braking of its electric motors. The company’s new patent application shows a completely normal-looking “clutch” lever and explains how it would be tied into the motor’s control electronics while giving familiar feedback to riders.
Not a part typically associated with an electric motorcycle. (Zero/)
In terms of feeling, the patent says: “To mimic the feel of a traditional clutch, the kinematic relationship among the left-hand control lever, the linkages, rotational sensor, yoke, etc., may be configured such that the driver of the vehicle initially feels a steep ramp-up in resistance when moving the left-hand control lever away from its rest position, followed by a peak dwell or plateau, then followed by a significant let-off, as the left-hand control lever approaches its fully retracted position. As the driver of the vehicle reduces pressure on the left-hand control lever it is urged toward its rest position by spring.” In other words it will be just what you expect if you’re used to a combustion engine bike.
In operation, too, the results of using the lever will be familiar, even if it isn’t actually connecting or disconnecting drive via a set of clutch plates. The patent explains that: “By reducing the torque output by the motor, left-hand control lever mimics the operation and feel, e.g., slip, of a clutch of a multi-gear transmission present in motorcycles and other vehicles that are powered by internal combustion engines.”
The patent documents show a Zero SR/F; will that model perhaps be the first to get the faux clutch if it does in fact make it to production? (Zero/)
We don’t use the clutch lever purely to reduce engine torque though. Sometimes it’s used to access higher engine revs and get an engine into a stronger part of its powerband than the selected gear would allow without it. For instance, if you use the clutch to instigate a wheelie. Zero has also recognized that and envisages programming its faux clutch lever to respond in the same way by monitoring the speed with which the lever is moved as well as its position.
The patent says: “For example, rapidly releasing the left-hand control lever from its fully engaged position may cause the controller to demand a short burst of torque from the motor that exceeds the torque demand indicated by the position of throttle, simulating or replicating the feel of ‘dropping the clutch’ in a vehicle that includes a multi-gear transmission and clutch.”
The current Zero SR/F has a one-speed transmission and no clutch lever, typical of most electric motorcycles. (Zero Motorcycles/)
The same ideas apply during deceleration, when the pseudo-clutch can be used to soften or harden the effect of the bike’s regenerative braking. The patent explains that “the controller causes the motor to operate as a generator to deliver electrical energy to battery, and brake the vehicle as a function of the rotational position, angular displacement, force and/or pressure applied to the left-hand control lever. Additionally, the controller may take into account the rate of change of the rotational position, angular displacement, force and/or pressure applied to the left-hand control lever in determining the amount of regenerative braking to be applied. For example, a rapid movement of the left-hand control lever may indicate that the driver of vehicle is demanding a very high level of regenerative braking, e.g., while making an emergency stop, whereas a slower movement of the left-hand control lever may indicate less drastic regenerative braking demands.”
Kymco envisages combining its pseudo clutch with a simulated multispeed transmission operated by a familiar-looking set of foot controls. Zero’s patent leaves the door open for a similar approach and says that the system could be used alongside an automatic, clutchless gearbox but the document doesn’t make any mention of giving your left foot control over fake gear ratios. All the images in the document show the fake clutch fitted to Zero’s SR/F, suggesting that if it’s heading for production, that’s the model we’ll see it on first.
