Bosch CX 4th GEN Mountain Bike Motor

Bosch CX 4th Gen – Here’s What to Expect After a Year of Riding

The Bosch CX 4th Gen motor is Bosch’s latest product on the Performance Line CX. Considering the company’s reputation. It is somewhat of a surprise that this motor offers excellent features for e-bikers. It leads us to the question – what can you expect on the 4th Gen Bosch CX after a year of use?

The Bosch CX Gen 4 will still offer excellent torque and power even after a year of riding. The motor will still let you accelerate fast on trails, especially at low cadences. Its long battery life will still allow bikers to ride for a long time.

Bosch CX 4th Gen

Electric bikes are becoming mainstream on the streets and trails right now. And when it comes to e-bikes, Bosch is among the market leaders. The reason is that the brand invested heavily in the electric biking industry to bring the best products for bikers.

Additionally, Bosch continues to innovate and provide excellent service to the market.

Moreover, the Bosch CX 4th Gen is the latest product offered by the brand.

RIDE e MTB Pro Tip: With eBikes growing in popularity learning all the terms and definitions can be a bit overwhelming. Let me help with this comprehensive glossary. 👉 eBike Glossary

2020 Bosch Gen 4 Performance Line CX Motor

This motor is the most significant change Bosch has made in its product lineup since 2016.

The Performance Line CX Gen 4 is the brand’s most powerful motor, nearly 50 percent smaller. However, it comes in 25 percent lighter than the previous version.

The additional assistance offered by the 4th Gen Bosch CX provides an excellent riding experience. The weight is reduced by a kilo, making the motor more discreet than ever.

Moreover, the previous version of the 4th Gen Bosch CX consists of a small sprocket intended for the front chainring. On the other hand, the new motor fixed this issue, making the rider’s pedaling power better.

What To Expect from A One-Year-Old Gen 4 Bosch CX

1.    Excellent Torque

The Bosch CX 4th Gen’s torque was increased to 85Nm, making it more potent than its predecessors. This torque increase poses a noticeable effect on riding behavior.

E-bikes with this motor system accelerate faster, especially at low cadences. The torque can even make uphill starts faster.

So, even after years of riding the 4th Gen Bosch CX, you can still ride your e-MTB reasonably easily.

2. Natural Riding Strength

The 4th generation Bosch CX boasts perfectly controlled support even after using it for a year. It has powerful 32-bit support that processes sensor signals at high speeds.

3. Extended Boost

The Extended Boost is a unique feature that allows bikers to ride smoothly over rough trails. With this function, you can maneuver with ease and agility on rugged terrains.

4. Thermal Stability

The Bosch CX 4th Gen is perfect for extreme loads. Even after a year, the drive unit will still be efficient. The reason is that it has an entirely maintenance-free 16-pin BLCS electric motor. This feature offers excellent thermal stability.

For this reason, you can ensure that the 4th Gen Bosch CX will offer consistent performance after a year of use. (source)

RIDE e MTB Tip: Are you thinking about building an eBike? It isn’t very hard – Heck I’ve got step by step instructions with videos along with all the tools. Check it out 👉 How to Build a Mid-Drive Electric Bike

What Is the Most Powerful Bosch Ebike Motor?

Bosch CX 4th Gen Motor Electric Mountain Bike
Bosch CX 4th Gen Motor Electric Mountain Bike

The Performance Line CX is Bosch’s most powerful motor intended for electric bikes. Bosch updated this system in 2020 to be 48 percent smaller and 1kg lighter than its predecessor. As a result, a software update will allow the motor system to pump out 85Nm of torque, thus accelerating faster and performing better at low riding cadences.

While the unit looks impressive, users will be blown away by its robust and sporty performance. In fact, it can deliver up to 340 percent assistance while you pedal uphill.

Moreover, the Bosch Performance Line CX lets you experience well-controlled acceleration along with moderate assistance. The Active Line provides a support level of 250 percent in Turbo mode. Additionally, it offers a maximum 4oNm of torque. (source)

RIDE eMTB Tip: Be prepared (Boy Scout Motto) stuff happens out on the trail. I’ve got a guide to help – Mountain Bike Emergencies

Can I Upgrade My Bosch Ebike Motor?

