In-depth Wheel Tech Review: MTB Hub Engagement — Loud or Quiet?

32 min readJan 12, 2021

“To be a Swarming Bee or a Silent Surfer? That, is the Question.”

By Jake Brennand

Wheels seem to ignite passions like few other topics in cycling, an already too-passionate hobby for many riders. Maybe it’s because so many people have had poor experiences, for example with carbon rims breaking or wobbly truing sessions. But maybe it’s also because, as we state on the website for my Toronto company, Hogtown Spokes Elite MTB, wheelbuilding is the de facto “special ops” of bike mechanics. As a result (though I hope we stand clear of this general description), the egos in dedicated wheelbuilding tend to be a little larger than in the already inflated ego real estate of the bike-service industry. In the US military, the Navy SEALs are known for being brash and a bit cocky. By contrast, we hope that we’re more like the Army’s Green Berets or Delta Force, the so-called “quiet professionals.” The bike Bros come out vocally and rampaging when it comes to wheels (or suspensions), and they have their go-to, choice brands. As someone (maybe it was Russell Brand?) once said, there are drugs and there are “angry drugs.” There are no angry wheel or hub companies; every firm mentioned in this review sells serious products and runs a proper business focused on their customers. But there are angry wheel riders—or those individuals on two wheels, with hubs at their core, who seem partial to certain companies and are part of the talking-head industry subset known in our workshop, jokingly, as the “Bike Brethren.” These are the unreconstructed Aldous Snows of the MTB world. Some of these types in turn belong to a different MTB subset dubbed the “Continental Priory of Angry Bike Mechanics.” (This is why we give away decals with our new wheelset purchases with a unicorn and the proud notation FRIENDLY MECHANICS WORK HERE.) If it’s fair game to tease a Fliers or Senators fan or a fan of the hated “Evil Empire,” the New York Yankees, then a bit of the same should not be off limits in offroad cycling. Entire companies have built strong businesses selling to Pinkbike’s anonymous “dentist” cadre — the rumoured guys (and it’s always seemingly dudes) who ride in the comments section armed with irreverent e-pen and supposedly massive disposable incomes for Superbikes in only the best carbon layups. The fresh, oligarchical caviar of carbon. Dare I say it, only the reserve batch. Santa Cruz, Pivot Cycles, Specialized, and others admirably take these knocks in stride and keep on selling, innovating, and turning a profit, as well they should. These are genuinely great bike brands selling great bikes to a range of different folks.

**“Get Him to the Greek,” Universal Pictures (2010). To my enormous relief, I have never seen anyone partake of a Jeffrey while riding. Let’s hope that continues to be the case.**

Getting to the point, the key debate now in mountain bike hubs is between a loud design, or a design relying on a traditional “clicking” pawl operation, and quieter or even virtually silent hubs, an effect created in cheap hubs either by slower engagement with fewer pawls and drive-ring teeth or, in the case of expensive products, with sophisticated high-engagement activation such as the sprag-clutch design adapted from other industrial applications into cycling. The loud category — still overwhelmingly more popular, due to their greater availability in the marketplace and cool “swarming bees” sound for many people — is most associated with UK-based Hope Tech, Chris King of Portland, or North Carolina located Industry Nine (“i9” for short). The quiet camp, alternatively, is most associated with the Onyx Racing company, based out of Minnesota (like Park Tool) and founded by a guy with an expert machining background who acted as his kid’s mechanic for BMX comps. In my personal research, industry actor, and online commenting experience, Onyx tends to be one of the Bro passion brands, for whatever reason. Onyx certainly didn’t choose to be this as far as I know, and Onyx escapes any pejorative associations if this description is indeed accurate for others’ lived experiences as well. It is what it is. The loud companies also have plenty of goofy followers — you can trust me on that. Finally, companies such as DT Swiss, a long-time hub stalwart in terms of reliability and smoothness, or Shimano, are somewhere in the middle sound and engagement wise, just as DT and Shimano graphics are fairly subdued and middle of the pack. DT is a stereotypically Swiss corporation: happy to keep a lower profile based on reliability and quality over visual splash. Shimano, equally, is a typically Japanese company, overwhelmingly for the many betters in that notation and also for worse if you’re after constant social-media outreach, a personal customer feel, and visual or personalization pizazz.

