Bosch Gen4 (BES2) vs Bosch Gen4 (BES3)
Bosch Gen4 (BES2) vs Bosch Gen4 (BES3) – Key Differences Explained
Introduction to Bosch Gen4 Motors
When Bosch launched the Performance Line CX Gen4 motor in 2019, it set a new benchmark for e-bike performance: lighter, smaller, and more powerful than previous generations.
Originally, these Gen4 motors were built on the proven BES2 platform, known for its reliability, classic display systems, and compatibility with browser-based tuning solutions like the EBT Unlock Key.
In 2022, Bosch introduced a major evolution: the Smart System, also called BES3. Despite similar external designs, BES3 motors differ significantly in communication protocols, connectors, and tuning protection mechanisms.
Bosch Gen4 BES2 vs BES3: Full Comparison
| Feature | Bosch Gen4 (BES2) | Bosch Gen4 (BES3 Smart System) |
|---|---|---|
| Year Introduced | 2019 | 2022 |
| Displays | Intuvia, Purion, Kiox, older Nyon | Kiox 300, Intuvia 100, LED Remote |
| Motor Name | Performance Line CX Gen4 (BES2) | Performance Line CX Smart System (BES3) |
| Communication Protocol | Classic CAN-Bus | Smart System protocol (encrypted) |
| Tuning Possibility | Fully supported via EBT Unlock Key | Highly restricted (no browser tuning possible) |
| Service/Unlock Connection | Micro-USB at the display | Proprietary Smart System Service Port |
| Speed Sensor System | Classic spoke magnet sensor | Frame-integrated rim magnet (encrypted) |
| Firmware Updates | Moderate risk (EBT Unlock Key remains usable) | High risk (firmware lockdowns possible) |
How to Identify Your System (BES2 or BES3)
Bosch Gen4 (BES2)
- Round charging port near motor or frame
- Displays: Intuvia, Purion, classic Kiox, older Nyon
- USB service connection via Micro-USB
- Uses Bosch Diagnostic Tool via classic CAN-Bus
Bosch Gen4 (BES3 Smart System)
- Square charging port or waterproof Smart Connector
- Displays: Kiox 300, LED Remote, Intuvia 100
- No standard Micro-USB – special service ports required
- Updates and functions controlled via Bosch Flow App
Important: BES3 Smart System motors are not compatible with the EBT Unlock Key or other browser-based tuning solutions.
Traditional Spoke Magnet vs Smart System Rim Magnet
Bosch Gen4 BES2 motors use a simple spoke magnet system to measure speed – easily detectable and straightforward for tuning adjustments.
In contrast, Smart System BES3 models often feature a frame-integrated sensor combined with a rim magnet. This system introduces multiple challenges:
- Encrypted signal transmission
- Automatic recalibration after magnet tampering
- Harder to manipulate without sophisticated hardware
Why the EBT Unlock Key Works Perfectly with BES2 Motors
The EBT Unlock Key connects directly via USB to Bosch Gen4 BES2 systems. It enables safe and reversible unlocking — no mechanical modifications, no risk of damage, no trace after reset.
- 100% software-based unlocking
- Fully reversible at any time
- Future-proof for most firmware updates
- Works globally, from home – no dealer visits required
Summary Table: BES2 vs BES3
| Bosch Gen4 (BES2) | Bosch Gen4 (BES3 Smart System) | |
|---|---|---|
| Compatible with EBT Unlock Key | ✔ Yes | ✖ No |
| Micro-USB Service Connection | ✔ Yes | ✖ No |
| Speed Sensor Type | ✔ Spoke magnet | ✖ Rim magnet with encrypted signal |
| Risk of Firmware Lockdown | Low to moderate | High |
Conclusion: If you ride a Bosch Gen4 e-bike with the classic BES2 system, you can safely and effectively unlock its full potential using the EBT Unlock Key. If you have a Smart System (BES3), unlocking options are currently limited.
