Join over 6500 MTB fans on Facebook.
2020 bosch cx review
The ultimate e-MTB motor?

Review: 2020 Bosch CX 4th Gen first ride review

Smaller, lighter and better. We ride the 2020 Bosch CX

Reader Rating36 Votes
2020 Bosch CX motor review

Bosch has stepped up to the plate an hit a home run with the newest generation Bosch CX 4th Gen motor drive system. Keep reading for our first ride impressions and review.

Think of a Bosch mid-motor system fitted to a mountain bike or city bike and you will remember those large drive systems that were so big that designers were forced to compromise chainstay length and suspension systems just to fit it in.

The previous generation Bosch CX was a large motor, featuring a tiny chainring. It was heavy, bulky and not the best to look at but it wasn’t all bad.

Bosch’s internal Power Tube battery system is one of the more aesthetically pleasing on the market and ensures that frames can hide large 600Wh cell’s in the downtube.

The Bosch software was also unrivaled too featuring 4 x modes including the rather brilliant e-MTB mode, a mode that I rarely move away from when on my Bosch powered e-MTB rides.

So with a good battery system and quality software, all that was really needed was a significant update to the motor and that’s what Bosch has managed to pull out of the bag for 2020 with the 4th Generation Bosch CX motor system.

Review: Bosch CX 4th Generation

2020 bosch cx review
Smaller and lighter than before.

Right out of the gate the new Bosch CX 4th generation motor looks the part. It’s a physically pleasing design that is now almost half the size of the original motor, and weighs must 2.79kg vs 4.09kg of the original for a weight saving of 1.3kg.

Both the original Bosch CX and new 4th Generation motor offer the same 75Nm of torque but the new motor’s turbo mode now offers 340% assist vs 300% of the original. The highly adaptable e-MTB mode also receives a significant boost in assist making it one of the most flexible systems on the market today.

Review: Bosch CX 4th Generation first ride impressions

2020 bosch cx review
The ultimate e-MTB motor?

As soon as you begin to pedal you will feel that added level of assist and for riders who want to really get as much ride time from the Bosch system they have both the Eco and Touring modes to play around with.

For our ride, which was made up of undulating off-road trails with a few road climbs, most riders opted for e-MTB mode for the off-road sections and Turbo for a fast climb back to the top.

Those road climbs are quite an eye-opener and you’ll quickly realize that Bosch’s new system cuts out at a slightly faster speed than the official 25k/Mh. Apparently, EU rules allow for 5% of wiggle room in the top speed of a pedelec so Bosch has tuned the 4th gen CX to push the rider right up to those legal limits. This will be a welcome surprise to everyone but your fellow e-MTB riders for if they’re on a rival system you will leave them for dust.

Power flow and torque is smooth yet powerful. The CX has 5Nm more torque than a Shimano STEPS system, but that power is put to the ground in a more controlled and refined way for better grip and more precise control.

When freewheeling or after hitting the speed limiter, the motor switches off gradually with no sudden power off and there is very little notable drag from the system.

Review: Bosch CX 4th Generation what’s great

The size, power and assist of the Gen 4 CX are all very impressive, and I’m quickly becoming a Bosch convert. E-MTB mode is the most versatile mode of any e-MTB system that we have tested to date, just remember to be smooth with your pedal strokes and not to mash away to keep your rubber gripping rather than slipping.

Review: Bosch CX 4th Generation what’s not so good

It’s quite noisy, much nosier than you might expect and this is either going to bother you or not. As a rider who doesn’t actually mind the robotic sound of an e-MTB motor, especially one so capable, the sound doesn’t upset me. What we did find though are that the motors we tested varied in the amount of noisy the produced with some being quieter than others.

2020 Bosch CX is a Huge Improvement!
The new Bosch CX 2020 system is better than the original Bosch motor in every single way, but it is a little on the noisy sound. The size and weight savings it offers will mean that new Bosch powered bikes will be more attractive and more refined, while the powerful motor and added assist are sure to propel those bikes to the top of many e-MTB riders wish lists.
Reader Rating36 Votes
Lighter weight
2020 Bosch CX motor review