Comparing Bosch mid-drive units and understanding the pros and cons of each
The world of eBikes is full of competing designs, philosophies, and technologies. What I’d like to do with you right now is talk about one company in particular – Bosch – and compare some of their mid-drive eBike motors in order to demystify some of the technicalities and specifics of each. More exactly, I would like to answer a question that I hear a lot when in bike shops: what is best Bosch motor for my needs?
To answer that question, we must first take a look at the full lineup of Bosch pedal assist motors that are available to us in Canada (The US has one model, the Performance Line Speed, that isn’t available to us as it exceeds the 32km/h maximum speed law that governs ours eBikes). There are 4 models available, starting with the Active Line, then the Active Line Plus, the Performance Line Cruise and finally the Performance Line CX. As I mentioned earlier, each one of these motors has a specific use case and particular characteristics that might make it the ideal (or not) motor for your style of riding.
The first technical aspect we should cover is the raw torque that each unit is able to output. The Active Line has a max output of 40 Newton Meters (Nm), the Active Plus gives you a bit more torque, at 50Nm, the Performance Line Cruise clocks in at 65Nm and the Performance Line CX comes in at a whopping 75Nm (!). What does this mean? Torque is the measure of how quickly and easily you will accelerate, especially at a low cadence. This is incredibly useful for mountain bike riders who often need that extra help making it through treacherous trails. This extra “oomph” comes at a price though, the Performance Line Cruise and Performance Line CX models come in at almost 2 pounds heavier than their Active Line counterparts. On top of this, the more powerful motors will require more energy, thus draining your battery faster. For most urban and casual riders, the Active Line and Active Line Plus are the perfect mixes between power, weight, and performance. Let’s get into that a little more.
The Active Line and Active Line Plus motors weigh in at 2.9kg and 3.2kg respectively. Lighter than their Performance Line brothers, these units offer a very nimble and sporty drive. This being said, in my opinion, the slightly heavier Active
Line Plus motor really nails it when it comes to balancing all the important factors that riders are looking for in a mid-drive eBike unit. It offers 10Nm more torque than the entry-level Active Line motor, making it more versatile if you live in a hilly area or if you simply prefer a peppier motor.
The Active Line Plus motor offers some great features that are often overlooked but, in my mind, are big bonuses when comparing the Bosch motors, and more specifically the Bosch Active Line Plus motor, to other brands currently making eBike drivetrains. One of these features is the cadence support, which in the Active Plus Line has a top line of 105RPM, meaning that most riders won’t ever be pedaling quick enough to not get amazing detection from the sensors on this motor. Another very important feature is the use of Bosch ISIS splined crank interfaces, which is essentially the industry standard on quality bikes, versus the square-tapered cranks which won’t provide the same level of reliability in the crank connection point.
Another point that is often overlooked but once pointed out, is much appreciated, is the lack of noise coming from the drive. The Active Line Plus is noticeably quieter than the Performance Line motors, perhaps due to the fact that the Active Line Plus has no reduction gearing system, meaning that it maintains a 1 to 1 ratio with the pedal crank which also facilitates swapping out your chainring when it becomes worn out.
Finally, the last feature I would like to discuss is the fact that you can actually pedal backward on the Bosch Active Plus motors and the chain cycles backward with you! This is a big plus not only for riding – many motors have a frictionless freewheeling backpedal action that can sometimes be hard to control. The benefit of this is that the pedals always stay where they’re supposed to and, shout out to the cyclists who religiously maintain their bikes, they can lube the drivetrain up without ever having to put the bike in a stand (or getting your buddy to hold the rear wheel up for you)!
To conclude, I believe that for most urban and traditional cycling use cases, the Bosch Active Line Plus motors offer the best all-around performance, in a lighter, cheaper (often 500$ less than the Performance Line motors) and quieter format. If you have questions about the Active Line motors or any other Bosch products, feel free to swing by the shop. Our Bosch-certified technicians will take as much time as necessary to explain the intricacies of each motor and make sure you are comfortable and confident when you decide to get your very own Bosch-equipped eBike. Until then, happy riding!