This deep-dive Tech Review will explore the entire spectrum of hub sounds and technology in detail, its frequent fans and adherents, and will hopefully allow readers and Hogtown clients alike to come to their own conclusions about what is best for them in terms of hubs on high-end wheelsets.

Full disclosure: I ride a Hope Pro4 135 hub on my Commencal META HT.

What would these Brethren ride? One thing’s for sure: former Chief Justice Warren E. Burger, not to mention Associate Justice Harry A. Blackmun — each a proud natural or working son of Minnesota — would probably have chosen Minnesota-based Onyx if mountain biking was a thing at the time. Onyx makes passionately popular hubs of very high quality. Just expect to see some real chatter in the forums if you join the Silent Army.

Loud County: Hope, i9, Chris King, and Others

Bike freehubs (rear hubs) work using a ratchet design. All conventional, noisy (click-making) freehubs share some version of this concept. A hub is made up of a shell — the large, often anodized aluminum body that you can see externally — and a number of integrated key parts, including the axle, freehub body, bearings, drive ring, pawls, spacers, and other miscellany such as plastic or rubber weather seals. The best modern freehubs, as with the popular Pro4 from Barnoldswick, England, company Hope Tech, or the Hydra hub from Industry Nine, can be mostly disassembled without the use of dedicated tools. Simply pull off the driveside end cap, remove the cassette (or don’t) and then pull outward on the freehub body itself and off it will come (with large modern cassette still attached if it wasn’t removed first —generally not recommended). Inside the freehub body riders will find an integrated cartridge bearing (usually one of four total in top-quality rear hubs) along with the surrounding pawls, which look like little steel wedge-hooks. Left attached to the hub-shell body will be the protruding axle, cased with its own cartridge bearing, and the drive-ring mechanism, located between the bearing and the internal walls of the hub shell. (The drive ring is now often screwed onto the inside of the shell.) The hub works when put back together simply by, when rotated clockwise under pedaling forces, engaging the pawls of the removable freehub body with the drive ring that sits over the axle and bearing inside the surrounding hub shell. The design is considered to be ratcheting because, when moving clockwise these two male and female surfaces mate, locking together and driving the bearings in crisp revolutions around the polished axle — causing forward motion of the bike. When moving counter-clockwise or simply left stationary (aka when “coasting”), the pawls will not grab the drive ring and instead “slip and glide” in a reverse circle over the drive ring’s teeth, thanks to their being spring-based in the freehub body and their lubrication with one or substance. The mechanics of a rear hub are thus elegantly simple and time-tested.

From their Instagram: Industry Nine Hydra freehub body. Notice the 6 leaf-spring-based pawls with ABEC bearing at their core. On the right of the body is the drive ring (taken out of the hub shell), in all its North Carolina glory with 115 precise, tiny teeth. The uber-machined pawls lock into these tiny teeth, in phased progression, under propulsion; they then slip back over these in “coasting” mode — producing i9’s “swarming bees” noise that lights up Southern forests from Raleigh to greater Savannah. Y’all will hear it indeed.

It’s this counter-clockwise slip-gliding of the steel pawls against the drive-ring teeth at speed that produces a conventional hub’s loud clicking noise, which only escalates with speed and cadence. In hubs with “high engagement,” so-called, which may fairly, if a little arbitrarily, be described in this review as hubs with enough pawls and teeth to require less than 8.5 or so degrees of clockwise hub rotation caused by a rider before the teeth-pawl locking action and bike propulsion kicks in, this noise can be quite loud. Hope’s sound, maybe the loudest in cycling right now, comes from 4 large steel pawls cadencing backward against 44 largely and precisely defined drive teeth. The number of pawls, number of drive-ring teeth, and number of degrees of engagement resulting are often associated with a shorthand description of general hub quality by riders and technicians alike. More is more with pawls and teeth, it goes; less is more with degrees of engagement.

