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Electric Mountain Bike Motors Explained

Views: 142     Author: Site Editor     Publish Time: 2023-11-30      Origin: Site


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There are so many types of E Bike motors to choose from. But it's crucial you get it right because it's going to be on the right dynamic, and the performance on the trail. So today we're going to talk about the different types of motor and which one you might want to choose.

So what motor do you choose, Bosch, Shimano, Brose, Rocky Mountain, Panasonic, Yamaha all have their individual motors and they all have their certain characters. It'smore than just power here that we're going to be talking about. What I also want to make clear from the start is we're talking pedal assist, not throttle assist. Talking mountain bike, not motor bike. 

Different types of motors

There are three main types of E bike motor. The first one is hub mounted, so that can be mounted in the front hub or the rear hub and that's where the drive comes from. The disadvantage of them is that they affect the suspension quite considerably and they're found mostly on hard tails or shopping bikes. The second type of unit is a bolt on system. These are custom fit to a standard mountain bike. They tend to be a little bit heavier than a hub or a mid drive unit, and also you need to carry the battery in a backpack. It's the kinda system that Martyn Ashton used when he did he trip to Whistler last year. The third type of motor is a central, or mid drive unit. The benefit of these motors is they're smaller and more compact which allows the frame designers to make the geometry closer to a normal mountain bike. Today, we're going to be focusing our attention on these mid drive units. It's also worth noting that they're restricted to 25 kilometers an hour depending on the country.

So before we get into the nitty gritty of E bike motors, I want to point out that you shouldn't choose your E bike based on the motor and the same way as you wouldn't choose a normal bike based on the crank. We have to bare in mind the geometry and sizing all do matter, it's going to have an effect on the agility and the stability of the bike. And we're going to cover that on a later date. Today, we're just focusing on the motors.

Motor weight

Let's talk about weight of E bike motors, in general they're about three and a half kilos. This Bosch unit's four, where a Shimano is 2.8 kilos. Does weight matter? Well, not as much as such things as size or its location in the frame. When we're talking size, a smaller motor allows more freedom for frame manufactures to make bikes with good geometry. At the same time, it's pointless having a light-weight motor in the wrong part of the frame. So, weight does matter but I wouldn't get hung up on it too much and it's more than likely that the weight of bike motors come down significantly the next few years.

Motor power

About torque levels, we're not going to go into physics at this point. In general, they range from about 70 newton meters on a Shimano drive, to about 90 newton meters on a Brose unit. Does torque matter? Yes, it does it has an effect on how the power's delivered to the back wheel. A lot of people talk about level of support, it's a very simple subject. It comes down to how easy or how hard it is to pedal your E bike.

It comes down to the level of assistance that that motor is giving you. Eco mode is going to give you about 50% assist, where as turbo is going to give you about 300% assist. It varies between brand to brand, but the principle is roughly the same. The bottom line is it's up to you to decide how you use that power.

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E-bike software

Let's talk about software and software updates for your E bike. My heart usually sinks when I see this on my phone and that's all it is, it's the same as updates on your phone. But on an E bike, it's there to get the best performance out of your motor and you know what, it's as simple as downloading the app, connecting to your bike, and you can get all kinds of information. On some brands, it tells you when the motor needs servicing but in general, it tells you everything about the general health of your motor, a key part to E bike maintenance. 

Motor resistance

One really important subject that needs covering is resistance. What exactly happens when the motor stops assisting you pedalling and after which point you're doing everything under your own steam. This changes from motor to motor, but essentially on some systems, the drive decouples meaning it's a resistance free ride. You can pedal like a normal mountain bike really. And then another is there's an element of drag in the system so it's a little bit harder to pedal. Okay, so what you're going to be asking me are what are the ones that are resistance free?

Motor care and maintenance

Right, let's talk about E bike motor care and maintenance. These motors on the whole are pretty bullet proof, in fact some are hermetically sealed which means that no grime or dirt can get into the system. However, just like other things such as cars, motorcycles, hairdryers, and drills, the same rules apply, they're not big mates with water. So I think when it comes to maintaining an E bike motor, pressure washers are wrong, it's more like a bucket and sponge approach. One tip you might want to use is get a track pump to evoke any moisture out of the system. If not that maybe a hair dryer or a DA compressor. It's only at those points that you really should be looking to taking the bike to a dealer to get it sorted out. Most problems are easy to resolve. On the whole, E bike motors are pretty more approved for units. But yeah, don't go wading through a river with the motor totally submerged, if you don't do that, you'll be all good.

Okay, that's an overview then of the kind of general topics surrounding E bike motors. It's probably time now to get into the real nitty gritty, the specifics of each E bike motor. 

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Shimano steps system

We're going to start off with the Shimano steps E8000 system. First up, the modes that are available. There's three modes on the Shimano Steps. You have eco, trail, and boost. And the boost will give you 300% level of assist. Not only that, you can actually customize each of those settings to suit your particular type of riding.

Let's talk about the switches and displays on the Shimano system. It's very simple, there's two types, one is like a traditional mountain bike shifter, whereas the other one is really more compact in it's case of plus or minus. The display on the Shimano unit is really neat, it's well protected behind the handlebar and it shows the gearing, the power assist level, and also the battery range.

The really cool thing about the step systems, you can customise each of the modes to suit your style of riding, it's a really nice feature. You do that by way of an app called E-Tube, which you can download onto your phone and in that way you can customize all the mode settings, you can check for firmware updates, you can pretty much go into whatever level of detail you want to, so yeah, E-Tube app is what you need to tune into.

