Storck eGrix vs. Grix.2: How much influence a motor has on a gravel bike
Timo Dillenberger
· 23.06.2024
It feels like a conventional bike! If this statement, often used by marketing experts, applies to any type of pedelec, then it is most likely to be true of racing and gravel bikes with electric assistance. This may sound paradoxical, as they are the lightest models in the world of e-bikes. You might think that charging the motor and battery would compromise handling, manoeuvrability and even looks. But the manufacturers have also realised that they don't have to put everything technically possible into such a bike. Instead, they are focussing on the virtue of modesty.
Due to the sensitive riding physics of an e-gravel bike compared to heavier downhill bikes or SUVs and the agile handling of a lightweight road bike, e-gravel bikes tend to forgo maximum power, control bells and whistles and battery capacity. Among our carefully selected E-gravel bikes from another test, we found relatively light pedelecs that are barely heavier than a mid-range biobike. This is exactly where we come in. We wanted to find out how big or small the difference between gravel and e-gravel really is.
That's how similar the Storck eGrix and the Storck Grix.2
In order to make a fair comparison, we looked for a pair that was as similar as possible except for the drivetrain. Our search led us to the carbon forge Storck, where we discovered the Storck Grix.2 and e:Grix. Although they are not exactly the same, their frame geometries have identical millimetre precision. The Q-factor, i.e. the horizontal distance between the feet when pedalling, is also identical on both models.
The e:Grix is equipped with the X20 rear motor from Mahle, which offers a torque of 55 Nm. This means that no modifications to the bottom bracket are necessary. The biggest difference is the additional weight of one and a half kilograms, which is mainly located in the rear wheel hub. Another pound or so is added in the down tube of the frame. The effects on aerodynamics due to slightly thicker tubes on the pedelec are negligible. To summarise, the question arises: How does the additional weight and the weight distribution negatively affect the riding characteristics and how does this relate to the dynamic advantage of the motor? And what impact does this have on riding enjoyment?
Tester and test track
The human factor in the test was me. My personal data such as "frame height", weight, continuous performance, maximum power and heart rates for long distances and intensive efforts are known. As a passionate cyclist, I am familiar with my values. However, in such test stories, I always try to simulate other types of riders - in other words, to ride like readers with more power and riding skills or even like absolute beginners.
The test lap on which the duel was to take place was deliberately designed to be short and varied. It led through the picturesque Bergisches Land region and included a high proportion of gravel paths and few roads. With some challenging climbs and technical sections, it was typical of a Sunday morning ride. The range in the diagram below is not a measured value, but a realistic estimate. The exact value can depend heavily on external factors.
Storck eGrix vs. Grix.2: Minimal differences
The duel lap was my first ride on the e:Grix gravel bike. I had previously tried other gravel bikes with a motor, but the rear motor of the e:Grix surprised me in a positive way and gave me a very natural riding experience. The route to the Bergisches Land was mostly flat and apart from traffic lights and junctions, I hardly ever rode in pedelec mode. Both the e:Grix and the non-motorised bike are real athletes, with a crisp riding position and good pressure on the pedals in every grip position. Together with a little tailwind and the smart tyres, I was able to exceed the speed limit at which the drive deactivates every time.
I didn't miss the quick start at traffic lights of city pedelecs. The e:Grix makes good progress even at the lowest setting. With the Storck Grix.2, only the first few pedals are different. As it is even lighter, the acceleration is similarly impressive. You lose two seconds per traffic light compared to the e-bike - and maybe one more at the next stop. Maybe I'm imagining it, but you can feel the extra weight at the rear. However, this is less of an issue when cornering. Here, the e:Grix benefits from its rear motor, while the front section steers just as quickly into corners without any additional weight. If at all, you notice the difference when changing direction very quickly.
The motor has the advantage here
The Mahle motor makes a big difference, especially on inclines and in deep sand. Here the effort is considerably reduced, which is of course logical. However, you don't ride significantly faster. Personally, I intuitively concentrate more on keeping a clean riding line and not pedalling as hard as possible. With the Storck Grix.2, it's fun to push yourself to the limit, but with the motor and maximum pedalling power, the speed would almost be a bit too high.
Although I found myself in a kind of "racing situation" without really thinking about it, I used the drive more to relieve the strain than to gain time. And not to forget: also for more comfort! By pedalling in a heavier gear, you generally sit more comfortably over hill and dale, which meant that the large sprockets of the e-bike remained almost unused. This was an absolute bonus when riding over the roots in the Bergisch Forest. On the Grix.2, on the other hand, I had to get out of the saddle more often.
Draw in comparison?
The data collected from the lap makes a conclusion superfluous, so to speak. It is noticeable that I was hardly any faster despite a significantly higher power output and additional energy from the battery. And that wasn't because you lose time on bends or descents with the e:Grix. The drive would only bring a real time gain if you force yourself to use it as often as possible. But riding like this feels very cramped! If you use the motor intuitively, the effort simply goes down a notch. My significantly lower heart rate speaks for itself. And that wasn't because I was taking it easy with the e:Grix - the maximum heart rate is similar.
The riding performance with and without the motor is similar to the technical data. The pedelec only provides support in the strenuous moments and ensures a somewhat flatter pulse line. If there were long hills in the Bergisch region, the pedelec would probably have had more advantages. What about the fun factor? Which bike would I buy? Before the duel, I would have clearly said: the Storck Grix.2, but afterwards I changed my mind. His lead was narrow and was based more on my personal preference to still enjoy pushing myself. However, I can well imagine that things could be different in the future or that many health-orientated bikers might have a different opinion. In that case, the higher price would also be a good investment.
Storck eGrix vs Storck Grix.2
The Storck eGrix Pro in detail
- Drive: SRAM Force XPLR eTap AXS 1x12
- Wheelbase: 1013.3 mm (M)
- Wheels: Storck Zeitjaeger Platinum 40X
- Steering angle / seat tube: 71,1° / 72,5°
- Stack/Reach: 1,446
The Storck Grix.2 Comp in detail
- Drive: Shimano GRX RX820 1x12
- Wheelbase: 1013.3 mm (M)
- Wheels: DT Swiss GRC1400
- Steering angle / seat tube: 71,1° / 72,5°
- Stack/Reach: 1,446
