Bosch SX: Is this the new natural?
Words Nathan Petrie
Images Cameron Mackenzie
Looks can be deceiving. Something may appear small or neat, but take a peak under the hood
and you’ll find something much greater
In the bike world, we lust after the lightest (and latest) technology but, at the same time, we never want to give up that purity of the ‘natural’ ride feel. At the forefront of our communal infatuation with ‘bike porn’ is the eBike. Is it possible to embrace the technology without giving up on the simple joy we get from pedalling a bike?
Since Covid, eBikes have become commonplace on our trails and the daily ride for many of us. The maturing market now provides a wide range of eBike products for every style of rider. From full-power to lightweight motor options, a variety of battery sizes, and matched with different bike brand geometry. Bosch has led this charge and the arrival of their Performance Line SX system in New Zealand is the next phase of this evolution.
When the opportunity came through to test ride the new Mondraker Dune R, equipped with Bosch’s Performance Line SX, my interest was well and truly piqued. My current bike is fitted with the Performance Line CX, and I knew the SX was a light-weight system, so was keen to see how it would compare. We headed for the rugged terrain of Matangi Station in Alexandra, to put it through its paces; the perfect proving ground for both the system and bike with steep climbs, tight pinches and rocky single track.
My most obvious question was how the SX motor would feel in terms of assistance compared to my experience on the Performance Line CX. Would it feel underpowered or too much of a jump down? How natural would it feel to ride? I was also interested to see how you use the modes. For the type of riding I do, I usually ride my CX bike in the two lowest modes, Eco and Tour, but I wondered if I’d need to use eMTB or Turbo? Or, if I stuck to my usual modes, how fast would I be able to climb up stuff? Would I feel like I was going a whole lot slower? Would the SX system experience be up to Bosch’s usual high standards?
I put the motor to the test straight out of the car park, climbing up a steep four-wheel drive track to access the trails. I didn’t expect the SX to be as strong as a full-power motor like the CX but it was easily powerful enough going up. I didn’t need to switch to eMTB or Turbo mode. Even on the loose gravel surface, where you can easily lose traction on the steep sections, the bike performed well and I could push through without having to get out of the saddle.
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I think a lot of experienced riders still yearn for that analogue bike feel and the lower-powered modes deliver that nice balance of assistance.
On an eBike, you can sometimes feel like the front wheel is going to lift off on steep sections, especially in high power modes, but I didn’t experience any of that pull-up at the front. I felt like you could manage the torque and it was well delivered. It was smooth and consistent and didn’t come on in a big burst.
I had heard that the SX is more cadence- sensitive but even so I didn’t have to spin it up as quickly as I thought I might have to and was getting good assistance low down. It wasn’t hard to get used to it either. I just had to drop down one gear and I was set. I was still covering the ground fast and it felt really natural.
My personal preference when it comes to modes on my CX powered bike is to be in Tour mode 80% of the time, maybe eMTB mode if I’m going up a more sustained technical climb. I never really feel like I need Turbo and I hardly ever use it. I love to pedal but still want that assistance when I need it. I think a lot of experienced riders still yearn for that analogue bike feel and the lower-powered modes deliver that nice balance of assistance. Eco and Tour don’t feel super strong on a heavier bike so I thought I’d see how they felt on the SX. I switched to Tour on the steep sections and it was ideal, giving me the assistance I needed.
I had a try with eMTB and Turbo and found they were good for starting on a steep technical climb, getting you into it without feeling too strong. This is where these modes come into their own. In the spots where you’re at a low cadence and can run out of traction pretty easily, those high- power modes can help you get moving without having to worry about spinning the wheel and losing grip straight away. You get the torque that you need, where you need it. With eMTB mode you can get up and over most things and it’s the most intuitive mode for most types of riding.
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The PowerMore 250 range extender is a good size, weighing in at just 1.5kg and sits on the bottle cage mount. Even though you’re carrying the minimal extra weight, you’re not going to be suffering anymore because you’ve still got the assistance from the motor and the bike is already lighter.
In the morning, we used about 40% of the battery, then rode three hours in the afternoon on some pretty steep, techy terrain, all on one battery charge and I never felt any range anxiety. We didn’t have the Bosch PowerMore range extender with us, but it would be ideal on big days like this. Having the option of an extra 250Wh on top of the 400Wh from the Bosch CompactTube 400 that comes on the Mondraker Dune R is a huge bonus.
