The Physics of Interference: Understanding Pedal Kickback

The Impact on the Trail

• Reduced Sensitivity: The suspension feels harsh because it is fighting drivetrain tension rather than absorbing the trail.
• Erratic Traction: When the suspension is restricted by kickback, the rear tire cannot maintain a consistent contact patch.
• Compromised Setup: Tuning a shock becomes a moving target when mechanical interference is constantly altering the effective spring rate and damping feel.

The Sidekick Solution

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Sidekick Architecture

The Pawl Pusher

Defining Deadband

Drag and Silence

• Faster Coasting: Reduced parasitic drag translates to better momentum retention in technical terrain.
• The Sound of Performance: You won’t hear a frantic swarm of bees. You will hear your tires searching for grip and the controlled movement of your suspension—the soundtrack of a bike working in perfect harmony with the trail.

*US20240157728A1 Hub system, method and device with adjustable deadband

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Kinematic Threshold

The Cumulative Toll

• Physical Fatigue: Your lower body is constantly absorbing micro-shocks as the cranks fight to rotate backward against your weight.
• Chassis Instability: When the suspension is seized by chain tension, the bike’s geometry becomes unpredictable. The rider is forced into a defensive, not aggressive, position.
• Mechanical Noise: Kickback contributes to chain slap and drivetrain vibration. This unwanted noise distracts the rider from the task of finding the limit.

Performance Unlocked

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Deadband is the period of hub operation after the freehub begins advancing but before the pawls start moving outward to engage the ratchet ring. Sidekick is the only hub in the world with a preset, adjustable deadband. 

In all traditional hubs, there is no deadband, only the period of rotation between the freehub and the hub shell where the pawls are between teeth on the ratchet, and the pawls are being pressed against the ratchet by the pawl springs at all times. Similarly for face-gear type hubs, there is only the space between engaged positions, and a spring presses the gears together at all times. These two systems describe the vast majority of hubs on the market today. 

In the Sidekick, a spring retracts the pawls away from the ratchet until they are required. As engagement (pedaling) begins, the pusher passes through the deadband before lifting the pawls towards the ratchet. 

With Sidekick’s adjustable deadband, the rider chooses the exact deadband desired to tune the hub response time and suspension benefit.

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Extremely low drag is the hallmark of the Sidekick hub, whisper-quiet, smooth operation is how it rolls! 

The primary pawls are always disengaged from the ratchet ring while coasting, so drag is significantly reduced compared to standard hub systems. The only spring-loaded pawl in the system is the pusher pawl, which uses a light-action spring to initiate the hub motion. 

The improvement in suspension performance makes a big difference in rolling speed. You’ll notice yourself carrying more speed in and out of features on the trail, as your suspension predictably operates at all times.

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Date: March 2026

Subject: Mechanical Efficiency and Drag Isolation of the e*thirteen Sidekick 2.0 Hub vs some key competitors

  Target Audience: Mechanical Engineers, Industry Professionals, and the Performance Cycling Public

1. Abstract

Bicycle drivetrain efficiency is traditionally measured by parasitic loss while pedaling. Freewheeling drag (coasting resistance) represents a significant opportunity for "marginal gains," particularly in gravity-oriented or technical disciplines. This paper details a comparative study using a custom-built precision spin-down stand to measure the drag torque () of several industry-leading MTB hubs. Results demonstrate that the e*thirteen Sidekick 2.0 provides a statistically significant reduction in drag compared to competitors, most notably the DT Swiss™ 350 DEG. 

Sidekick achieved a 51% reduction in total system drag in a complete wheel test, and an 88% reduction in an isolated freehub drag test compared to its primary kickback-reducing competitor.

2. Introduction

Historically, mountain bike hub development has prioritized rapid freewheel engagement and minimal weight as the primary metrics of performance. However, these mechanical solutions often introduce parasitic drag as a byproduct. The e*thirteen Sidekick 2.0 was engineered with a patented freehub mechanism designed to decouple the freehub during coasting and add a fixed deadband during suspension actuation and chain movement. This freehub also theoretically minimizes internal friction while coasting. To validate these claims, we developed a "Fixed-Interval" spin-down test to quantify energy loss. This methodology isolates bearing, seal, and ratchet friction, providing a clear comparison of hub coasting efficiency between different manufacturers' products.

