Believe it or not, it was back in 2019 when the current 4th generation Bosch Performance Line CX motor was introduced. Given how rapidly electric mountain bike technology is evolving, five years of service is an incredible feat. Indeed it’s a real testament to the CX motor, which has managed to fend off most of its competitors while earning an enviable reputation for its power, responsiveness and overall reliability.
Of course the Bosch Performance Line CX motor hasn’t been perfect. It’s not exactly the smallest drive unit out there, and it’s suffered from a well-documented rattle that occurs when coasting over rough ground. Battery tech has also evolved considerably over the past few years, and so too has consumer expectations when it comes to the e-MTB user interface and customisability.
As well as tackling some of the downsides of the Gen 4 drive unit, Bosch is aiming to bring a whole bunch of new features and refinements to its full-powered motor. Here we’ll be diving into the details behind the new system, which we expect you’ll be seeing on a lot of e-MTBs for 2025.
Big news e-MTB fans – the Bosch Performance Line CX Gen 5 motor has finally been unveiled!
An overview of the Bosch Performance Line CX Gen 5 motor
From the outside, there doesn’t appear to be any obvious points of difference with the new Bosch Performance Line CX Gen 5 motor. The overall shape and size is pretty similar, and it’s said to produce the same 85Nm and 600W of peak power output as the current Gen 4 drive unit.
There is a small weight drop (2.8kg vs 2.9kg) thanks to the move to a magnesium housing. The CX Gen 5 motor also moves to a similar two-bolt mounting system as the lightweight SX motor. This makes for simpler installation and removal, and presumably it makes it easier for bike manufacturers to design their frame around.
More importantly, the gearbox design has been updated over the Gen 4 motor. Bosch claims this has eliminated the clacking noise, making for a blissfully silent ride on the descents. For many riders who are bothered by that noise, this will be the news they’ve been waiting for.
The CX Gen 5 motor employs a magnesium casing to reduce weight, and it adopts the two-bolt mounting system first shown on the SX motor.
Smarter sensors
There’s a bit more to it than just a gearbox update though. Bosch says it’s re-engineered the sensor technology in the CX Gen 5 motor to make it more responsive and better at understanding what the rider and terrain are doing.
Of course there are torque sensors and a high-resolution cadence sensor, which are claimed to measure pedal inputs at 1,000 times per second. The motor is also able to detect pitch and vibrations thanks to its inertial sensors, so it knows the difference between a smooth uphill bike path and a technical singletrack pinch-climb. Using this information along with measuring the rider’s power input and current speed, it changes how it delivers power to the rear wheel accordingly.
Thanks to its improved smarts, the CX Gen 5 motor incorporates a new Hill Start Assist function that aims to provide better rear-wheel grip when starting on a steep slope. The Walk Assist has also been updated so that the pushing speed is more accurately matched to your walking speed.
The Bosch Performance Line CX Gen 5 motor is said to be smarter than its predecessor, with new sensors that can better detect what the rider and trail are doing.
Bosch PowerTube 600Wh & 800Wh batteries
To go along with the Bosch Performance Line CX Gen 5 motor there are two new batteries; the PowerTube 600 and PowerTube 800.
These utilise the same updated cells as the CompactTube 400 battery that debuted with the lightweight SX motor last year. They feature a higher energy density, which simply means more watt-hours at a lower weight;
Bosch PowerTube 600 Battery – 3kg
Bosch PowerTube 800 Battery – 3.9kg
To put that into perspective, the new PowerTube 800 is quite a bit lighter than the old PowerTube 750 battery (3.9kg vs 4.4kg) despite offering greater capacity. Nice!
Bosch has also updated the alloy casings, which feature a different width and length between the 600 and 800Wh batteries. This means that bike brands will largely need to commit to one or the other, though we do know of one new e-MTB coming that will be able to accept either size battery.
It’s worth noting that each of the new batteries is capable of being paired with the PowerMore 250 range extender. So regardless of which size comes fitted in the downtube of your e-MTB, you have the option of increasing the capacity by purchasing the range extender should you need it.
The new Bosch Purion 400 display looks pretty similar to those from Shimano.