The “number of points of engagement” (POA) of a hub capable of engaging the collective pawls in phased-progression designs, like i9's, may be calculated by MULTIPLYING the: {number of pawls} x {number of drive-ring teeth}. So, in the case of the leading conventional phased hub, i9’s Hydra, now several full seasons into the MTB fray, the freehubs have “690 points of engagement” because they feature: {6 pawls engaging for all intents separately and progressively, in phases} x {115 drive-ring teeth} = 690 POA. Hope, by contrast, has: {44} possible points of engagement, because, while each Pro4 hub has 4 defined pawls, they activate simultaneously for the purposes of starting bike motion. Hope has 44 teeth in its drive ring, so that’s the simple Pro4 POA number. From this point, the “number of degrees between engagement points” is calculated by DIVIDING: {360 or the number of degrees in a circle} / {POA}. Thus, the Hydra engages every 0.52 degrees or virtually instantly, which is remarkable. Hope Pro4 hubs engage every 8.18 degrees according to the math. Cheap rear hubs will have fewer pawls and/or drive-ring teeth, producing less impressive numbers. For example, a generic OEM hub in MTB might have 18 teeth and just 2 pawls (plus cheap bearings), which would result in only 20 degrees of engagement but with the added system and efficiency stressors of only two pawls able to grab and take the wear and the crummy bearings. Note that road-focused hubs, even of quality, have higher degrees of engagement to save weight (via fewer pawls) and because of the typical manner of road cycling. On tarmac, riders build up speed more progressively and with tighter cassette progressions. More rarely in road cycling is a rider looking to “flat gas it” after a hard technical exit. Plus, there’s no rocks and roots (beyond the cobblestones of the Tour). High POA therefore isn’t essential. That being said, some road riders do need higher engagement — and many sprinters will fit this description. A lot of credit is due Cycling Tips’ Matt Wikstrom, for his excellent exploration of POA in MTB and road hubs.

What do these number differences mean for actually riding a bike? With higher engagement, the bike much more directly responds to what you do with your legs. Push on the pedals and the bike “gets up and goes” a lot quicker. It’s that simple. This is especially important on technical climbing sections, where even Olympians can’t simply rely on their legs to move a stalled or stalling bike. Conquering rocks, roots, and uphill switchbacks requires much more engagement from a bike hub — at least to a point (to be explored later in this article, in the context of discussing “crank backlash”). More engagement is justifiably a big marker of MTB hub quality. Hydra hubs deserve to swagger.

But, unsurprisingly to the curious reader, it’s never quite that simple. Hubs aren’t only rated for quality according to how much “go” they create. Hubs are also heavily judged by their durability, a complex and multifarious topic. As one can imagine, the coasting feature of a conventional hub eventually wears out the pawls and the drive ring. But because these are steel parts and benefit from lubrication inside the freehub body, whether by using a specialty grease (medium-sounding hubs or loud hubs deliberately quieted) or engineered oil such as that made by Dumonde Tech for the Hydras (in the case of loud high-performance hubs left or encouraged to be inveterate trail screamers), this process takes seasons to occur, usually several at least in normal conditions. The greater cause of pawl and drive-ring wear is, expectedly, the forward motion that actually produces freehub engagement and bike propulsion. All of the torque involved in the latter — especially now in the context of Boost (148 mm) and SuperBoost (157 mm) rear hubs and modern high-volume cassettes strapped to 29" rear wheels — takes its toll. Thus, for the engineers, the real battle in a hub’s design begins after the sexier engagement and degrees issues are sorted and focuses on engineering greater durability. It’s in this area that Hope and Chris King have made big production efforts to stand out, but also where i9 ultimately takes the prize — and by an arguably long margin — as the champion of the modern loud Superhub. I9 is, simply, a next-level rear hub.

As many hub reviewers and i9 themselves have explained, when a rider starts adding forward inputs, pedaling clockwise and taking the bike ahead on the trail, hub pawls will typically grab all at once. That’s the idea, anyway, and is true until you encounter harsh physics. MTB has physics, right? The physics of lateral and radial torque on a rear bike wheel mean that vibration and canting forces are always trying to pull the hub in umpteen non-uniform directions. The result is that not all of the pawls will actually stay engaged together at the same time. Most hubs tack with one or two tops when torque gets really janky out on the trail. It’s therefore not hard to imagine what this reality of dynamic physics means for wear and tear: pawls taking the load by themselves, even for split seconds, repeatedly, will wear out, as will drive rings and the bearings shouldering diagonal loads. Enter North Carolina’s sharpest cycling minds.

