Test / E-Bike: After years of dominance, a breath of fresh air is blowing through the e-bike market. New competitors are pushing into the spotlight with extremely powerful motors and innovative features, increasing the pace of development. However, the industry leader's response was swift: With the Performance Upgrade 2.0, Bosch is launching a massive upgrade package for existing Smart System drives. The raw figures sound promising: Up to 120 Nm of torque, a whopping 600 percent maximum support, clever software features, and with Garmin integration and a 12A fast charger, customer demands are being met. We thoroughly examined the update before its official rollout, both on the test bench and on the trail, and we'll determine whether it lives up to the hype.
The innovations at a glance: More power when it counts
Within its extensive portfolio of smart systems, Bosch aims to bridge the gap between the proven foundation and the increased demands of sporty e-mountain bikers with the Performance Upgrade 2.0. At the heart of the update, available from May 4, 2026, via the eBike Flow app, is a significant increase in performance. Riders can use the app to increase the maximum torque to up to 120 Nm. Peak support also sees a dramatic leap: Up to a speed of 15 km/h, the system now delivers 600 percent support in specific riding situations. In other words, the rider's pedaling power is multiplied sixfold.
According to the manufacturer, the premise behind this power boost is to deliver peak performance for challenging technical sections. The drive system constantly analyzes the riding situation and automatically releases full power precisely when the rider demands increased input at the pedals. Immediately after overcoming an obstacle, such as a steep section or a root-covered path, the system reduces power output back to an efficient level to minimize wear and tear and maximize range.
Fine-tuning the trail: The adjustable Extended Boost
Another feature of great interest to trail enthusiasts is the now adjustable Extended Boost. This dynamic overrun, which allows riders to confidently overcome obstacles without having to complete a full pedal stroke, can be customized from mid-2026. Using a new slider in the Flow app, the length of the overrun can be adjusted to individual preferences for each riding mode. The system reacts intelligently to pedal pressure and the riding situation: a gentle impulse generates a short boost for small steps, while a strong pedal stroke provides longer propulsion for high, sharp steps. Pedal strikes on rocky terrain should thus become a thing of the past.
Mechanical innovation via software: The drivetrain tensioner
Beyond the raw performance data, Bosch is introducing a feature unique to this mid-drive motor: the Drivetrain Tensioner. Also available from mid-2026 for the eMTB+ and Race modes, this feature aims to reduce pedal travel. Through intelligent software control, the motor engages the freewheel towards the rear wheel as soon as the chain loses tension. The result is virtually instantaneous power transmission when starting to pedal. This promises not only significantly more agile handling when accelerating out of tight corners, but also, especially in combination with the new torque peaks, drastically reduces wear on the chain, cassette, and freewheel.
Experimentation and data analysis: Trick Check and Live Data Interface
For the more playful riders, Bosch has integrated the new "Trick Check" function. The bike's sensors automatically detect maneuvers such as jumps, wheelies, manuals, and stoppies. Duration, height, distance, and angle are measured, confirmed with an audible signal, and visualized on the display for eight seconds. Personal bests can then be analyzed in the app.
In addition, Bosch is further opening up to third-party digital ecosystems. The new Live Data Interface allows users to connect their own GPS bike computers to the e-bike. This begins with an exclusive collaboration with Garmin. Compatible Edge devices (such as the 40 and 50 series) can display rider power, cadence, speed, and battery level in real time directly on the bike computer.
Hardware upgrade for your break: The 12A Fast Charger
With its 12A Fast Charger, Bosch is fulfilling a long-standing wish of many Bosch users. Thanks to modern GaN (gallium nitride) technology, the power supply generates significantly less heat at around 500 watts of charging power. The charger weighs less than one kilogram, is extremely compact, and charges batteries up to three times faster than the familiar 4A charger. A PowerTube 800 can be charged to 50 percent capacity in about an hour. Another positive aspect is that the charger is retrospectively compatible with all Bosch batteries in the smart system. The downside: the new charger won't be available until the end of the year, and its price has not yet been determined.
The Performance Upgrade 2.0 in practice and on the test bench
The data sheets sound excellent, but we put it to the test to see if it really works in practice. For our field test, we used the update on vehicles including a Focus SAM² and a Nicolai S18 Swift, and also took precise measurements on a test bench.
Thumbs up for the process: Anyone wanting to upgrade doesn't need to make a special trip to the dealer. The update is conveniently done via smartphone and the Flow app. It's important to know that the basic motor setup remains completely unchanged after the update. A current Performance Line CX motor will still deliver its familiar 85 Nm, 600 watts maximum power, and 340 percent support. The only change is the range of adjustment available in the app – you can now simply pull the sliders further to the right.
120 Nm: Much ado about nothing or the perfect trail ace?
Let's get to the biggest headline: the 120 Nm. Bosch is keeping the motor's absolute maximum power output at the already familiar 750 watts. To understand what this means, a brief explanation is worthwhile, as the relationship between torque and power is often misunderstood. Power (the actual work the bike does at the rear wheel) is always the product of torque and rotational speed (cadence). To achieve 750 watts, you can either use low torque at a very high pedaling speed – or high torque at a low cadence.
We visualized this relationship on the test bench. If you fix the power limit at 750 watts, but increase the torque in the app incrementally from 60 Nm to 85 Nm and then to 100 Nm, the curve clearly shows: the higher the torque, the sooner (i.e., at a lower cadence) the full power is available. In theory, this means that at 120 Nm, someone pedaling uphill at a leisurely 40 or 50 rpm will receive more power.
