Pedal kickback has long been recognised as a performance killer – for some more than others. American component manufacturer E*thirteen claims to have found the solution with their new Sidekick hub. But does the system work, and is it really worth spending € 500?
Pedal kickback affects the performance of mountain bikes, and can have an influence on the way we ride – even if some might not be entirely sure what pedal kickback is. Aaron Gwin’s run at the 2015 Downhill World Cup in Leogang is the perfect example of how it could potentially impact your bike’s performance. Despite breaking his chain, he clocked the fastest time on the hill, which suggests that the absence of pedal kickback may have played a crucial role. Pedal kickback occurs when the distance between the chainring and the cassette grows as the suspension compresses. This pulls on the chain and causes the front pedal to kick upwards, creating resistance against your pedalling. This reduces the efficiency of the rear suspension, decreases grip, and uses up additional energy as you have to counteract the sudden pedal movements. A detailed explanation of how pedal kickback occurs can be found below.
Founded in 2001 in Boston, E*thirteen made a name for themselves with their chain guides, especially in the racing scene. Now, the American manufacturer claims to have found a solution to pedal kickback. The new E*thirteen Sidekick Hub is meant to make you feel as if you were riding chainless. We’ve put the hub to the test to see if that’s true. One important note: pedal kickback affects different bikes in different ways, depending on the rear suspension design.
What exactly is pedal kickback?
To understand how the E*thirteen Sidekick Hub works, we’re going to explain what pedal kickback is and when it occurs.
In a few words: if you lift a bike off the ground and drop it, causing the suspension to compress, there’s a good chance that the pedals will rotate backwards. This is pedal kickback.
But let’s start from the beginning: A bike’s rear suspension isn’t just the sum of its parts, but rather a dynamic and very complex system. If you’d like to dive deeper into this topic, take a closer look at our comprehensive guide to kinematics, anti-squat and co. article. In general, any component that has an influence on chain forces or alters the behaviour of the rear suspension will have different effects depending on the bike’s design, shock, gearing, and many other factors. To illustrate, let’s consider the simplest rear suspension design: the single pivot. When the swingarm on this sort of bike pivots upwards after an impact, it rotates around the main pivot point. If this pivot is positioned in the bottom bracket area, the distance between the cassette and the chainring remains consistent throughout the suspension travel.
If the main pivot is not positioned in the bottom bracket area – as is the case with most bikes – the distance between the chainring and cassette changes as the swingarm rotates upwards most cases it increases, thus putting tension on the chain, which causes the chainring and pedals to rotate backwards. The result is an unpleasant feeling, as though the pedals are being pulled back. It’s important to note that pedal kickback is only noticeable when the freehub is engaged, either while pedalling or when the suspension compresses faster than the rear wheel rotates. At higher speeds, when the rear wheel spins faster than the suspension compresses, the hub rotates so quickly that the freehub doesn’t engage, and no tension is applied to the chain. The backward rotation of the cranks due to pedal kickback is measured in degrees.
Almost all suspension designs are affected by pedal kickback – some more than others. The extent to which your bike is affected depends on the rear suspension design, your choice of gears, and how far into the travel the suspension compresses. Some suspension designs, like high-pivot bikes, experience significant chain growth, but idler pulleys can almost entirely eliminate kickback. Other designs, like single-pivot bikes with a high main pivot, are notorious for substantial chainstay growth. On such bikes, the cranks can rotate backwards by up to 35° in a 32/50 gear ratio!
In general, pedal kickback is most pronounced in the lower gears and decreases as you shift to smaller cogs, i.e., higher gears. The trend towards smaller chainrings and wider cassette ranges has further amplified pedal kickback in the lower gears.
How does the E*thirteen Sidekick Hub work?
The E*thirteen Sidekick Hub is similar to a conventional pawl freehub. Three pawls engage a toothed ratchet to transfer power to the wheel. The difference with this hub is that the pawls remain inactive until engaged, making the hub nearly silent except for a faint click.
In conventional hubs, when you pedal, the freehub engages at a certain point, depending on the rear hub’s engagement angle. The lower the engagement angle, the less crank movement is required before power is transferred. With the E*thirteen Sidekick Hub, it works differently: A “Pawl Pusher” pushes the previously inactive pawls into the ratchet, allowing you to pedal.
Before power is transferred, there’s a deadband where the Pawl Pusher rotates before lifting the pawls. The distance between the pusher and the pawls is adjustable. This allows the freehub body to move by a certain angle relative to the pawl pusher before the pawls engage. This deadband compensates for the chain tension caused by suspension compression, essentially giving the chain room to move. This prevents pedal kickback.
This also means that, depending on the set amount of deadband, you’ll encounter no resistance before feeling engagement when you start pedalling. Sometimes the angle can be 30°, other times only 5°. To ensure the deadband remains consistent, the Pawl Pusher has a timing pawl. This lightly sprung pawl sits in the toothed ratchet and produces a faint clicking sound from the hub – only audible when everything around you is completely quiet.