The braintrust at Industry Nine, a deeply likeable (they really stepped up, helping to make masks during the initial COVID-19 lockdowns) and slightly hipster company (as with Chris King, over on the West Coast) located in the very likeable and hipster North Carolina city of Asheville, decided to address the issue head-on by building in a ton of drive-ring teeth (115) and by using a progressive 6-pawl design. The idea is that by having so many sensitive teeth and pawls, carefully machined to work together in phased-in unison driven by the amount of power laid down by the rider, the hub will actually benefit from the torqueing forces of hard riding. The hub is expressly designed to activate with a single pawl and then at warp speed almost domino-effect into employment the remaining pawls. The effective result: six different clicking grabs in an activation. This is why with i9, to calculate degrees between points one doesn’t just divide 360 by 115 (number of teeth in the Hydra drive ring), as with almost everyone else. Instead, you multiply 115 x 6 first = 690 POA. The more twisting and torqueing, the more likely that 6 pawls will all separately find one of the 115 drive-ring teeth in the packed Hydra shell and stay that way. In other words, i9’s design team took physics and marshalled them to suit their purposes: a truly classic purposive, dynamic application of industrial design and engineering. Smart work by i9, the result, reportedly, of more than two years of R & D.

Industry Nine claims, backed up by numerous MTB testers and racers and my own observations servicing these hubs in my workshop, that less wear and tear will result over time versus other high-performers. One of my clients is a really enthusiastic rider close to 6'3" and over 220 pounds, estimating. He rides like a bull, leveraging the crap out of his big enduro bike. He’s a great guy who loves to shred and can literally break quality butted spokes. When I serviced his rear wheel (originally built elsewhere) in summer 2020, the internals looked flawless. The hub was in its first season — but I have seen first-year rear hubs that look a lot worse. This client had also sometimes used Dumonde Tech hub oil, wanting a loud “killer bees” sound from his i9 Hydra (he now primarily uses Dumonde’s low-viscosity grease, which is awesome and results in a Hydra nearly as loud). But oil also comes with thinner lubrication for the internals than that offered by grease, which would logically seem to increase potential wear. Not so in reality, a testament to the genius of the Hydra’s durable engineering. Of course, making a freehub with this many tiny teeth and precision pawls isn’t cheap, which is why a Hydra rear hub runs the better part of $600 CDN from many retailers. For that price, we consider a customer to be getting the finest loud hub that money can buy, period. As they should. And it will last.

Hope and Chris King attempt to address durability largely with the tried-and-true — if less imaginative — methods of consistency in manufacturing and sealing. Hope Tech set up shop in 1989 in a Barnoldswick factory, founded by two wonky former aerospace guys who had worked for Rolls-Royce. Chris King brought obsessive manufacturing and large, aggressive hub shells (useful for riding stiffness and wheelbuilding integrity) to the US cycling scene. Chris himself is an interesting guy; the only appropriate analogy is with the golf industry’s master putter personality, Scotty Cameron. Like i9 or Chris King, Hope is a great company with a proud and loyal operations staff committed to UK quality. Hope achieves minimal wear and tear using tons of precision CNC-piloted manufacturing steps, expert factory assembly by a skilled staff, tight tolerances, and arguably the industry’s best sealing. Hope makes hubs for dreary UK weather because they need to be sealed for dreary English and Scottish and Belfast and Welsh weather. But as a result, all Hope users, the world over, end up benefitting (myself included). And they’re verifiably made for UK conditions, as anyone who has ever serviced a Pro4 knows from the force needed to click the main driveside — iconic green — seal back into place when re-attaching the freehub body to the axle and hub shell. When you keep out the muck and grime and especially the pesky sand or road salt (it’s Canada, after all), a hub’s pawls, drive ring, bearings, and other internals will all last a long time even without Hydra levels of engagement, design, and crazy-miniscule machining. Hope probably surpasses the Hydra (as maybe does Chris King) for sealing security.

But what about the Dragging with Clicks?

