e*thirteen Sidekick Longterm review and CoPilot feedback
Reading time: 10 – 11 minutes
We announced it and kicked it off at the Freiburg Bike Festival: CoPilot. Anyone from the biking community who’s interested is welcome to join us for testing. This way, test gear becomes available to a wider audience, and we broaden the feedback in terms of riding styles, rider weight, trails, and bikes. Now it’s time to sum up all the impressions from the long-term test of the e*thirteen Sidekick hub. Does everyone notice a positive effect when it comes to pedal kickback?
Who tested and how and where?
We already explained how the hub works in detail in our initial review. The e*thirteen Sidekick hub is designed to counteract what's known as pedal kickback. Altogether, we had the chance to ride with ten different testers. The tests took place under real-world conditions across various regions — including Freiburg, Heidelberg, the Palatinate, Saalbach, the Odenwald, and the Spessart. Rider weights ranged from 55 to 105 kg (120 to 230 lbs), and the bikes covered everything from trail and enduro to freeride and full-on DJI-powered e-MTBs. The testing also included blind tests.
Here are the wheelsets we used:
Grappler Sidekick Flux Carbon – 157 mm in 29″
Grappler Sidekick Flux Aluminium – 148 mm in 29″
Grappler Sidekick Flux Aluminium – 148 mm in 27,5″
At the CoPilot test event in Freiburg, the trails threw everything they had at us to offer the widest possible range of conditions. From bone-dry, natural trails on the first day to slick and muddy terrain on the second, all the way to man-made jumps — we had it all.
Some testers were riding on very slippery trails...
…while others took the hub under heavy impact on dry trails.
90% solid impression and the blind test
Our testers didn’t always know which wheelset we were installing on their bikes. One out of ten couldn't notice any real difference compared to their DT370 hub. The remaining nine confirmed a smoother and more stable riding experience.
Things got particularly interesting during the blind tests. On joint CoPilot rides, we adjusted the engagement angle without revealing whether we had increased or decreased the freeplay. In these scenarios, not all testers could clearly pinpoint what had changed. Three out of ten were unsure and would have had to guess. However, even the uncertain testers reported that, regardless of the setting, they felt more confident on the trail compared to a standard hub.
We switched things up on the trail.
And collected slomotion video to discuss with the CoPilot’s.
CoPilot’s reflected on the riding feel.
The longer the testing period was for each rider and the more they played with the settings, the clearer they could identify the different engagement levels.
The biggest "Aha!" moment came when switching back to a rear wheel without the Sidekick system. The ride was then perceived as much more unsettled, except for one tester who didn’t notice any difference compared to the Sidekick. Nine out of ten CoPilots consider a system like Sidekick to be a useful feature.
"On a straight section with plenty of consecutive bumps, it doesn’t rattle as much on the trail bike. You stay on your pedals and can ride with more confidence – this enables you to go faster, and the bike feels more stable. In corners, there’s more security because the smoother ride allows you to focus better on the turns." – Jessy
It’s important to note that not every bike feels the same when it comes to pedal kickback. Some bikes feel the Sidekick effect more strongly, while others experience it less. Particularly on bikes with less than 150 mm of travel, there was a noticeable improvement in ride smoothness. If you’re unsure whether it’s worth it for your bike, you should take it for a test ride.
Testpilot 50/50 – CoPilot 100 %
In our first review, the test riders immediately noticed the difference in freeplay when directly comparing the Industry Nine Hydra hub with its very direct engagement. Yannick and Jens had different opinions on this. While Jens needed a longer adjustment period coming from the i9 Hydra, Yannick had only a brief adaptation phase.
None of the ten CoPilots were riding a bike with a very tightly meshed hub, and none found the increased free spin before engagement of the Sidekick hub to be bothersome.
12, 15, or 18 degrees? The freeplay is adjustable. Every tester was able to get used to it. In the end, the gap was never considered as a downside.
Sidekick and E-Bike
The CoPilot feedback on the hub, which was installed in an Amflow with a DJI motor, was enthusiastic:
"Almost like riding chainless. I barely noticed the freeplay. I can only explain this by the pre-engagement of the software. This could really be a killer combo." – Romero
It’s important to note that comparable systems for the chainring aren’t widely available yet. Only Ochain offers a similar system. Rimpact is currently asking users on their website which interface they prefer and would produce accordingly based on demand.
e*thirteen already allows the system to be used and, importantly, swapped between bikes, with full compatibility for all e-bike motors.
Going rather E? In the Amflow you can go hard with the Sidekick system.
Wear?
When the time span and the duration of stress are long enough, something will always give way eventually. At Testpilot, we want to highlight these things with full transparency and identify possible solutions.
Out of the three Sidekick rear wheels in long-term testing, two performed completely without issue. One was used in an Amflow e-bike for a while and later in a RAAW Madonna. This wheelset was subjected to some heavy strain. In a bike park scenario with speeds over 50 km/h, ankle-deep braking waves, and an fully hauled berm, so much force and torsion were applied that the spring ring of the pawl mechanism momentarily got caught. As a result, the hub lost engagement, and the rider couldn’t pedal anymore, only coast.
