Review
Bosch has opinions about the limits that should be imposed on eMTBs. They believe that too much power and torque on mountain bike trails could lead to problems, in terms of public perception, regulatory controls and possibly trail restrictions. Another issue is premature drivetrain wear. The one Avinox rider at Megavolt last year broke something like three chains. Obviously, that’s anecdotal, but the bike was quite new. We took no pleasure in overtaking him on one of these occasions, immediately after he had gleefully passed us at full gas. (sorry Lorenzo!)
In 2025, Bosch advocated for an industry-wide class 1 ceiling of 100 nm and 750 W. Under pressure to compete with DJI, Specialized and other drive unit producers, Bosch has moved that needle with their recent over-the-air performance update.
Performance Update 2.0*
The broad strokes of this update are that torque goes from 100 to 120 Nm, support goes from 500% to 600% and Trickcheck, which I’ll get to below. In a month or two, there will be a drivetrain tensioning feature that keeps your chain taut when you aren’t moving, for quicker response.
The maximum support is only available below 15 kmh, and the idea is to provide this boost for situations where you need a quick jolt of power to get over something challenging. This limited-duration uptick is unlocked when the rider puts in a high effort. The idea is to give you extra power when you need it, while minimizing drivetrain wear and range impact.
*This update applies only to gen. 5 Bosch Performance CX and CX-R drive units. Bike manufacturers must agree to allow the 2.0 update on their bikes, or it will be unavailable as an over-the-air update. I have yet to hear of brands who have drawn this line but there may be some.
Very little has changed for the descent, except acceleration out of corners, and a cute little chime as your reward for allowing one or both of your wheels to leave the ground, intentionally or otherwise.
Performance 2.0 Features as described by Bosch
On very steep terrain, the Bosch Gen. 5 CX drive unit feels very close to the updated Specialized S-Works Turbo Levo I’ve been testing in terms of brute climbing force. The Levo has less Torque at 111 Nm but more Watts at 800 but support levels max out at 410%.
On The Dirt
A 20% increase in torque is no tweak, and in certain situations, it is easily felt. The drive unit handles steeper terrain more eagerly, accelerates better out of corners, and provides more push at lower cadence. All of these are welcome traits on trails, while not changing much on the road to the trails, unless you happen upon a very steep paved climb.
The regulated Class 1 speed limit of 32 kmh / 20 mph is unchanged, and above that limit, there is no motor support at all. On the road, this is a little annoying but manageable, while the European limit of 25 kmh / 16 mph seems ridiculous. The 32 kmh has little relevance on trails because you are unlikely to get anywhere near that, climbing singletrack or even fireroads unless they are almost flat or downhill.
One thing I noticed, while trying to climb very steep pitches, is that my technique had to change. Obviously, traction is a limiting factor, and I had to force myself much farther over the front of the bike than I had previously. This felt unnatural at first because I was climbing pitches that were foreign to me, which was a great sensation.
I wasn’t sure about bikes that, like Aventon’s Current and the Avinox motors, allow short times at the highest power levels. I’d like to see this on Bosch bikes, actually. Because of the way the assist levels are set up, you may not want your Turbo (highest) setting to allow access to all 120 Nm of torque, but you may want that much power occasionally for a particularly challenging climb. Having that button would give you that access without having to program it into your Turbo setting.
You could have your highest settings in Turbo mode and tune eMTB down a little on a Performance CX gen. 5 drive and spend more time in that setting, but eMTB performs differently, matching outputs to inputs more accurately, which inevitably leads to less support, which may not be ideal when you are chasing buddies on Avinox motors. I’ll play around with that some more to see if I can come up with a solution I’m happy with.
I don’t think this would have been possible for me before the update. Opening up more terrain is pretty sweet, and climbing steep trails can give you an awesome workout on an eMTB.
That Ding Means – You’ve got air!
A hilarious element included in the Performance 2.0 update is Trick Check, which records and alerts you when you do a manual, a stoppie or if you get air. The system emits a dual-tone chime anytime your wheels leave the ground, or one of them does. To my ears, it sounds like a little cheer, and it actually makes me smile regularly. That is bound to wear off, and I will probably turn it off, but that remains to be seen.
If I don’t know that my wheels are off the ground, I’m likely in serious trouble, and that little cheer isn’t going to help me. It reminds me of the feature on the Kiox display that tells me whether I am climbing or descending. How could you be a bike rider and not be able to figure that out for yourself?
I don’t recall intentionally doing a euro turn on last night’s ride, and certainly not an endo/stoppie, but the app says I did 4, including one that lasted 2.2 metres. Maybe on a rockface with my rear wheel mostly unweighted? The air stats are kind of fun as well, and apparently, I dropped 2.3 metres and gapped 3.3 metres. Nothing to write home about, that’s for certain. On another ride, it suggested my max jump height was 26.6 m or 87′, which strikes me as unlikely.
Maybe there will be some discrepancies in these stats while they work out the kinks? Apparently I performed 4 stoppies, including one of 2.2 metres that I never noticed. The jump stats from the same evening sound more accurate, in the middle shot. The icing on the cake is the left screen cap, which describes an air that was 8.9 metres or 29′ long, and 26.6 m or 87 feet high (assuming it was the same one). Max air duration was 6.7 seconds, which would be a fairly long time in the air for me. Particularly considering I don’t recall this happening at all.