There’s a new Purion 400 display
Bosch is also rolling out a new Purion 400 display alongside the CX Gen 5 motor. This joins the minimalistic System Controller and data-rich Kiox 300 display, effectively striking a middle ground between the two.
Featuring a 1.6in screen, the Purion 400 bears a close resemblance to Shimano’s EM800 display. It’s designed to mount in a similar location on the handlebar and adjacent to the stem, where it’ll provide key data including your current speed, riding distance, power, cadence, range and battery status.
Otherwise the Bosch Performance Line CX Gen 5 motor offers the same assist modes, with up to seven to choose from including Eco, Tour+, eMTB and Turbo. Riders will be able to customise these and tune the motor’s output using the Bosch eBike Flow app, which has received some noteworthy updates over the past 12 months to improve overall functionality.
For e-MTB riders and racers, the Bosch ABS Pro system is claimed to improve traction.
Updated Bosch ABS Pro
Lastly, there have been updates to Bosch’s ABS system with the introduction of ABS Pro. This has been designed specifically for e-MTB use and high-performance braking systems, and is claimed to allow for hard braking with less chance of skidding.
Bosch says it developed the ABS Pro system in conjunction with eMTB racers, which lead it to offer two different modes. ABS Trail Pro is said to be for regular e-MTB use where the rider is looking for maximum grip. The system incorporates something called ‘rear wheel lift control’, which reduces the chance of the rear tyre from bouncing off the ground during really hard braking.
For more advanced riders, the ABS Race mode removes this function in order to allow for stoppies when negotiating a tight hairpin, a scenario that is quite common during European enduro races.
The 2025 Norco Sight VLT CX is one of the first e-MTBs to be released with the new Gen 5 motor.
What bikes will be coming with the new Bosch CX Gen 5 motor?
We know of four different e-MTBs that will be launching with the new Bosch Performance Line CX Gen 5 motor. However, at the time of embargo, it’s only the Norco Sight VLT CX that we can mention. You’ll hear about the others very soon though!
Given the purported improvements, we can imagine there’ll be quite a few brands rolling out updated 2025 models with the new CX Gen 5 motor. We’ll aim to add those bikes here as they’re unveiled to public.
We expect there’ll be a load of brands unveiling new e-MTB models with the CX Gen 5 motor over the coming weeks.
Flow’s Take
The Bosch Performance Line CX Gen 5 motor doesn’t exactly represent a revolution over the Gen 4 motor we’ve come to know and love over the past five years, but then the German company has always focussed on reliability and refinement over jaw-dropping technological innovations. It’s for that reason why the Gen 4 motor has long been regarded as the leader in the full-powered e-MTB market, and it certainly puts Bosch in good stead to roll out its successor.
There are plenty of welcome updates too, with the quieter gearbox being particularly appealing. Combined with the improved sensors, lighter batteries and Purion 400 display, there is a lot to get excited about in the next-generation CX system.
Will it be enough to stave off the competition? New players like DJI and ZF are looking to disrupt the market in a big way, and we understand that Shimano has been testing new prototype hardware and firmware with the Yeti EDR race development team. SRAM has plenty to build on with its Powertrain, Specialized is due for an update with the Levo and its Brose-manufactured 2.2 motor, and we anticipate both Fazua and TQ will be making a jump into the full-power market at some point in the near future.
Indeed the pressure on Bosch is growing even greater, and we look forward to swinging a leg over an e-MTB with the new Bosch Performance Line CX Gen 5 motor to see if it’s worthy of keeping its crown.
Does Bosch have what it takes to fend off the competition? We look forward to experiencing the new CX Gen 5 motor ourselves to find out!
The post First Look | The new Bosch Performance Line CX Gen 5 motor appeared first on Flow Mountain Bike.
Believe it or not, it was back in 2019 when the current 4th generation Bosch Performance Line CX motor was introduced. Given how rapidly electric mountain bike technology is evolving, five years of service is an incredible feat. Indeed it’s a real testament to the CX motor, which has managed to fend off most of
The post First Look | The new Bosch Performance Line CX Gen 5 motor appeared first on Flow Mountain Bike. Read More Flow Mountain Bike
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