Disassemble Bosch "Performance Line CX" !! I learned the mechanism of the e-bike drive unit ♪

Bosch's new drive unit is here!!! It's the 2021 model "Performance Line CX". The Performance Line CX is a drive unit for e-MTB, but it's even more powerful than the 2020 model. The 2021 model Performance Line CX has a maximum torque of 85Nm, an increase of 10Nm, making it the "strongest torque" for an e-bike drive unit in Japan.

Bosch currently has two types of drive units for the Japanese market. One is the Active Line Plus, which operates quietly. The other is the Performance Line CX, which is compact and has a large torque and is for e-MTB, but this is a power-up.

In addition, a larger capacity in-tube battery "PowerTube 625" (capacity of about 625 Wh) has also appeared. Combined with the 2021 model Performance Line CX, it can travel 208km per charge. The 2021 model Performance Line CX-equipped e-MTB is already in sight, so I'm looking forward to seeing the finished bike.

In addition, Bosch will also introduce a battery system and a new color display as a 2021 model. You're leaning forward~!!!

As for the battery, the frame external type "PowerPack500" (capacity about 500Wh / cruising range 167km) and "PowerPack400" (about 400Wh / 135km). It has a larger capacity than the "PowerPack 300" (capacity of about 300 Wh) that has been distributed in Japan so far, but the size is the same and compatibility is also ant. If you replace the PowerPack300, the cruising range will increase♪

And the "DualBattery" system, which allows you to connect two batteries to the drive unit at the same time, is also available. For example, if you connect PowerTube625 and PowerPack500 to the 2021 model Performance Line CX, you can extend the cruising range per charge from 188km (Turbo mode) to 375km (Eco mode)!!!

New color display "Kiox" also appeared. The 1.9-inch high-resolution color display boasts a clear display and a wealth of information. It supports not only the running speed, remaining battery power and time, but also the watt (W) display of the rider's pedaling force. You can also display information from a Bluetooth-connected heart rate monitor (sold separately), or check ride information on the dedicated "eBike Connect app" by connecting to a smartphone via Bluetooth.

By the way, this Kiox display is also smart to detach from the handle mount. It is attached to the mount with a magnet and can be attached and detached with a light force. You can also prevent the drive unit from starting even if you connect it to an e-bike (drive unit) and connect another display of the same type. So, if you remove only the Kiox display and lock the e-bike during breaks, it will be a stronger anti-theft measure.

In my case, after test-riding the 2020 model Performance Line CX e-MTB, I fell in love with the drive unit, saying, "If I buy it next time, I'll buy a Performance Line CX e-MTB." . While there is enough torque, the followability to pedaling in trail riding is also perfect. The "eMTB mode" of the drive mode was very excellent.

The Performance Line CX has four assist modes: Eco mode for battery saving, Tour mode for balancing power and power saving, eMTB mode for MTB riding, and Turbo mode for maximum assist power. In eMTB mode, the assist force changes quadratically from Tour mode to Turbo mode depending on the force applied to the pedals.

You can finely control the power of the assist by adjusting the force with which you step on the pedal. Its naturalness makes you feel like "my MTB riding has improved". He/she shows very comfortable assist power.

The squid drive unit is powered up and appeared. I really have high hopes for the 2021 model Performance Line CX♪

…By the way, what is inside such a high-quality drive unit!? is. Then, I was blessed with a chance to see the contents♪ So, I will introduce the contents of the drive unit with photos and explanations below.

"Hello, this is Impress's e-bike department," I said to Bosch, and there was a drive unit on the desk!!! Mr. Yuichi Toyoda, Marketing, Bosch Electric Bicycle System Division, greeted me. He prepares a special tool and is willing to disassemble and show the contents. Mr. Toyoda joined Bosch after working on e-bike drive units for a domestic manufacturer. I'm also an engineer who knows a lot about various drive units. The motor on the right-hand side of the arrow rotates at about 3,000 revolutions per minute, but it is reduced by three gears. Ultimately, the force is transmitted to the crankshaft inside the bottom bracket and used as an assist force. The terminals that can be seen at the left arrow point are connected to the torque sensor and cadence sensor on the outer circumference of the bottom bracket. The torque sensor is a magnetostrictive type, and by applying pedaling force to the crankshaft, which is a magnetic body, the ease of passage of magnetic force around the shaft changes. It detects the induced electromotive force generated by electromagnetic induction in the detection coil, and calculates the pedaling force from the difference between the left and right induced electromotive force (using the magnetic Joule effect / Villari effect) This is the main board. As for the brain part of the drive unit, PowerPC is used for the processor, and it seems that it also leads to cost reduction related to drive unit development while efficiently performing firmware updates. The three holes indicated by the arrows are the connections for passing current to the motor.The three holes on the circuit board and the terminals from the motor are "crimped" to connect. In the case of drive units made in Japan, these parts are connected with connectors and cables, but in the case of Bosch, the terminals are crimped. This seems to be one of the company's automotive parts manufacturing technologies, and it seems that it contributes to the miniaturization and reliability improvement of the drive unit by eliminating connectors and cables.The gear inside the Performance Line CX (maximum torque 85Nm) is made of metal. . This is to keep the size of the parts to which force is applied to metal and minimize the size in order to accommodate the large torque in a compact size drive unit. We were able to reduce the size and weight, but the large torque applied to the metal gears makes some noise. This is the Active Line Plus (maximum torque 50Nm). The internal gear is made of resin. By using a relatively large resin gear, it can withstand the maximum torque and at the same time achieves a high level of quietness. It will be. In addition to the contents of the drive unit, I was able to hear interesting stories, so I would like to tell you about them in another time♪