Bosch have just introduced a new software update for their Performance Line CX drive and other motor models. It increases maximum torque output by 10 Nm and improves the overall riding performance. We have already tested the new software update on the CX motor and compared it against the old software on two identical FOCUS JAM²s bikes. Read on to find out how the changes affect the overall performance of the motor, how new functions like ‘Extended Boost’ change the behaviour of the motor and whether the upgrade is worthwhile!
One year after launching their new Performance Line CX 2020, Bosch have released a new software update for all of their current ebike motors. According to the manufacturer, the latest update allows them to adapt the behaviour of each motor more specifically to its respective area of application. As a result, the characteristics of each motor, from the Cargo Line all the way to the classic Performance CX, should be more differentiated and provide optimised ride dynamics for where they are used. We’ve been testing the update for several weeks, on different bikes and in different conditions, and compared it against the old software.
We also compared the Bosch Performance Line CX, updated with the new software against other popular motors on the market. Head over to our big motor group test to find out how the Bosch fared against the competition from Brose, Shimano and more.
The new firmware delivers an extra 10 Nm torque
Since its launch in June 2019, Bosch have further refined the Performance Line CX motor’s firmware. With the latest update, the Performance Line CX should be even more refined, especially on sporty eMTBs. Without any changes in the hardware, the motor now delivers up to 85 Nm torque, up from 75 Nm and should, therefore, be more powerful, especially when pedalling at low cadences. However, both the peak power output and maximum support of 340% in Turbo and eMTB modes remain unchanged. While the increased torque should significantly influence the handling at low cadences, the main aim of the new update was to refine eMTB mode. Bosch have tuned their progressive mode even finer and trimmed it specifically for trail riding to ensure even more progressive power delivery, better modulation and a faster response. The new Extended Boost set-up was designed to provide an optimal amount of hysteresis to help the rider clear obstacles on technical climbs. Moreover, the useful cadence range has been extended to prevent the Performance Line CX from running out of steam when you accelerate to gain momentum before an obstacle. According to Bosch, the update shouldn’t affect the range or wear of the motor, because it only uses the peak 85 Nm torque for short periods.
Is the update worth it? Old vs. new
It’s not only the motor but also the bike and its components that have a huge influence on the overall performance of an ebike motor. An inefficient rear end, poor tire choice or heavy and thus sluggish wheels are only a few of the factors that can affect the perceived character of a motor. In order to minimise the impact of such factors and determine the differences between the old and new Bosch software, we compared them on two identical test platforms. The FOCUS JAM² 6.8 Nine is fitted with a Bosch Performance Line CX motor that is fed by an internal 625 Wh PowerTube battery. A Fox suspension chassis delivers 150 mm of travel. Due to the wet, slippery conditions, we decided to use a 29 x 2.6″ Schwalbe Magic Mary tire in the ADDIX Soft compound on the rear wheel of both bikes.
Can you feel the extra 10 Nm of the Bosch software update?
If you’re hoping to use the update to make your current motor a lot stronger, you’ll be disappointed. While the update increases the torque of the Bosch Performance Line CX by 10 Nm, in most riding scenarios you won’t even notice the difference, because both the maximum support of 340% and the peak power output remain unchanged. On the trail, you won’t notice the additional torque even when riding in the Turbo mode at higher cadences, because the motor reaches its maximum power at a lower torque. You’ll only notice the difference between the “old” and “new” software when pedalling at lower cadences, approximately below 70 rpm. On the trail this offers real advantages, especially on short climbs and when accelerating out of corners. Here the updated motor accelerates more willingly and responds more dynamically, even if you’re riding in the wrong gear at a low cadence.
With their software update, Bosch have made what was already the best progressive support mode on the market even better. All other manufacturers should use the Bosch eMTB mode as a reference.