The main drawback to loud high-performance hubs is that the clicking noise isn’t just machismo and trail confidence; from a physics standpoint, it also means drag. The more pawl contact the more resistance a bike has in coasting mode. This is why the roadticians use fewer pawls. Hope’s road hub only has a couple inside of it. Drag is a significant factor, in theory, in applications like road racing (or downhill MTB) where riders are frequently forced to coast between sprinting or when careening down descents. So how do Hope, i9, King, Profile Racing, and others in the loud game address this arguable drawback? The strategy is effective, in my experience, and three-fold. First, they use pawls with minimal underlying spring tension, so that the pawls passively allow themselves to slip up and down over the drive-ring teeth in coasting mode without undue mechanical hesitancy. Typically this means, as Industry Nine has now done with the Hydra hub, which improved on their predecessor hub the Torch in this area, using a leaf-style spring with softer response for the pawls. (Torch, earlier, had used stiffer coil springs.) Careful grease selection and maintenance is another strategy. Thirdly, these companies spec high-quality cartridge bearings and use as many as possible. Four ABEC-5 or equivalent-quality bearings, spaced as widely as possible, plus the other strategies noted, will do much to keep even a very loud hub from dragging overly while in coasting mode. In my experience, bearings are massively important to actual hub performance on the trails. The Hydra spins A LOT. So does Hope, for that matter, or the iconic Christophers.

Onyx: The Silent Army

Before anything else, the quality and precision of Onyx Racing Products hubs needs to be acknowledged. Onyx makes premium mountain hubs and runs a highly respectable business by any objective measure. They genuinely care about their clientele and specialist wheelbuilders. They’re good people from a good state in Minnesota. That Onyx — in my informed personal experience — tends to attract a dogmatic following among The Brethren of the bike industry is hardly Onyx’s fault and is undoubtedly a handsome (and thus arguably smart) business for them. Onyx has plenty of really terrific and diverse riders using their products as well. Maybe mostly so. But for whatever reason, Onyx seems to attract the super-opinionated and bullish types, too. They do locally here for sure. Perhaps it’s the hubs’ exclusive and exotic pricing. Perhaps it’s their endless array of colours and fitment options for personal customization and swag. Onyx is the most personalize-ready hub company these days, even offering different-colour removable end caps (they call them widgets) to suit rider preferences. Perhaps it’s that being different — using a sprag clutch instead of pawls and a drive ring — attracts a “circling the wagons” mentality among the Onyx hubs’ contrarian ownership of riders.

One deeply mystical and more than slightly ideological explanation I continuously come across for their strident fanbase is the description, given to me in 2020 by a bullish user, of the hubs as joining rider and trail in some sort of transcendent serenity. This description follows the Onyx company line nearly verbatim. No, you’re not riding on Seabiscuit when you ride on Onyx. You aren’t one with hub-horse while serving some ennobled competitive purpose beyond yourself. They’re really great hubs, but still just bike hubs. But to their diehard audience, an Onyx advantage is that they supposedly let you “hear nothing but your tires on the trail.” Fair enough. These worshippers are probably as mystified by other riders’ odd attraction to the “swarming bees” noise of i9 or Hope or Chris King. Nevertheless, the Onyx description is a bit much for my taste. They state on their website, whimsically:

Listen carefully. Only the sound of the wind in your face separates you from the mountain. Enjoy the music of nature unfettered by the rancorous clicking of pawls. Onyx’s patented sprag clutch design removes the ratcheting noise of traditional hubs.

That it does, Charles Dickens. Except, what my Onyx priest in 2020 was never able to explain to me (and neither can Onyx officially) is why it would then be advantageous to hear every other OCD-activating element on one’s bike from the chain to bad derailleur shifts to creaking fork CSU or carbon handlebars and crackly, worn rims? As one otherwise pleased Onyx owner has put the matter on mtbr.com, “The worst downside is that the scraping sound of disc brakes dragging on 4-piston calipers is much more noticeable when I’m coasting.” A fundamental of sound and safe riding is looking ahead, downward on the trail — not looking at the immediate trail and listening for a silence-based religious conversion in your forested temple. You can perceive that I’m a little cynical about the Cult de Silence. Simon and Garfunkel were not, but I am. And even while truly respecting the impressive Onyx hub tech. I will say that I get the argument for bikepacking, made by bikepacking.com’s Skyler des Roches back in 2017 (for the Onyx Classic hubs).

