We set out to build a quiet hub. It evolved into something else entirely.
A hub makes most of its noise when you aren't pedaling. The buzz is the pawls dragging over the ratchet teeth, and it's also where the coasting drag comes from. So in 2017 the brief was one line: make a hub that's silent, with low drag.
We didn't assume we had to invent it. We investigated the systems already on the market first, and by the end of that process we hadn't found anything we could license or build into our own design. So Greg Thrash, mechanical engineer, and George Dubois, director of engineering, started on our own system.
Where the anti-kickback came from
Once we knew we were building our own engagement system, we built in a deadband: a window at the start of a pedal stroke where the pawls haven't engaged the ratchet yet, and the hub does nothing.
We didn't know how big that window should be, so we made it adjustable and rode it both ways. Sixteen degrees at the maximum, which we suspected was too much for some bikes. That suspicion is why the adjuster existed.
Then we noticed what it was doing to the suspension. Run it wide open and pedal kickback disappears altogether.
So the hub's signature feature started life as a tuning knob on a quiet freehub. Nobody wrote "fix the suspension" on the 2017 brief. The suspension finding arrived on its own, from riding the adjuster in both directions.
It worked, on the right bike
The first phase ran a couple of years, and it ended with the concept a handful of pro racers ran as a prototype. By the middle of 2023 there was a well-developed version of the hub, and nowhere was it working better than the downhill circuit.
Then it went on a trail bike. Sometimes it engaged perfectly when you started pedaling. Sometimes it popped, or missed entirely. A downhill racer can live with a coin flip if the payoff is there. A trail bike customer cannot, and we knew it.
We had given wheels to the race teams before the engagement was solved, and those came back fast. As one of them put it: "Yeah, we like it, but you know, there's still this little thing that we're not sure about." They were right to send them back.
The pusher that flexed
George spent a long time trying to dial in that engagement. One fix was to make the pusher flexible, so that if the pawl wasn't completely seated in the ratchet, a little extra force would let the pusher flex and find home. It was a big improvement, but it didn't solve the whole problem.
Then the flexible piece started failing, because it wasn't robust enough for the job. We worked the material, and how the assembly was sandwiched together, until we had a version that lasted a long time. But that version no longer performed the way we wanted.
The flexing also had a second problem, and it was harder to pin down. You could feel it through the pedals. It caused no measurable harm. It was just a sensation a bike doesn't normally give you, and every rider who tried it noticed.
From the point of view of can you just give this to any person and have them ride it, it was an effect that was kind of a negative.
There was no data pointing at anything wrong. The problem was that it felt wrong, and the only test equipment for that is a person on a bike.
A printed part and a bushing
The first version of the design that actually worked was built by hand on Greg's bench. A 3D printed part mounted to a steel part, with a spring acting as the stop. The spring indexes against the teeth inside the ratchet, so the whole assembly can only come to rest in certain positions. Greg cut the first ones out himself, pulled the sprag clutch out of a hub shell, replaced it with a plain bushing, and put together a hub that worked.
Then he kept printing them and giving them to everyone in the company who had a hub to try them in.
The design fit inside the envelope we already had, and the cutaway freehub body we had already developed was compatible with it. All of a sudden, the years of work on bearings, seals, and feature locations had a place to land, and the hub came together. "There was some serendipity to that," Greg says. "I had a concept, and there was enough real estate available that I could make something that fit in the hub."
Prototypes, benches, and test rigs from seven years of Sidekick development.
Tuning the deadband, and drivetrain vibration
The adjuster is still there. You can set the deadband for a bike, or even for a single ride. Many people find a setting that suits where they ride and never touch it again.
Pedal kickback gets all the attention because it's the obvious one, but the hub also cuts down on drivetrain vibration. We've done comparative testing against high pivot bikes, which should have the same net effect on kickback, and the riding sensation is quite a bit different.
Two years of small decisions
Once the architecture was set, with the bearings here, the ratchet there, and the pusher there, the big decisions didn't change again for a long time. Hundreds of small ones followed over the last two years. Pawl geometry against the ratchet. The pusher's interface with the pawl. Bearing configurations to take the end play out. Fit tolerances. Manufacturing studies on what we could actually hold in production.
Greg's final idea was to time the pusher to the ratchet ring, so that engagement happens at one precise point instead of wherever the parts happen to meet. That one took off, and it satisfied everything we still wanted from the system.
The last fine tuning came out of the race pits. Sebastian, in our German office, and our product manager spent the final year working directly with the teams. One part sits in a bearing, and being off by 0.01 millimeter was enough to stop the hub working. Race team wear found it fast, which meant parts swapping in the pits and a lot of late nights.
What fifteen years of hubs bought us
We've been building hubs for about fifteen years, and the Sidekick inherits the parts of that work that have already proven themselves: ratchet ring material, ratchet ring geometry, pawl material, and the pawl manufacturing process. Those parts are about as close to indestructible as we know how to make them.
Where the space allowed, we doubled up on bearings, used the highest quality bearings we can get, and made sure the clearances are correct.
What it survived
Machine testing run to the ultimate and fatigue limits of every part in it. Wheels out in the field for a year and a half to two years with no issues. Race teams still on their original bearings, cleaning them out and adding grease between races, on a downhill program where the bikes get pressure washed between runs.
At the end of seven years, Greg's summary was shorter than any of ours could be: "That's kind of the invention in a nutshell."
What happened after it shipped
The hub that came out of all this reached the market in 2024. The awards followed.
Pinkbike named it Innovation of the Year for 2024, over a shortlist that included Schwalbe's radial tire casing, DJI's Avinox motor, and a tuned mass damper. The following January it took a Design & Innovation Award in components, an award whose jury tests products on the trail before scoring them.
Both juries also wrote down their reservations. Pinkbike's was weight: at 408g, the hub was heavier than the options next to it. The DI.A jury's was the deadband itself, which "can result in a slight 'ghost pedalling', which requires some getting used to."
Both notes are fair, and both are what Sidekick 2.0 went to work on.
Sidekick 2.0
Sidekick is now in its second iteration. The decoupling mechanism is the one this post has been describing. What changed is everything around it: magnets replaced the wire pawl springs (magnets do not fatigue), the deadband range moved to 9, 13, and 18 degrees, coasting drag dropped a further 30%, and the hub lost up to 38% of its weight, down to 275g in the Pro SP. The price of entry for a rear hub dropped to €249.95, about half the original's launch price.
Where the first version was one hub, 2.0 is four: Sidekick, Pro, Pro SP, and the GR, built for gravity and E-MTB, with its own 12, 15, and 18 degree deadband range. Every one is fully rebuildable and tool-free to maintain, rated for Class 1 E-MTB, and covered for ten years under Infinite Ride.
The full range is on the Sidekick hubs page.