3. Apparatus and Methodology

3.1 Test Stand

• The test apparatus is constructed from a rigid 80/20 aluminum extrusion frame with a steel wheel support frame attached.
• Axle Interface: A standard 12mm thru-axle is used, threaded into a UDH derailleur hanger mounted to the frame.
• Preload Control: The thru-axle was torqued to exactly 8 N-m for every trial to ensure consistent bearing contact and seal compression.
• Data Acquisition (DAQ): An Arduino-based system captures timing data via a 12-point tone wheel (30° resolution) detected by an inductive sensor.
• For Hub-only testing, steel screws were installed at 12 regular points on the 15lb weight.

3.2 Environmental and Mechanical Controls

• Thermal Consistency: Tests were conducted at 68°F (20°C) to maintain consistent grease viscosity.
• Break-in Procedure: Hubs underwent a standardized break-in. An axle was installed in each hub, tightened to 12Nm, and spun for 5 minutes using a 1500 RPM hand drill to settle factory grease and seat seals.
• Trial Density: Each hub was subjected to three consecutive runs; results represent the mean of these trials.
• Competitor Hubs were purchased from an online retail channel in aftermarket packaging.

3.3 Hub-Only "System Simulation" Testing

To isolate internal mechanical drag from aerodynamic variables while simulating a coasting wheel, a 15 lb (33kg) rubber weighted plate (450mm diameter) was attached directly to the disc brake tabs of an unlaced hub.

• Dominant Inertia: The plate's Mass Moment of Inertia (MMOI) was calculated at , allowing for high-resolution measurement of drag torque .
• The mass and moment of inertia of each hub was neglected for the purposes of this test, as all hubs tested weighed between 280g and 350g, so the moment of inertia of the plate dominates the small contribution from each hub.
• Fixed-Interval Window: The DAQ begins recording at 80 RPM and stops at 20 RPM.

Two specific test modes were utilized:

• Freewheeling Simulation (Hub Shell Turning): The 15lb weight is attached to the hub shell (via disc tabs) while the freehub body is held stationary. This simulates a bicycle wheel coasting, where the hub shell and its bearings are rotating relative to a fixed drivetrain.
• All-Bearing Drag (No Ratchet): The hub is spun such that there is no relative motion between the freehub and the shell. This test bypasses the ratchet mechanism to isolate the rolling resistance of all internal bearings and endcap seals. This is a loose analog to the rolling resistance of the hub during pedaling.

3.4 Complete Wheel System Test

This configuration evaluates the hub as part of a complete wheel assembly Unlike the isolated hub tests; this mode captures the total system resistance encountered during on-trail coasting. For this test, the wheel is spun up and the freehub body is held stationary.

When the freehub is ratcheting in this configuration:

• Active Components: The drive-mechanism (ratchet/pawls) is actively ratcheting due to the relative velocity between the two bodies.
• Bearing Rotation: The primary hub shell bearings are rotating; freehub bearings are stationary.
• Seal Drag: Only the non-drive-side endcap seal and freehub-to-hub-shell seal are active.
• System Inertia: The Mass Moment of Inertia () of the hub shell rim, spokes, and nipples is calculated using the period of oscillation from a trifilar pendulum.