However, for eMTBs, the real highlight of the software update isn’t the additional torque but the newly tuned eMTB mode. What was considered the best progressive support mode available on the market even before the update, has been made even better. As before, it automatically adapts the support level between Tour (140%) and Turbo (340%) modes depending on the pedal pressure applied. Up until now, the Turbo and eMTB modes were quite similar on start-up. The new Bosch software update results in more significant differentiation between the two modes. When setting off, eMTB mode responds even more discreetly and adapts itself to the rider’s input, making it more predictable and easier to control. This way, the increased torque can be modulated and used more sensitively, especially in slippery conditions: spinning rear tires, adieu! With the latest update, the Performance Line CX can be modulated even more intuitively with the sheer pedal pressure and always feels incredibly accurate in the progressive mode – both on steep climbs and on the trail. However, with very light riders eMTB mode responds a little too briskly, pushing a bit too abruptly on flat trails. In this case, it would be great to have the option of individualising the mode via an app to fine-tune its characteristics to each rider’s preferences.
On technical uphills, the Extended Boost feature helps you ride over ledges, steps and slippery roots. The sensor system detects the short acceleration burst before obstacles and delivers the appropriate amount of power combined with a long hysteresis. In other words, when you stop pedalling to avoid slamming the pedals into a rock or to lean forward to gain momentum, the motor keeps working and pushes you over the obstacle. Even without the software update, the Performance Line CX did this to an extent. However, support would suddenly drop off with a further pedal stroke required for the motor to resume its duties. Now, the latest software update overcomes this dead point brilliantly, providing support in the critical phase between the moment you stop pedalling at full hysteresis and the moment you resume pedalling with consistent motor support at and after passing the obstacle. The motor now also supports you better at higher cadences, for example when riding into a compression or accelerating before an obstacle. As a result, the support feels even more natural.
Is the new Bosch update compatible with my motor? If so, how can I install it?
The new software update only works with fourth-generation Bosch Performance Line CX motors, from model year 2020 onwards. There’s also a software update for other fourth-generation Bosch motors, i.e. the Cargo Line or Performance Line Speed, which offers the same torque increase but doesn’t include eMTB mode.
In typical Bosch fashion, only authorised dealers can make major system changes using special software. Over-the-air updates via smartphone are not yet available. Due to legal restrictions, S-pedelecs with the Performance Line Speed drive can only be updated by the bike manufacturer.
What does the new Bosch update cost and when will it be available?
Bosch provide the software update free of charge. That being said, only authorised dealers are allowed to install it on your eMTB. Whether and how much you’ll be charged depends on your local dealer. Installation takes around 15 minutes and if you’ve already booked a workshop slot for another reason, we’re sure your dealer will be happy to throw in the software update for free. The new motor software will be available from mid-July.
Since bike shops and dealers are currently very busy, we recommend booking your slot ASAP.
Bosch still has to do some homework
With the new firmware Bosch are further consolidating the leading position of the Performance Line CX motor in terms of ride dynamics and trail performance. Even before the update, eMTB mode had proved to be the best progressive support mode in our big motor group test – and it’s even better in its latest rendition. With the update, we would have loved to get individually customisable support levels, which, like with the Shimano and Specialized drives can be easily adjusted via a corresponding app. With the update, neither the hardware nor the integrability of the Performance Line CX into the overall system have changed. We’re curious to see when and how Bosch will improve aspects such as external speed sensors, rattling noises and exposed displays.
Bosch’s Cargo Line and Performance Line Speed get an update too
What’s better than torque? More torque! This is true especially when carrying heavy loads. However, this only makes sense if you can transfer the power to the road in a controlled manner. Thanks to the software update, the latest generation of Bosch Cargo Line motors now also churns out a maximum torque of 85 Nm. Above all, this helps prevent the bike from getting stuck on climbs when pedalling at low cadences. Moreover, with the new software update, the motor is significantly easier to modulate, more flexible and sportier – you can read all about it in our exclusive preview in DOWNTOWN Magazine, which will be released at the beginning of July. Before the update, the set-up was noticeably slower and oriented towards riding safety.
Performance Line Speed motors for S-pedelecs with a 45 km/h speed limit also get a 10 Nm torque boost with the update. Unfortunately, we haven’t been able to test this particular model. The update can only be performed by the bicycle manufacturer, who is responsible for homologating all changes to the bike.
More info about the Bosch software update at bosch-ebike.com
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Words: Photos: Robin Schmitt