The Install
There was quite a lot of rumbling suggesting it might be necessary to take your bike to a shop that has Bosch diagnostic tools to do this upgrade. That should not be the case. The process is straightforward but not timely. You’ll need either the 5th gen. Performance CX or CX-R drive unit (or the 5th Gen. Cargo motor) to get 120 Nm of torque, and the other upgrades but Gen. 4 motors get some software refinements and 600% maximum support.
Step 1. Open the Bosch Flow App and connect to your bike.
Step 2. Ensure your App is updated to ver. 1.35 or higher
Step 3. Check to see if the firmware of your drive unit needs to be updated. If it does, perform that update before the Performance 2.0 update.
Step 4. Install Performance Update 2.0 note – you’ll need to stay with your bike and connected to the network while this transfers from your phone, and it can take up to 20 minutes.
Step 5. To begin with you’ll see a blue banner on your app with a link to a page explaining the compatibility required to perform the update to 120 Nm etc. At this point, it could take up to 24 hrs until the blue banner changes to say “Adjust performance value of your drive unit” or “Performance Upgrade 2.0”. Mine hadn’t shown up after 24 hrs so I deleted and reinstalled the app, and then it was there.
Step 6. Go to
- eBike home screen
- Settings
- Components
- Drive Unit
Step 7. Once in the drive unit settings and you can see one of the blue banners mentioned above, click it and follow the installation procedure. Once that has been done, you shold be able to adjust the torque value higher in the mode adjustment from your bike’s home screen. The 600% assist doesn’t show up as a percentage for me – simply 1-5 which I think means 5 now offers the 600%. (but this one goes to 11)
If after 24 hrs you aren’t able to see the banner, you can try logging out of the app, reinstalling the app, disconnecting and reconnecting your bike, or just going to have a beer and text your friends about how frustrated you are. That should do the trick.
Why is this Happening Now?
It’s easy to see this as a response to DJI breaking the eMTB arms race wide open. First, they smashed through the ceiling with their original motor, the Avinox M1, with 120 Nm of torque available in short bursts of 30 seconds and up to 1000 W of power, and now they have up to 150 Nm and 1500 W, or twice as many as Bosch.* Obviously, there is more to a motor than raw numbers, and Bosch is well known for refinement and controlled power delivery, not to mention what may be best in class reliability. DJI is too new and hasn’t yet been in the wild in numbers that can be used to determine the failure rate. There hasn’t been an outcry from owners, however, so Avinox motors may well turn out to be reliable. Time will tell.
*It seems the latest DJI update will be forever known as the Avinox Apocalypse
The DJI motor scored points for other features as well, like the sensor ring, which detects wheel speed 42 times per wheel revolution, rather than a single time for the Bosch magnet, and for ample adjustability within the system. It is sensitive enough to determine what cog you are in, apparently, even with a conventional drivetrain and helps control traction. DJI already allows you to adjust boost overrun, which is a feature of both units (and others) that keeps the drive going for up to 2 metres after you stop pedalling. This feature can be very useful, but it’s also challenging before you are used to it, and for novice riders. Making this adjustable only makes sense for safety.
A nice thing about virtually all of the adjustments on the Avinox motor is that they can be tweaked from the touchscreen. In fact, once you have registered your bike (DJI makes this mandatory after 100 km travelled)., you don’t need the app at all, apparently.
None of us had torque envy when two riders showed up on this bike for our weekly night ride. Really. Or power envy. The Forbidden Dreadnought E is even nicer looking in person.
Two Dark Horsemen
On my weekly night ride, there were two riders on new bikes, and both were on the DJI Avinox M2S-equipped Forbidden Dreadnought E. The version they were riding didn’t have the battery to get them full power, the poor dears, so they were limited to 150 Nm of torque (in 30-second bursts) and a mere 1300 W of power. One of them had been struggling to keep up for months because he was on an older Shimano drive with a smaller battery, and he couldn’t wipe the smile off his face on his new rig. They showed off their power a few times (one of them in particular) and lorded it over us appropriately, but we could still ride together, assuming they didn’t light the afterburners on the way up the fireroad. The bikes were beautiful, and they couldn’t stop grinning, but of course, there are questions: about battery life, drivetrain wear, and getting along with other riders.
What Will the Future Hold?
With 11-year-olds wheeling down main streets on Surrons and other e-motos, there are a lot of people unhappy with the electric mobility segment, and ample vitriol and angry discussion about the need for increased regulation. This could easily spill over to the eMTB Class 1 segment, whether justified or not.
Obviously, there should be some sensible limits put on eMTBs that will be expected to play nicely with pedal-powered mountain bikes. If this does come to pass, and bikes are regulated by their manufacturers, it seems likely the limits will land below DJI’s M2S drive unit’s current output. Will this mean over-the-air downgrades forced upon riders, meaning they will end up with less than they paid for after having their bikes downgraded without their consent? I’ve seen eMTB riders online discussing getting their Avinox bikes soon before places like California put aggressive limits on output. At this point, this is all theoretical, but it certainly could happen.
I would be just fine if the limits ended up where Bosch has drawn the line (assuming all my buddies don’t get more powerful motors). At the risk of agreeing with Hans Rey, this seems like a sensible level for cohabitation with pedal bikes while still providing performance that is a clear alternative to muscle power only. And I swear this isn’t just sour grapes because I don’t currently have a bike with an Avinox M2S drive unit. Honest.