4. Discussion of Test Limitations

• No-Load Condition: These results reflect a "zero-load" state (or in the case of the weight, a nearly no-load condition). While this does not account for radial rider load, it serves as a sensitive baseline for bearing, seal, and ratchet efficiency.
• Aerodynamic Residuals: For Hub-only testing, aerodynamic drag is minimized by the plate's profile but not eliminated. For complete wheel testing, the aero drag coefficient is similar between wheels. However, since aerodynamic drag accumulates more as test duration increases, it actually "punishes" more efficient hubs (which spin longer), making our findings regarding the Sidekick's efficiency conservative for that test.
• Grease Temperature: Some drift in timed results was observed as consecutive tests were performed. This was attributed to bearing grease warming over consecutive runs. If a large discrepancy was observed, additional runs were measured, and the first run discarded, until consistent results were achieved for 3 consecutive runs.
• Axial Preload Sensitivity: While a standardized 8 N-m torque was used for the thru-axle, different bearing architectures (e.g., angular contact vs. radial deep groove) may respond differently to axial loading. This test does not account for the efficiency changes that might occur under variable thru-axle setups.
• Break-in: A cursory break-in was performed on each hub. This break-in did appear to make a difference in the test hubs, as measured by tests before and after break-in. It is reasonable to assume that further break-in could improve the results of some of the hubs tested, but the broad conclusions should stand.

5. Results & Analysis

5.1 Test A: Freewheeling Drag (Hub Shell Rotating)

This test simulates the resistance a rider feels while coasting. The 15lb mass is attached to the hub shell, and the freehub is held stationary.

Longer Spin Down Time = Lower Drag Torque / Torque values expressed in mN·m = milli-Newton·meters

5.2 Test B: All-Bearing Drag (No Ratcheting)

This test evaluates the baseline quality of the bearings and seals when the drive mechanism is bypassed.

5.3 Complete Wheel System Test

To simulate real-world usage, tests were performed on fully assembled wheels.

5.4 Data Variance and Technical Scope

Friction in rotating assemblies is subject to variations in grease distribution, seal elasticity, and manufacturing tolerances. Furthermore, every hub in this test would undergo significant break-in over hundreds of miles of riding, which cannot be fully replicated by an accelerated drill break-in. The data presented here is intended to draw a broad comparative conclusion regarding hub ratchet designs. While absolute numbers may vary across different testing environments, the relative performance delta between the e*thirteen Sidekick 2.0 and its competitors is robust and serves as a reliable indicator of mechanical efficiency.

6. Real-World Application: Calculated Power Dissipation (Watts)

At a coasting speed of 30 km/h (approx. 240 RPM or 25.13 rad/s for a 29" wheel), the mechanical power dissipated by the hub during freewheeling is estimated at:

The "Marginal Gain": The 1.37 Watt difference between the Sidekick and the DT Swiss™ DEG represents energy lost constantly while coasting. Over a long technical descent, this cumulative loss saps potential energy and reduces conserved speed.

7. Conclusion

The e*thirteen Sidekick 2.0 achieves an 88.5% reduction in freewheeling drag compared to the DT Swiss™ 350 DEG DF. By successfully decoupling the drive mechanism during coasting, it achieves the lowest in its class. Competitors attempt to solve pedal kickback but do so at a significant cost to mechanical efficiency. The Sidekick 2.0 is the current benchmark for high-efficiency, momentum-preserving hub design.

8. Appendix: Experimental Setup & Instrumentation

8.1 Precision Spin-Down Stand

8.2 Hub-Only Test Configuration

8.3 Complete Wheel Test Setup

8.4 Trifilar Pendulum Calibration

8.5 Data Acquisition Hardware

9. Trademarks and Disclaimers

• DT Swiss, 350, DEG™, and DF™, are trademarks of DT Swiss AG.
• Hope™ and Pro 5™ are trademarks of Hope Technology Ltd.
• RaceFace™ and Vault™ are trademarks of Fox Factory Holding Corp.
• Industry Nine™, I9, and Hydra™ are trademarks of Industry Nine, Inc.
• e*thirteen and Sidekick are trademarks of The Hive Global, Incorporated.

All trademarks, service marks, and company names mentioned in this document are the property of their respective owners. These products were chosen specifically as the primary high-performance market competitors to the Sidekick hub. All trademarks are used in this document for comparative and informational purposes only and do not imply any affiliation with, sponsorship, or endorsement by the respective trademark owners.

