German tier 1 supplier Vitesco Technologies aims to advance the hybridisation of motorcycles and is showcasing the next development stage of a hybrid motorcycle with an additional electric drive, which it says significantly reduces CO2 emissions.
The prototype motorcycle and components are being showcased at EICMA 2022, the world’s largest trade annual show for two-wheelers.
The concept hybrid motorcycle includes a fully electric start-up without clutch actuation and an electric reverse gear. The concept is designed for motorcycles with a displacement of over 125cc and comprises a 48-volt electric motor, an automated manual gearbox and, as the ‘control centre’, a Powertrain Domain Control Unit (PDCU), the so-called Master Controller.
Vitesco Technologies had first presented the development stage of the hybrid concept at EICMA last year.
Torsten Bellon, head of the 2-Wheeler & Powersports product line at Vitesco Technologies said, “For medium-sized and large motorcycles with combustion engines, we expect that future exhaust emission limits can only be met by using hybridisation in combination with an automated manual transmission.”
“With this aim in mind, our development focus was initially entirely on reducing CO2. Over the past twelve months, we have adapted the technology, which originated in the passenger car segment, to meet the specific requirements of motorcycles, developing many additional functions that are only possible with an electrified powertrain. During our development work, it became increasingly clear that our hybrid concept opens up completely new possibilities for making motorcycling more dynamic, more comfortable and safer. We exploited these options and are now in a position to support manufacturers with an easy-to-implement, low-cost and highly effective system,” he added.
The electric engine of the hybrid concept is a standard belt-driven starter generator from the passenger car sector, which Vitesco Technologies has been using 48-volt hybridisation since 2016. The Master Controller, also from the passenger car segment, is responsible for the control strategy, which is particularly demanding in hybrid systems. It controls the 48-volt engine, communicates with the M4C engine control unit of the combustion engine and decides when to switch to electric drive, when to drive ‘conventionally’ and when to use a combination of both drive types.
The automated Smart Transmission is equipped with a centrifugal clutch and an intelligent actuator. While driving, the Master Controller can change gears independently without clutch actuation at the best time for economic fuel consumption.
The 12 kW electric motor and a removable 1.5 kWh battery enable the concept to travel a distance of up to 30km and at a speed of up to 60km per hour in pure electric mode. The combustion engine in the hybrid concept has an output of 32 kW and a top speed of 160km per hour. In this configuration and in combination with the current WMTC (World Motorcycle Test Cycle) the hybrid concept reduces the motorbike’s CO2 emissions by up to 75 percent. The system increases the overall weight by only approximate 20kg. At 170kg, the concept is lighter than a fully electric motorcycle with a similar performance – and is also considerably cheaper.
Unlike in the passenger car sector, where hybridisation can be significantly more expensive, Vitesco Technologies’ motorcycle system can already be integrated at an additional average system cost of less than 1,000 euro (Rs 81,600).
Christophe Genin, head of the hybrid concept project, Vitesco Technologies states for instance the challenge for novice riders who have switched to a motorcycle is operating the clutch.
“This was one of the things that motivated us to develop the electric start-up function. This means that when travelling at a speed of up to 20km per hour, clutch operation and the risk of stalling are no longer an issue, increasing both comfort and safety, especially in stop-and-go traffic.”
Electric starting is enabled by the electric motor and the smart transmission. “But like all the new functions of our hybrid motorcycle, developing the corresponding control strategy for the Master Controller was the key aspect here,” added Genin.
Best of both worlds
The drive responds more agilely thanks to the instantly available e-power. Secondly, the electric motor provides impressive power delivery, especially in the lower engine speed range: Thanks to the additional e-boost, the torque reached here is up to 60 Nm (maximum torque without e-assist: 37 Nm at 7,000 rpm).
This the company says means that the medium-sized hybrid motorcycle (displacement: 401cc) can generate more punch than a conventional bike with a 1000cc engine. And thanks to the powerful electric drive, the thrust is available not just for a few seconds, but over minutes.
In addition to purely electric start-up, the electric drive also allows the vehicle to be driven in reverse. This convenient function is extremely helpful, especially in tight or downhill parking spaces. The hybrid concept also offers a number of other advantages. For example, the electric motor can compensate for the short torque interruption that occurs during gear changes to keep the wheel torque as constant as possible when shifting up and down.
The generator function of the electric motor, used to charge the battery, can be used as an additional engine brake so that the mechanical rear brake is only needed if the motorcyclist needs to decelerate sharply.
In addition, the hybrid concept’s energy management can be linked to the navigation system to ensure that the battery is fully charged, for instance before entering a city or before a long hill climb (so-called predictive ride function). A hybrid motorcycle also offers great flexibility in route planning: At around 260km, the Vitesco Technologies concept can provide a greater range than comparable electric motorcycles – and can be swiftly refuelled at any fuel station.