After continuing down the trail, the spring automatically reset, and the hub functioned as usual again. Upon inquiry with e*thirteen, we received the following feedback:
After a thorough inspection of the affected wheel in our facility, we can confirm, as the test riders had suspected, that the spring ring was the cause of the temporary malfunction.
For the proper functioning of the system, the correct positioning of the spring ring is crucial. In this case, it had momentarily come loose, causing the described issues.
While this did not result in a major failure of the hub, we obviously want to ensure the flawless operation of the Sidekick hub under any extreme conditions. We are currently reviewing a redesign of the spring ring and will test it extensively. Any necessary evolutions of the components will be immediately integrated into production and made available to users of the Sidekick hub. Affected riders are encouraged to reach out to us directly:
Phone: +49 (0)861-21177145
– e*thirteen
Considering that all the wheels were equipped with Enduro-casing tires, it's impressive that there were no damages or dents on the rims. Neither aluminum nor carbon showed any weakness, aside from a few scratches. Absolutely solid!
On the carbon 29-inch rear wheel, the spoke tension decreased after 7 months. We noticed increased lateral flex of the rim while riding. Why is this important for all carbon rims, and why should it be mentioned in general?
A carbon rim is inherently much stiffer in construction than its aluminum counterpart. While with aluminum, some lateral wobble may become visible, carbon remains less noticeable. During a visual inspection, the wheel often still appears very straight, even if the spoke tension is too low. It’s important to occasionally check the tension. Pressing two spokes together with your hand is not a substitute for a spoke tension meter – but it can provide clues, and even a layperson can detect completely loose spokes. Those who take care of their wheels in this way will enjoy them for longer and can prevent potential damage. After increasing the spoke tension, the Sidekick-Flux rear wheel ran flawlessly again, and cornering was as precise as on day one.
The facts
Impressive Performance: 9 out of 10 testers confirmed a smoother and more stable riding feel, with greater confidence on rough lines. The effect became especially noticeable when switching back to a standard hub, which almost all testers found significantly "bumpier."
Wide Compatibility: The system works flawlessly on trail bikes, enduros, and was particularly impressive when paired with high-performance e-bikes, where the riding feel was described as “almost like riding chainless.” e*thirteen explicitly approves the hub for e-bikes.
Robust Build: Despite extreme stress, there was no permanent damage to the rims (both aluminum and carbon). A temporary issue with the pawl spring in an extreme situation was resolved, and the hub functioned perfectly afterwards.
Service: A key point for carbon fans is monitoring spoke tension — this applies to all wheels. After 7 months, we noticed that the spokes needed to be tightened. The wheel continued to run flawlessly after that.
e*thirteen Grappler Tires: While the main focus of the test was the hub, the Grappler tires deserve a mention. Although they require a bit more effort on forest path uphills, they reward with great grip on the descents. None of the testers had a single flat or puncture. In terms of wear, they wore down a bit faster than a Continental in a soft compound, but even then, the wear was still within moderate limits.
Conclusion: e*thirteen Sidekick longterm test
The principle of the e*thirteen Sidekick convinced us in the long-term test, and the CoPilots as well. Pedal kickback will increasingly be an important issue, and manufacturers will need to offer solutions for it. The Sidekick is not a gimmick but a valuable upgrade. Whether it’s a trail bike, enduro, or even an e-bike, every category benefits, making you safer on the trail. For those who opt for the Flux carbon rims, you’ll get even more ride quality and grip, especially on cross-riding.
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Autor – Jens Staudt
Größe: 191 cm
Gewicht: 87 kg
Fahrstil: Mit seinem Race-Hintergrund sind die Linien geplant, auch wenn es mal rumpelt. Wenn möglich, werden Passagen übersprungen. Die ganze Breite eines Trails sollte man nutzen. Andere würden sagen – kompromisslos.
Motivation: Ein Produkt sollte sorgenfrei und möglichst lange funktionieren. Wenn man weniger schrauben muss, kann man mehr fahren. Er bastelt gerne und schaut, wie das Bike noch optimiert werden kann.
Autor – Yannick Noll
Größe: 178 cm
Gewicht: 75 kg
Fahrstil: Als ehemaliger Racer darf es gerne schnell und flüssig sein. Größere Sprünge und steile Rampen dürfen aber auch nicht fehlen. Das Bike ist etwas straffer und schneller abgestimmt, dass es entsprechend schnell auf Input vom Fahrer reagiert.
Motivation: Es soll Spaß machen. Ein Bike sollte nicht langweilig, alles platt bügeln. Der Charakter darf etwas lebendiger sein. Bei der Abstimmung, wie auch beim Fahrstil. Das Produkt sollte haltbar sein und auch auf längeren Biketrips sorgenfrei funktionieren.