What are the characteristics then of the Shimano step system? Well, overall it's really natural to use this one. When you're pedaling the bike, irrespective of how much cadence, how much you're spinning the pedals, this motor will still support you. And also a really cool feature actually is that if you pedal in trail mode, it actually manages your output, so it's a little bit like driving an automatic car in those respects. What I will say is there's a big jump between trail and boost mode, you use trail for flat ground and transfers, but only the boost for super steep technical climbs to winch your way out.

Overall, the motor's pretty small and compact in 2.8 kilos so it means that a lot of the bikes with a Shimano motor have got a really good geometry to them. 

Specialized system

Let's move on to Specialized. In terms of the modes and support levels, there are three, eco, trail, and turbo. What's cool about this system is that through the mission control app, which you can download, you can adjust the motor currents in each of those modes, so the range is actually infinite on this system. All you've really got is a small button on the handlebar which is plus or minus per assist. The Specialized philosophy is you focus more on the trail than on a display.

Having said that, if you need to there is an integrate display on the down tube which shows how much battery is left and what power assist you're in. There is actually an after market garment unit available if you need to bolt something on. But like I mentioned earlier, there is mission control which gives you every single level of detail you could ever want.

Okay, what are the characteristics of this Specialized unit? It's protected, it's simple, it's natural, it's integrated, and it is super silent. So when it comes to riding it, it's got really variable power in one mode, and you tend to use trail quite a lot of the time cause it'll give you a constant output. There's definitely a sweet spot in the cadence, the amount you can spin the pedals at around 70 to 90 RPM. And also, when you go from trail to turbo, there's quite a big step so again, like Shimano, you're only going to be using that for the super technical, super steep climbs. What's it like when you get past the speed limiter? Pretty good, it decouples really well so when you reach that peak, that part where you have to pedal under your own steam, it's actually quite easy to do this on a Specialized system. Who uses the system? Just Specialized.

Bosch system

Okay let's go straight in with the Bosch system. Bosch have five motors but this is going to be the performance cx that we're going to be talking about. In terms of mode and support levels, it has four. It has eco, tour, EMTB, and turbo. And the cool this about Bosch is that that EMTB mode manages the outputs for you, so it's pretty much like I mentioned earlier, it's like driving an automatic car, it's really cool.

Bosch have three different levels of switches and displays, they have purion, intuvia, and neon. It's the purion which you see most on E mountain bikes, and it covers everything such as, charge, speed, mode, range, trip, and total distance. If you go to the kind of flagship, the neon, it's insane, it's almost like a personal trainer, it's got everything in there.

So what's it like riding the Bosch system? Well pretty simple, it dishes out the power really progressively, and like I mentioned earlier, that EMTB mode which is like riding an automatic or driving an automatic car. I think the key thing is that philosophy, it's the focus on the trail rather than fiddling around with the buttons all the time. So overall it's a really good system. If you do use it in turbo, you need to be really careful on hill climbs because there's a little bit of override which can push you out the edge of the corner. Also, maybe when you're going past that level of assist where everything comes under you're own steam, there's a little bit of drag in the system. And also it's a little bit noisy, but overall it's a pretty solid package, the Bosch system. Who uses it? like High Bike, Cube, Scott, Burgamot, La Pierre, KTM, it's a really popular system. 

Rocky mountain system

Rocky Mountain's a really straight forward one. When it comes to the level of support and the modes, there's three, I don't think they do have a name, there's kind of easy, medium, or hard.

In terms of display, there's no display, there's just the switch similar to the Specialized system. Although it does have a indicator of how much battery you've used. When it comes to apps for the Rocky Mountain, there is one you can download on your smartphone and that can manage everything from the levels of support, and each of the modes to maintaining your motor, and it's something a dealer can use to diagnose any faults with the bike.

So what are the characteristics of riding the Rocky Mountain properly? Well, you'll definitely find you'll spend most of your time riding in the middle trail mode on this bike because the top power mode is simply ludacris. However, you don't need to worry too much about how much you're spinning the pedals, what cadence you're in, because it'll support you no matter what. In fact, the power delivery is really really smooth in whatever mode you ride on this bike.

A key part is the pickups, so because the engagement is so immediate, no matter how steep the terrain, if you stop and start, you can keep going really really easily on this system. So there's no drag, there's no lag, and if you maintain it and lube it really well, it's super quiet too. And what brands use this system? Just Rocky Mountain. 

Yamaha system

Okay let's talk Yamaha, let's talk modes and support levels. The Yamaha has five support levels on this bike. It has eco plus, eco, standard, high, and extra power. It's worth mentioning on giant bikes, the system is called sync drive pro and it has 360% of support.

When it comes to switches and displays for the Yamaha system, this varies from brand to brand. For example, what they use on the giant systems is quite different from what they use on the high bike system. However what it does give you is a whole range of information which is really quite engaging to use while on the trail. There's an instant engagement with the Yamaha PWX, which means that on super tight climbs, no matter if you drop down to low speeds, you can pick up again really quickly. So in that respect, it's a different kinda strength of the system. It works better on lower cadences, that means you're going to be spinning the pedals at a lower speed, it kind of works really well, whereas if you're spinning the pedals on higher speed, it tapers off a little bit.

Overall, I think the philosophy with the PWX system is that you tend to use the mode switch quite a lot in comparison to the Bosch EMTB mode, which is like you're riding autopilot pretty much. So, that's quite a big difference, it decouples reasonably well, so it's pretty easy to spin those cranks. In terms of noise, it's probably on the moderate scale. Overall you could argue it's a less common system than some of the others but it's never less used by giant and high bike.

Thanks for reading this article on E bike motors. Also, we have other article about batteries of E bike system. Any question please let us know in the below, thank you. 

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