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We recommend that everyone tests their Sidekick hub in all deadband settings, to find the perfect set up for their bike, personal riding style, and terrain. 

Shorter travel bikes in less extreme terrain may suffer less from pedal kickback and prioritize the improved pedaling efficiency in technical climbs of a shorter deadband. Longer travel bikes,

especially in steep, rough terrain often exhibit higher levels of pedal kickback, therefore benefiting most from the longer deadband. 

Inversely, in most suspension systems, bikes with kinematics prioritizing a high level of anti-squat (resistance to compression during pedaling), will also have higher levels of pedal kickback. This makes sense as anti-squat works by using chain force to extend the suspension, countering the squatting motion. Anti-squat in bicycles is about enhancing pedaling efficiency and maintaining traction. So, many bikes that are designed to pedal exceptionally efficiently, will often experience more pedal kickback when traveling at low to moderate speeds, over rough terrain. 

The Sidekick hub seamlessly switches between reducing or eliminating pedal kickback and providing the designed amount of anti-squat, without the rider even knowing. 

“In terms of deadband, I use the middle setting which is 15°. To me it’s a good compromise between less kickback, lots of comfort and traction, but also good reactivity if I have to throw a pedal-kick before a drop or anything like this.” 

– Remy Metailler (Freeride Legend)

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The reason is consistency. With the Sidekick, the pusher will provide a guaranteed amount of engagement deadband. Low engagement hubs vary in the degrees to engage each time, depending on where the pawls were to the teeth of the ratchet ring the engagement speed could be anywhere from close to zero degrees up to the maximum number of degrees the system offers. This increases the unpredictability of pedal kickback’s effect on suspension. The other advantage is that the degrees of freedom can be easily adjusted with the Sidekick design. 

Descending on a mountain bike at 15mph (~25kph) a rear hub and 29” rim rotates at 170rpm or nearly 3 times per second. A hub with a 18 degree engagement angle (20 engagement points), could potentially engage over 60 times per second! The likelihood of having pedal kickback in this scenario is extremely high and only increases with hubs that engage faster. 

Faster engagement may be a selling point of some hubs, but it definitely does not lead to better suspension performance. A hub with 1 degree engagement (360 engagement points) can potentially engage over 1000 times per second, practically ensuring pedal kickback and severely limiting suspension performance.

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Performance - Sidekick hubs decouple the drivetrain from the suspension eliminating kickback at its source. Crank mounted anti-kickback solutions for example simply mask the kickback effects for the rider while Sidekick eliminates it from the source. 

Reliability - The internals of the Sidekick are shielded from the elements (no creaking!) as they are located inside the rear hub. 

Weight - There is a very low weight penalty between Sidekick and traditional hubs, adding a fraction of the weight of other products. 

Cost - Sidekick doubles as a high-quality rear hub and anti-kickback system. Other products are additional components that add significant cost. 

Free Speed - The added benefit of extremely low drag in Sidekick hubs means you’ll accelerate faster and carry speed better. 

Crisp Engagement - unlike the “elastic” feeling engagement common in some other hubs and anti-kickback devices, Sidekick’s engagement feeling is reliably crisp and familiar. 

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We expect that the most common application for Sidekick will be on bikes with 130mm+ or more of travel.

While most of our development and testing was focused on longer travel Enduro and DH bikes, we did also test on shorter travel trail and all-mountain bikes. Both the improved suspension performance and increased rolling speed are notable on all platforms. However, as you move to shorter travel XC and trail bikes, the increased weight of Sidekick and slightly slower engagement do become more of a consideration. 

We'd strongly recommend Sidekick for any rider who is focused on improving their speed and comfort while reducing their fatigue on the downhills, regardless of bike travel.

