The electric mountain bike landscape moves at breakneck speed—literally. Often, it’s hard to keep track of the near constant changes but, as riders, we’re the ones who benefit from these shifts. Recently, Bosch eBike Systems has delivered significant performance upgrades. The German engineering giant has not only listened, but delivered exactly what riders want from modern eMTBs.

Performance Line CX Upgrade

The Performance Line CX’s (BDU384Y) upgrade to 100 Newton metres (Nm) of torque, represents a substantial leap from the 85Nm standard. The upgraded system now delivers up to 750 watts of peak power while maintaining support levels of up to 400 percent of pedal input. This power enhancement becomes available through a software update for the latest Generation 5 motors—excellent news for current Bosch Performance Line CX Gen5 owners, as it essentially future-proofs your eMTB investment.

The best part? This upgrade can be done seamlessly via the Flow app, where you can customise power delivery characteristics to match your riding style and terrain preferences. Another key element of this upgrade is the introduction of the new eMTB+ mode, which leverages advanced algorithms to deliver power with what Bosch describes as “sensitive precision exactly when the rider needs it”. This represents a significant shift from simply providing more power, to providing smarter power distribution.

I tested this upgrade on a Santa Cruz Vala during a trip to Silvan Forest MTB Park (featured in this issue). First, the update was simple via the Flow app, and what immediately impressed me was its intuitive nature—neither under- nor over-compensating, just enhancing my riding. It adapted to my cadence and provided a boost when needed over tricky obstacles. Some other eMTB systems I’ve ridden rely heavily on higher cadence, especially with lightweight models, but that’s not the case here.

The clear standout for me was the new eMTB+ mode. I didn’t need to toggle between any other modes at all. The technical difference between eMTB and eMTB+ is 15Nm of torque and a maximum power output difference of 150W. This difference is definitely noticeable, though as a heavier rider the benefits might be more pronounced for me. Riding in eMTB+ mode, the power delivery felt intuitive, and I appreciated that extra assistance and traction when hitting steep inclines.

This isn’t simply about raw numbers—it’s about the intelligent delivery of power that adapts to the rider’s demands with superior sensitivity.

Kiox 400C

The Kiox 400C represents Bosch’s vision for the next generation of eBike displays, moving beyond basic readouts to become the command centre for modern eMTBs.

Designed for integration into the top tube rather than handlebar mounting, the Kiox 400C offers a cleaner cockpit aesthetic while maintaining full functionality. The display features customisable settings and automatic brightness adjustment, addressing one of the persistent complaints about previous generation displays that struggled in varying light conditions. Tactile buttons provide direct control, while the optional bar-mounted Mini Remote ensures riders can maintain proper hand positioning during technical sections.

Perhaps most significantly, the Kiox 400C includes an integrated USB-C port, finally addressing the evolving needs of modern riders who rely on multiple devices during extended rides. The system also supports navigation functions, transforming the display from a simple readout into a genuine trail companion.

On the trails, the Kiox 400C remained perfectly readable in all light conditions, and perhaps its best feature was the dynamic screen cycling. Essentially, various Bosch Smart System algorithms detect what you’re doing—like tackling a climb – and automatically display the most relevant screen for that situation. I appreciated the simplicity of having the display show only the most pertinent data, which helped me stay focused on the ride itself.

The sleek display’s integration into the top tube creates a much tidier cockpit, which is certainly appealing from both aesthetic and functional perspectives. And having the Kiox 400C’s ability to charge USB-C devices like my iPhone during a ride proved super handy—no more dead phone anxiety on longer adventures.

The Bigger Picture

Bosch has taken a measured approach to rolling out these innovations. The Performance Line CX software upgrades are available now, accessible through both dealer updates and the Flow app for end users. This dual-path approach ensures accessibility while maintaining professional oversight for riders who prefer dealer support. The Kiox 400C, while designed for 2026 model bikes, offers retrofit compatibility with select 2025 models from participating manufacturers. The backwards compatibility of both the Performance Line CX upgrade and Kiox 400C is a solid addition—especially valuable if you’ve recently purchased a Bosch-powered eMTB.

The timing is particularly significant as the eMTB market continues its rapid expansion, with riders increasingly demanding sophisticated performance. These developments signal a new maturity in motor technology, where software updates can deliver meaningful performance improvements and where display technology finally matches the premium level of the power systems they control.