The PowerMore 250 range extender is a good size, weighing in at just 1.5kg and sits on the bottle cage mount. Even though you’re carrying the minimal extra weight, you’re not going to be suffering anymore because you’ve still got the assistance from the motor and the bike is already lighter. It’s much easier to add 1.5kg to your backpack than a full-size second battery and it widens the scope for more ambitious backcountry missions.
The Mondraker Dune R has a system controller installed in the top tube, so you can do a quick glance down to check how much battery you’ve got left and what mode you’re in. I liked not having a display unit to clutter the cockpit. But if you prefer having a display unit you can have this added on. Having a minimalist eBike setup with only the system controller and mini remote, but the Flow App in your pocket, means you’re getting the best of both worlds: a pure riding experience with the reassurance of powerful data in your pocket so you can quickly crunch big numbers if you need to. The Mini Remote next to the grip is great. If you’re in a tough spot where you need to change the mode easily and quickly, it behaves responsively.
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Going on a deep dive on the bike itself, The Dune R is a solid package. Mondraker has three tiers of the Dune R and this is the most affordable. Build-wise, this is in line with what you would expect at this price point. The headset was super clean with the internal cable routing; that was a nice touch and didn’t impact the steering range. Having the 180mm fork on the front means it’s quite a burly bike. I had thought it would be a bit of a handful but was pleasantly surprised on some of the tighter spots we rode; it still felt light and manoeuvrable and handling was really good. Mondraker uses their own patented dual link suspension design where the shock is compressed at both ends. This gives the bike amazing pedalling efficiency, a very progressive nature. It felt lively and responsive, firm but still plush. It was also very quiet and the build quality was immaculate. The geometry was that classic Mondraker style from their race pedigree – an aggressive approach for descents where you’re tucked in but, if you’re sitting down climbing, it puts you in a good spot. Mondraker also has a unique approach to its high-end carbon bikes. They use pure Toray Carbon with a unique layup to achieve low weight, high strength and stiffness. Most carbon frames are composites where carbon is mixed with fibreglass, so this is very solid. The bike itself really is an amazing first pairing with the Bosch SX system. I think the overall aggressive approach of the Dune makes this a compelling option.
After riding this bike, I asked myself who the bike and – specifically – the Bosch SX system could be suited to?
For advanced riders, the eBike choices are really interesting now, especially if you’re someone who’s come from an acoustic bike. This bike and system is not such a drastic jump as it would be to a full-powered eBike. It has a super-natural feel; you’re taking an analogue experience and you’re just giving it enough assistance but not in a heavy- handed way. Likewise for existing eBike riders, this presents a really different ride experience.
This system will suit someone who loves technical climbing and still wants the capability to manoeuvre, but understands that it is going to ride like a trail bike on the descents as well. It has got the right amount of torque, you can spend most of your time using the low assist modes but with the reassurance that you can bump up to eMTB when you need it and dial it back down when you don’t. Even if you’re riding with people on non-eBikes you can still chuck it in the lowest mode and ride quite naturally in a mixed group, which is sometimes difficult to do with a full-powered eBike.
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This system will suit someone who loves technical climbing and still wants the capability to manoeuvre, but understands that it is going to ride like a trail bike on the descents as well.
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I think this could be the ultimate system for backcountry and hike-a-bike missions. The SX has plenty of torque and power, so you can climb the more unusual trails you come across on backcountry outings – and having the option of the range extender gives you that certainty of range. An eBike assists you in exploring places you otherwise wouldn’t reach, but there are always sections where you’re going to have to carry your bike over deep river crossings, where trees are down or you’re navigating a washout. Hauling a bike over that unexpected stuff can be taxing and this is where the weight is really important. Walk mode with the lighter weight system is also a breeze.
To sum up, it was an amazingly fun experience to ride this eBike and I was well and truly surprised at its capability. I was already familiar with the Bosch system so the SX felt comfortable while also bringing in some new experiences. Everything was developed to the expected high standard, from the overall system to the Flow App. I think the SX system fills a really broad part of the market and it actually strengthens where its full-powered CX offering fits. Once people ride it, it will change a lot of mindsets. The system that bridges both the eBike and the analogue worlds – you can have your cake and eat it too. This is the new natural.
Special thanks to Outside Sports, Matangi Station and Mondraker NZ (Allsports Distribution).
The Mondraker Dune R is available for purchase at outsidesports.co.nz and nationwide. For a full list of Mondraker NZ retailers visit mondraker.co.nz
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