If you are on the fence about adding Sidekick to your short travel bike, consider the following:

Initial feedback from riders who have used Sidekick on shorter travel bikes is really positive; with most riders saying they feel like they are getting better use of the limited amount of travel they do have. In this application, the shortest 12 degree setting for the pusher would probably be the most appropriate. The potential drawbacks for some riders with shorter travel bikes are that (1) Sidekick is a bit heavier than a traditional hub and (2) potentially slower engagement may be less ideal for technical climbing sections where a lot pauses in pedal strokes are occurring. In short, if you setup your short travel bike leaning more towards the current "downcountry" trend, we would expect you would really like and benefit from sidekick. Whereas if you setup your short travel bike leaning more towards "XC Race", the engagment speed and weight penalty may be more of a consideration. 

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Yes, Sidekick hubs are compatible with all Class-1 e-bikes; there are additional benefits for e-bike riders! 

E-bikes experience the same kickback effect as any full-suspension bike, the difference being that spikes in chain tension will be loaded into the motor, rather than feeding directly into the cranks and pedals. While this chain force typically wouldn’t be felt by the rider at the pedals, the negative effects on suspension performance are the same. 

Since e-bike motors operate with a torque sensor, the rider can use the highest deadband setting and still experience quick engagement of the rear hub. The motor will turn the chainring faster than the rider turns the cranks, more quickly taking up any slack in the chain. 

As an added benefit, chain vibration can cause a significant amount of noise with certain ebike motors, such as Shimano EP8 or Bosch CX motors with internal counter-acting clutches. On these bikes, Sidekick can significantly reduce or even eliminate this noise.

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Sidekick Has Benefits for All

Yes, even if you're not a professional downhill racer, you can still benefit from Sidekick hubs. Sidekick hubs improve suspension performance for riders of all skill levels by eliminating pedal kickback and reducing chain vibration. This results in:

• Increased comfort and control: Whether you're riding rough terrain or just looking for a smoother ride, Sidekick can help. You'll feel less fatigued, especially on longer rides.
• Improved traction: With the drivetrain disengaged from the suspension, your bike can react more effectively to bumps, giving you more grip on the trail.
• Faster free speed: Reduced drag in the freehub means you'll carry more speed through smooth and rough sections.
• Quieter ride: Sidekick hubs are nearly silent, allowing you to enjoy the sounds of the trail.

Sidekick hubs are designed for a wide range of bikes, including:

• Long-travel Enduro and DH bikes
• Shorter-travel Trail or All-Mountain bikes
• Class 1 e-bikes

Ultimately, if you want to enhance your ride experience with a more comfortable, controlled, and efficient ride, Sidekick hubs are worth a look!

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 Estimated aftermarket availablity date: Mid May, 2026  

Pedal kickback degrades suspension performance even when you can't feel it. Chain tension from suspension movement pulls against the pedals, robbing traction and adding fatigue. Sidekick is the award-winning hub that fully disconnects the drivetrain while coasting, eliminating kickback at the source rather than just damping it. Pinkbike named it Innovation of the Year, calling it "the most elegant take on chain-force mitigation we've seen to date."

But Sidekick does more than eliminate kickback. Traditional hubs create drag and noise when coasting. Sidekick's pawls disengage completely, so the hub spins like a front wheel with zero resistance. You carry more speed through rough sections without losing momentum. And instead of the angry-bee ratchet of a conventional freehub, you hear your tires and the trail. Riders consistently call the silence one of their favorite features.

The Design & Innovation Award recognized Sidekick for delivering "noticeably more responsive suspension, fewer vibrations, and significantly reduced rider fatigue." BikeRadar found it made "a marked difference to suspension performance" with "seemingly more time to think about your lines and body position." MBR said it feels "like riding chainless" with the rear wheel tracking better under braking.

Adjustable deadband lets you tune engagement to your bike and riding style: 12°, 15°, or 18°. Tool-free service means anyone can rebuild the hub in minutes without specialized equipment.

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Flux is laterally stiff, giving precise handling. The magic happens at the tire contact patch, where the rim deflects locally, absorbing chatter that would otherwise transfer to the suspension and eventually onto the rider.