However, there is a major technical detail to note here: These 120 Nm stand for not permanent The sensors continuously calculate a "baseline" of the rider's average pedaling power during the ride. If the rider suddenly and abruptly pedals harder, for example before a step on an uphill climb, the system releases the 120 Nm as a dynamic boost.
Our measurements on the test bench (at a constant cadence of 60 rpm and a simulated rider power increase from 100 to 200 watts) impressively confirm this: The motor briefly surges upwards, similar to an overshoot, but then drops off very smoothly within a few seconds. This peak lasts only a few seconds. In practice, it feels as if there's a helper waiting at the steepest, most difficult section of the trail, giving you a short, powerful push, before immediately letting you pedal again yourself. Anyone expecting the feeling of a permanent shuttle pulling them up the mountain will be disappointed. It's an extremely precise, metered assistance exactly when you need it most. A nice-to-have feature, but not a riding experience that's worlds apart from how things were before.
600 percent support: A significant extra boost!
Much more noticeable than the brief torque peak, however, is the 600 percent support the system now offers. This effectively multiplies your own power output sixfold. Previously, the Bosch system topped out at around 400 percent. We also validated this value on the test bench. Since the Flow app unfortunately still uses cryptic levels from -5 to +5 instead of displaying absolute percentages, you have to experiment a bit. In Turbo mode, the setting "+0" corresponds to approximately 340 percent. At "+2," we hit the 400 percent mark exactly. Pushing the dial to "+5" brings us very close to the promised 600 percent on our test bench. The difference in practice is immense: the bike practically bursts with power when starting uphill.
However, there's a catch here too, which you need to be aware of: Bosch limits this enormous 600 percent assistance to a maximum speed of 15 km/h. If you exceed this speed, the system automatically reduces the assistance to 400 percent. This measure aligns with the recommendations of the German Bicycle Industry Association (ZIV). for voluntary self-limitation of performance.
On the trail, however, this implementation proves to be a minor drawback. While Bosch excels at all other control processes (such as temperature throttling, cutting off at 25 km/h, or the 120 Nm boost) with a wonderfully smooth, barely perceptible fade-out, the drop from 600 to 400 percent at exactly 15 km/h is quite abrupt. It's almost as if you're riding into a small, imaginary wall. It's nowhere near as drastic as the final cut-off at 25 km/h, but it's still a little disconcerting. A softer transition, perhaps starting gently at 14 km/h and ending at 16 km/h, would have been more appropriate for the otherwise extremely harmonious system.
Drivetrain Tensioner: The hidden gem?
A term that sounds cumbersome, but proves to be a real highlight in practice. Considering the amount of mechanical wear caused by the massive torque peaks in the drivetrain, this innovation makes perfect sense. Think of the freewheel in the rear wheel: It usually consists of delicate pawls. If you briefly stop pedaling (the freewheel clicks), these pawls have some play. Then, when you pedal again with full force and 120 Nm of motor support, the pawls slam into their teeth. An enormous strain.
The drivetrain tensioner, active in eMTB+ and Race modes, prevents this by maintaining tension on the chain. Sensors detect when the chain slack occurs. The motor then automatically rotates the front chainring enough to keep the drivetrain precisely tensioned all the way to the rear wheel, without actually driving the wheel.
The effects in testing are manifold: The often annoying "free play" at the pedal before technical uphill sections has completely disappeared. Power transmission is instantaneous, allowing for extremely precise modulation and pedal strokes. But the system brings another unexpected bonus: Depending on the drivetrain, the bike is noticeably quieter on the trail. Depending on the rear suspension system, the chainring rotates slightly during compression to maintain chain tension. The typical chain slap? Almost completely eliminated. However, the impact of this slight chain tension on the pure rear suspension performance requires further in-depth testing. Unfortunately, only users of the latest CX generation (BDU38) can benefit from this feature.
Finally: True Garmin integration and a fast charger
The wait is finally over: Bosch system data can now be integrated into the Garmin ecosystem. Instead of simply transmitting data via open ANT+ protocols like many competitors, Garmin has created its own controlled "Live Data Interface." This interface can be used with select Edge cycling computers starting today through the Garmin Beta program. By pairing the Edge device (40 series and above) in the Flow app like a drive component, the e-bike appears on the Garmin display. Speed, battery level (in percent), and, most importantly, the precise power output values from the internal power meter, as well as the cadence, are displayed flawlessly.
Perhaps the most tangible highlight, however, comes last: the new 12-amp fast charger. This new charger is small, weighs less than a kilogram, and charges batteries with an impressive 500 watts. The power cable is also detachable – a small detail that makes packing your backpack significantly easier. Unfortunately, this gem won't be available until the end of 2026, and Bosch is still keeping quiet about the price.
Conclusion: Competition is good for business!
With the Performance Upgrade 2.0, Bosch impressively demonstrates that it not only feels the pressure from competitors but can also constructively transform it into innovations. The increase to 120 Nm is, in practice, more of a subtle, lifeline in key sections than a general power monster. The 600 percent support, on the other hand, is phenomenal, even if the artificial cut-off at 15 km/h slightly disrupts the flow of riding.
The true stars of this software package are hidden in the details: The customizable Extended Boost allows for unparalleled fine-tuning, and the Drivetrain Tensioner is an innovative solution for more direct response and reduced wear. Rounded out by the Live Data Interface with Garmin integration and the prospect of the new 12A Fast Charger, Bosch has put together a package that significantly enhances the Smart System.