The Sprag Clutch

No, Onyx hubs were not designed by Ed Sprague, the Toronto Blue Jays’ affable 1990s infielder. “Sprag clutch” refers to a design pioneered elsewhere in industry and used on moving vehicles such as cars and chopper rotary blades. In place of pawls and a drive ring, Onyx uses what looks like a couple of splined rollers in rows: the sprag-clutch method. These are designed to interlock on the drive-shaft assembly, instantaneously, upon and causing forward motion of the bicycle, and then they completely disengage when coasting, hence their virtual silence. Onyx, rightfully so, claims instantaneous hub engagement as an official spec, making the normal rear hub math wholly inapplicable to them. And their hubs are apparently extremely quiet in all riding conditions, as long as they’re working properly. (Admittedly, I have not personally ridden one; I have, however, kept up with my professional reading and learning duties in becoming highly conversant about them.) In some impressive videos published on YouTube, Onyx indeed makes for a unique-sounding ride without a buzzing back end, and one of the main premises for these videos put up by fans and industry champions is that the hubs “spin forever.” They do so because, to Onyx’s great strength (and also great, i9-like price heights) they spec their hubs with hybrid ceramic cartridge bearings. As most cyclists are aware, ceramic bearings are rounder, smoother, and better self-lubricating. They are, in essence, superior bearings in every way.

But…Ceramic just Because — or is it Necessary with a Sprag Design?

Ceramic bearings are a fantastic addition, and no doubt a large reason for their supply with Onyx products is that the company’s founder genuinely believes in a high-quality premium product range. His careful interest grew out of BMX, where, as others have pointed out in reviews, quick engagement and coasting momentum are critical. However, arguably Onyx hubs wouldn’t be marketable without hybrid ceramic bearings. This is because a rugged sprag-based design is inherently heavier than a conventional, pawled design. The sprags themselves are heavier and need sturdy encapsulation. A heavier overall hub thus needs making up somehow, and arguably the fancier stock bearings supply that making up. The original Onyx hubs that landed with a splash roughly four years ago and are still officially recommended for heavy-duty MTB applications, were a quarter-pound heavier than the high-end competition, routinely weighing in at around 470 grams for a rear hub. By comparison, DT Swiss 240 EXP rear hubs weigh much less than 300 grams. Hydra weighs 286 grams quoted Boost 148 mm with Eagle driver.

Those familiar with my broad mechanical thoughts will know that I ascribe to the legendary maxim that in the rational cycling industry you get just TWO of price, strength, or light weight. In other words, since we’re a company that builds rugged and value-aware mountain wheels, I don’t have a lot of time for overly weight-weinerson thinking (at least for non-racers in XC). Even so, unsprung mass, which wheels represent, certainly can affect ride quality and suspension performance, so 150-plus grams saved, when there’s 454 grams in a pound, is not insignificant. Onyx understands this. Therefore, a couple of seasons ago they updated their original hubs with a 2.0 design known as the Vesper and geared at XC-trail (more moderate) applications. It features a smaller sprag concept and really beautiful and intricate machining designed to save weight. As with Shimano’s new XTR 12-speed hubs, the Vespers have star-like flange machining designed to save these grams. This has gotten the weight of the Vespers into a much more respectable range. Onyx’s website quotes 408 grams for a Boost 148 Vesper in ISO brake mount with XDR driver. But, as another — again otherwise happy — Onyx user reports on mtbr.com:

I’ve not heard of anyone wearing out sprag bearings period, but slipping vespers seems to be too common. The double row clutch the classic uses is probably w[h]ere these hubs need to be. There were no reports of issues until [O]nyx started playing the gram game.

Obviously forum posts need to be taken with a grain of salt. But it does seem that even the good alleys of the good internet are more peppered with complaints about faulty Vespers, the Onyx 2.0 product, however few overall, than about any issues whatsoever with the i9 Hydra’s design.

Both companies get generally very positive customer-service reviews, and i9 legendarily so. One of i9’s chief wheelsmiths, Mr. Ricky “Shaq” Muehl, is famous for his Instagram account devoted almost solely to the hubs and System (complete i9) wheels that he expertly builds, resurrects, and saves for beloved i9 riders. Ricky is a bona fide champ-ion. His bike has actual tassels adorned to it. He also loves dogs.

The one, the only, The Ricky. Best hands in the mountainous South.