According to Bosch, you can upgrade your e-bike motor’s software to the latest Performance Line CX Motor. This way, you will unlock a better riding experience and more torque.

You do not need any new or additional hardware for the update. You only need to plug your motor into a laptop to install the latest software. Even better, the new software works will all the Bosch CX 4th Gen motors.

If you own a Bosch e-bike motor, you can enjoy the new upgrade with only a few steps. (source)

Bafang Mid-Drive Electric Bike Conversion
Bafang Mid-Drive Electric Bike Conversion

Did you Know You Can Convert a Regular MTB to Electric?

Bafang a leader in DIY electric bike conversions has a mid-drive kit that will fit on most regular bikes. I’d recommend the BBSHD kit, it’s a complete setup with a huge capacity battery and a 1000 watt motor. Why this setup?

  • Heavy duty 1000 watt motor (built for cargo bikes)
  • +50 volt 17.5 Ah battery for speed and distance
  • Easy installation with provided tools.

If you’re considering a conversion, do what I’m doing get the BANFANG BBSHD 1000w eBike Conversion with Battery

How Long Will a Bosch E-Bike Battery Last?

New e-bike batteries are no longer complicated. That said, the most potent Bosch e-bike power packs are the

  • 300Wh
  • 400Wh
  • 500Wh
  • 625Wh power packs

These battery packs provide a superior range, longevity, and reliability compared to other e-bike batteries.

Moreover, some e-bikers think they need to replace their battery every two years. However, such is not valid.

According to Bosch, its batteries can last for either 500 charge cycles or two years. But that does not mean you need to replace your battery pack right after two years. The company states that you can use the batteries for around ten years or 1500 charge cycles.

Read how about what to do with a dead battery in this article – What To Do When Your Ebike Battery Dies

The battery will still work after the charge cycles. However, it will age over time, making it lose its capacity, so it can no longer power your e-bike as far.

So, if you bought a Bosch CX 4th Gen now, you will be able to use it for up to 10 years. (source)

How Many Watts Is the Bosch CX Motor?

The Bosch CX 4th Gen motor has 250Watts of power. This efficient motor makes it easy for mountain bikers to pedal uphill or on rocky and bumpy trails.

Even better, Bosch says that the battery life is expandable for up to “1125 Wh on our JARIFA² and AVENTURA² using a second, external battery.” This way, riders will achieve the range that they need.

MotorMid-drive motor, 250 Watt
Battery Capacity625Wh. The battery life can increase by 1125 Wh with an additional battery.
Charging TimeApproximately six hours
AssistanceNearly 25km/h
Assistance LevelEcoToureMTBTurbo (source)

The Takeaway on the 4th Gen Bosch CX

The 2020 Bosch Gen 4 Performance Line CX battery can last for up to 10 years. So, even after a year of using the motor, you can ease yourself knowing that it will work as efficiently as you first used it. The reason is that the motor’s battery will only degrade after ten years or 1500 complete charge cycles.

The 4th Gen Bosch CX also offers firm support. At 2.9kg and a maximum torque of 85Nm, the motor provides eMTB riders with riding enjoyment to the trails.

David Humphries Author at Ride e MTB

Hi David Humphries here the guy doing all the pedaling behind the scenes with this blog. I’ve been in the MTB world for a while and recently started getting into eMTBs. You can check out more about me HERE and on my other passion project –


  1. “Bosch E-Bikes.” A New Era For Emountain Bikers. Accessed February 2, 2021.
  2. “Bosch E-Bikes.” Performance Line CX, The Heart Of E-Bikes: Drive Units. Accessed February 2, 2021.
  3. “Bosch E-Bikes.” Software Updates Bring Even More Ebike Fun. Accessed February 2, 2021.
  4. “Bosch E-Bikes.” How Long Does A Battery Last? 11 Questions About The Ebike Battery. Accessed February 2, 2021.
  5. “Focus Bikes.” Bosch Performance Cx 2020: Powerful And Efficient For Diverse Challenges. Accessed February 2, 2021.