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Previous generations of e*thirteen Plus and Race wheels prioritize exceptional strength and durability, making them legendary on the World Cup as the only wheels that perform race after race on the world’s toughest tracks. While these rims provide riders with the confidence they need to push their limits, they are also very stiff, which means a fast and precise wheel, but also one that transmits a lot of trail feedback to the rider. 

e*thirteen took our rim game to the next level by addressing the desires of our pro riders and consumers, to reach the strength and resilience benchmarks set by LG1 and Grappler rims, while increasing compliance. Compliance in wheels increases comfort, reduces rider fatigue, and improves traction and tracking by decreasing wheel deflection. 

Grappler Flux rims and wheels were engineered with Ride Dynamics as a priority. They strike a good balance between durability, the lateral stiffness needed for precise control, and the ideal level of vertical compliance required to create a more comfortable wheel that improves performance. Rebound energy was also tuned to blend the damping quality that takes the sting out of impacts, with a dynamic ride feel that keeps them lively out of compressions. 

Several competitors have also claimed compliance in rims and some have hit the sweet spot. However, no other wheels we have tested can weigh up to e*thirteen Grappler Flux rims for performance-enhancing compliance and strength.

Other common issues with compliant rim designs are excessive flexibleness or the “tire rollover” feeling when rims twist under load, such as pushing into corners. It was paramount for e*thirteen to maintain ride quality in every way with the new Grappler Flux. After multiple seasons of testing on the World Cup, we feel the Grappler Flux ticks all the boxes. The proof is in the ride!

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Flux is the result of learning from many seasons of World Cup Downhill racing. First, we built in the toughness and won World Cup overalls with the LG1 Race Carbon DH wheels. Next, we embarked on engineering a rim as tough, but with the compliance being asked for by our riders.

Riders and racers can expect Flux rims to be every bit as strong and durable as our previous, highly regarded rims. To back this up, we offer a "no questions asked" Lifetime Guarantee on all carbon rims and a 5 year manufacture defects warranty on alloy rims for the original owners. You can find more information on our warranty here. 

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At e*thirteen, we test our wheels rigorously to ensure they meet the highest performance and durability standards. In conjunction with real world testing, we perform a series of specialized assessments designed to simulate real-world conditions and provide detailed insights into how our wheels perform under stress. 

Impact Testing

Our Rim Impact Test measures the energy our rims can withstand before failure, ensuring that they fail in a controlled manner that still allows riders to continue their journey safely. 

Deflection Testing

We aconduct Vertical and Angled Rim Deflection Tests to gauge a wheel's ride characteristics, assessing how much the wheel flexes under different angles to optimize for both comfort and control.

Rebound Testing 

Our Rebound Test quantifies how much impact energy is returned by the wheel, helping us fine-tune the dynamic feel of our products. 

Through these rigorous tests combined with extensive real world testing by both our internal test team and our sponsored World Cup athletes, we ensure that every e*thirteen wheel delivers the reliability and performance that riders expect.

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e*thirteen rims are ETRTO compliant and feature hookless flanges which have been tuned over the past decade to deliver “set and forget” tubeless performance, excellent tire retention, and resilience to damage from impacts. 

The compliance engineered into Grappler Flux rims does not affect tire fit or retention. Quite the opposite. With the rim and tire working together, traction is increased, and tire retention is maximized. 

The 30mm inner width of Grappler Flux rims are best suited for 2.3”-2.6” tires, optimizing tire profiles for traction and speed, and allowing for a wide range of tire pressures. While they are compatible with tires slightly wider or narrower than this, there may be compromises to tire stability or profile.

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Sidekick hubs require routine maintenance similar to any other high-performance hub, including periodic cleaning and greasing. e*thirteen provides clear service intervals and detailed instructions to ensure your Sidekick Hub performs at its best. Maintenance is straightforward, and adjustments like deadband tuning can be done without tools, making upkeep quick and hassle-free.

“The Sidekick has been super reliable and easy to work on. Aside from changing bearings, maintenance and adjustments are all tool-free. That includes adjusting the deadband engagement setting to accommodate different tracks or suspension kinematics.” – Ryan Thom (UR Team Head Mechanic)

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