The Undiscussed Issue so far — Crank “Backlash”

What unites both the loud camp and the Onyx fanboys in terms of a possible drawback is a physics phenomenon affecting all hubs and known as “pedal backlash.” Essentially, without getting into too much of the hard-to-decipher physics, in certain riding conditions and situations hubs will actually make the cranks feel like they are pulling or “kicking” from the rider before the hub is able to truly pull itself and the wheel-bike forward. That is, the cranks and chain will want to move and drift some before being overcome by a rider’s legs and the freehub. More engagement minimizes the effect, which, as Matt Wikstrom of Cycling Tips explained in a lengthy 2018 piece, is itself more manifest in low gear ratios. In other words, it’s the worst on crappy low-engagement hubs coupled in MTB with big cassette sprockets (i.e., on tech climbs). It’s unlikely that this combo would manifest itself as a rider being sassily smacked in the shin by a stray crank or pedal in the 50-tooth Eagle cog (that, if anything, is an effect for DH bike kinematic-based kicks…minus the extended cassette). It also most likely won’t freeze your drivetrain, causing you to tumble from your steed. What it could do is delay an average or even highly skilled rider on a tough climb or while accelerating. I personally have never felt pedal kick/lash as a truly noticeable issue — and even before moving up to a high-engagement hub in the Hope Pro4 (8.18 degrees). But it’s something to be aware of, and on paper it means that the faster the hub engagement the better the MTB setup, if drag is also kept low. So Onyx would, therefore, show the greatest advantage, followed by i9 and so on and so forth down the POA/degrees bragging list.

Sprag designs are further said to negate lash by their minimal drag when coasting, because they supposedly cause less “auto-rotation” of the cranks (ever spin a cassetted freehub in the stand and the cranks seem to float along, too? this is auto-rotation, as well as possible contamination). I can only speculate here, but perhaps the Hydra’s smart and intentional marshalling of torqueing forces would play a bit nicer than most conventional high-engaging hub designs with respect to lash, since the Hydra is designed from the ground up to make ostensibly negative physical effects the friend of the hub in action. And they also use fantastic bearings, as noted, which I have experienced firsthand in my shop during service examinations. Good bearings are the enemy of drag. Just a rough extra thought there. I could be off base, of course, in giving the Hydra tech that much extended credit.

Ultimately, pedal lash is no reason to outright avoid clicking or minimally dragging hubs. But it is a factual minor drawback, to be aware of with any high-engagement hub design, probably even with Onyx — nothing is entirely drag-free, despite any manufacturer claims. Lastly, for those truly concerned about pedal backlash, this effect may be offset, as Cycling Tips has sketched, with a mathematical formula. Chainring and cassette size, and to a lesser extent crank length, are factors in the lashing effect. Hate the possibility of lash? Does it torture you at night like a NASA scientist sweating in his Coke-bottle rims? Spec a max 46-tooth rear sprocket, use a larger chainring (34t+), and then shorter cranks (165–170 mm), plus a ripping high-engagement hub.

**Credit: Cycling Tips. Matt Wikstrom’s pellucid analysis and explanation of hub-caused backlash.** **https://cyclingtips.com/2018/12/hub-tech-understanding-freehubs-and-points-of-engagement/**

Hub-based backlash also becomes a nice segue into the third camp in the high-performance hub game: the moderate-sounders.

Alternative Designs: DT Swiss Star Ratchet, Shimano “SCYLENCE”

DT Swiss has for years laid claim to possibly the industry’s most reliable MTB hubs. Both the premium 240s and 350 series hubs feature DT’s iconic “Star Ratchet” mechanism, a technology now carried over into the newest 240 iteration, the 240 EXP range. (If they come out with a 350 EXP in 2021, the same tech upgrades will go there as well, at a heavier weight, slightly lower bearing/engagement spec, and with a cheaper price tag than the 240. [**Update: 350 EXPs indeed now exist for purchase.**]) The Star Ratchet, with characteristic Swiss simplicity and mastery, essentially is like a go-between from an i9 Hydra to an Onyx mechanically. It’s largely a conventional design, but it uses two intersplicing angled drive rings instead of pawls, aka the Stars, ensuring — crucially for wear and tear — that all of the teeth on the freehub Star driver will snag the receiving teeth on the Star ring inside the hub-shell body at the same time. This means, obviously, when combined with DT’s famously tight tolerances and proper maintenance by the rider, very durable internals. DT hubs last. The downside is that, partly to make this system possible, DTs come with a 36-tooth drive ring as standard (and just 18 typically in the 350 series) and a maximum 54-tooth Star Ratchet as an aftermarket upgrade. This comparably much lower number versus the Hydra and, effectively, versus the Onyx’s instant engagement, often gets derided by armchair quarterbacks on the more uppity MTB sites. Essentially, DT’s main response, which is likely genuine — the Swiss tend to be pretty no-nonsense with their tech — is that they believe 36 teeth is the best standard high-performance hub compromise factoring in crank kick, wear and tear, and presumably also the machining costs to produce. With a 36-tooth Star, the mating surfaces are larger for less abrasion through more surface-area contact, and it’s presumably significantly cheaper to machine a 36-tooth Star ring than a 115-tooth intricate Hydra drive ring. Hydras are so difficult to make, in fact, that i9 can only produce 60 in a 24-hour machine period at its Asheville base. Hydras are the legit Mercedes-Maybachs of MTB internals.