You can adjust the deadband to 12°, 15°, or 18° depending on your needs and preferences. To do this, simply unscrew the cover on the non-drive side of the hub and remove the axle from the hub shell along with the cassette. The pawls and the red pawl pusher, marked with the three adjustment angles, will be revealed. Now, just lift the Pawl Pusher, position it at the desired setting, and slide it back onto the axle – done. The adjustment is quick and tool-free, and can even be done directly on the trail. However, be careful: the inside of the hub is well-greased, so make sure not to let any dirt enter the system, or handle important documents with greasy fingers afterwards!
Variants of the E*thirteen Sidekick Hub
The rear hub comes in two colours: sterling silver and black. E*thirteen also offer the new Grappler Flux downhill and enduro wheelsets with or without the Sidekick system, in both alloy and carbon variants. Additionally, the Sylvan All-Mountain wheels come with the Sidekick Hub ex-works.
Of course, there’s also a matching front hub for the E*thirteen Sidekick rear hub. According to the manufacturer, it weighs 196 g and is available in black and sterling silver for € 169,95. Additionally, there is a Sidekick SL version of the front hub, which E*thirteen lists at 132 g.
The Grappler Sidekick Flux Enduro wheelset is available in 29″ for the front and either 27.5″ or 29″ for the rear. For the carbon set, you’ll have to fork out € 799.95 for the front wheel and € 1,199.95 for the rear. The aluminium version is more affordable: € 379,95 for the front and € 649.95 for the rear.
The downhill version of the Grappler Sidekick Flux wheelset is available in 29″ for the front and either 27.5″ or 29″ for the rear. The carbon set consists of a front wheel priced at € 849.95 and a rear wheel, depending on size, at € 1,349.95 or € 1,499.95. The aluminium version is priced at € 379.95 for the front and € 659.95 or € 799.95 for the rear.
There’s also the Sylvan All-Mountain Flux wheelset with Sidekick hub, in 29″ for the front and either 27.5″ or 29″ for the rear. For the carbon version, you’ll have to pay € 779.95 for the front wheel and € 1,119.95 for the rear. The aluminium version is more affordable at € 379.95 for the front and € 629.95 for the rear.
The E*thirteen Sidekick hub on the trail
We installed the hub on various test bikes and took it out on our local trails and in different bike parks.
The first thing to get used to is that when you start pedalling, there’s an initial gap with no resistance, so the power transfer kicks in slightly later. With some practice, you can consciously bridge this gap by applying power to the pedals more gradually. However, in technical uphill sections, it’s hard to make small, precise pedal strokes, especially on an e-bike. When climbing and cruising, on the other hand, the hub feels like a conventional hub.
With e-bikes, the motor’s power is also transferred with some delay due to the free movement, which has its pros and cons depending on the motor system. The hub essentially works against the pre-set response time of the motor, so when the motor kicks in, the extra energy delivered by the deadband can cause a sudden surge of power – something to be mindful of.
The perks of the Sidekick hub are clearly noticeable on the way down. In fast sections, where you usually ride in outer gears and the freewheel mechanism doesn’t engage, pedal kickback is less noticeable. However, you can already tell here that the bike feels smoother and more composed. The E*thirteen Sidekick hub really comes into its own when you blast through a rock garden and slam on the brakes. The freehub’s deadband also has its perks on fast root carpets, drops and steps, where it allows the shock to work more efficiently, thus ensuring a more composed ride feeling and requiring less physical effort. The bike is noticeably firmer on the trail, which improves grip and the feeling of safety.
The ideal setting for the E*thirteen Sidekick hub depends heavily on the bike, the suspension design and the components. Nevertheless, we never felt the need to set the free travel to more than 18° – depending on the bike, it may even be a little lower. In this respect, the Ochain system is ahead, as it can be adjusted down to 4°, while E*thirteen’s 12° is the lower limit.
Who should take a closer look at the E*thirteen Sidekick hub?
If you’re struggling with pedal kickback, the E*thirteen Sidekick hub offers an effective solution, as it eradicates the problem at the root. The system shows its strengths above all with drops and under braking in nasty rock gardens, ensuring better traction and a more composed ride. Flat pedal riders especially will benefit from the system, as it offers more stability on the pedals and reduces slippage caused by vibrations. Overall, all riders will appreciate the reduced vibrations on the pedals.
However, the Sidekick hub also dampens the feedback from the trail, which might be an issue for some riders. For those who don’t mind, the E*thirteen Sidekick hub is a great way to improve your skills or PBs on the trail, as it optimises the performance of both the suspension and the whole bike. The slightly increased free movement in the cranks does take some getting used, but this is only a mater of time.
Conclusion about the E*thirteen Sidekick hub
The E*thirteen Sidekick hub is a smart solution for pedal kickback, offering more control and traction in many trail sections. All riders benefit from increased composure, as the vibrations in the pedals are reduced. While the increased deadband when pedalling takes some getting used to, it can be quickly mastered. However, those who prefer direct trail feedback might find the Sidekick hub a disadvantage.
Tops
- Quiet bike
- Less pedal kickback
- The bike feels more planted and gives a greater sense of security
Flops
- Quiet bike :)
- Less feedback from the trail
For more information, visit E*thirteen.com
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Words: Robin Ulbrich Photos: Peter Walker