The newest DT 240 EXP hubs are all about taking durability even further, with wider bearing placement, fewer hub parts, less weight, and even better Star Ratchet wear as the top company claims. DT says that the bearing on the driveside hub shell going 7 mm further outboard increases potential wheel stiffness by some 15%. That’s a lot (and yet another reason to shirk carbon jackhammer rims). Wider bearings resist diagonal axial loads better, keeping the bearings rounder for longer. DT hubs are almost as well sealed as Hope Pro4s, in my wrenching experience. In terms of sound, while DTs certainly aren’t quiet, the sound is a much more businesslike “mellow bee” or perhaps a refined “Swiss bee” than the “swarming bees” of the Hope, King, i9, et al.

Picture: From DT’s website. Note the unique look of the Star Ratchet mechanism. The new EXP hubs, DT says, are even more durable, featuring wider bearing placement, among other things. Tried-and-true with the respected Swiss hub masters. Comes with a simple look — albeit with lots of red.

Another company in the middle is Shimano, with their new 12-speed hubs. Largely at Shimano’s own doing, a lot of confusion has surrounded these products. The entire new 12-speed line was delayed due to production issues reportedly caused, in part, by a factory fire. A lot of MTB press had initially went toward Shimano’s debuting a new silent hub design with the halting marketing name of “SCYLENCE.” It seemed that Shimano was intent on aping Onyx in its own way. However, just before the delay on 12-speed drivetrains writ large was about to clear, Shimano announced to the cycling world that SCYLENCE was going to be abandoned from the new lineup of 12S products. Hubs would be tweaked accordingly. Informed commentary online has suggested that, mechanically, this meant Shimano would be inserting a spacer into their new hubs (it’s certainly there — see the ivory-looking plastic thing in the photo below), designed to prevent male-female pawl total disengagement that could produce “SCYLENCE.” I can confirm from personal experience building up Shimano 12-speed hubs that the hubs are manifestly NOT silent at all. They engage a little slower than, say, King, but are faster engaging than past Shimano hub iterations (they’re quoted at 7 degrees maximum); spin very smoothly (Shimano is a stalwart of the older cup-and-cone, versus cartridge bearing, spinner system); and they offer great value. Being stock with the new 12-speed Microspline freehub, fitting a 10-tooth lowest Shimano cog, is the hubs’ biggest selling point for most riders. (With the other brands mentioned in this piece, Microspline 12S is now a selection option or aftermarket upgrade for rear hubs.) My experience so far is that the Shimano design looks and sounds closer to DT’s 240 than to the Hope Pro4 or Hydra, is fairly complicated internally, and while durable to date needs more expertise (such as that provided at my studio) to service. Shimano mandates special tools — we now own a $60 seal press for the task — and dedicated greases that are hard to find and stock. Note the anti-lubrication warning below.

From one of our custom wheelsets. Internals of a new Shimano XT 12-speed hub. Very un-”SCYLENT” after all.

Hopefully “SCYLENCE” will disappear entirely from any marketing. It serves no one to keep the weird misnomer around. Only Shimano can effect this communications change, and it needs to do so even more forcefully. Shimano, and perhaps this reflects a geo-cultural disconnect in their operations model, tends to delegate communications announcements of great import to regional reps, who then make the consumer-level honest case to riders, as when Shimano Australia marketing rep Toby Shingleton plaintively stated, “It’s frustrating that we advertised something we’re not able to bring to market,” as reported in a February 2019 Cycling Tips online article. What is really needed are statements such as his or those helpfully made by North American rep Nick Murdick — but superseded and guided by a systematic leadership communique and mea culpa from Shimano’s Tokyo headquarters. Transparency plays better in the Western marketplace. Shimano is an honest company with great items to offer riders and retailers; no one would hold a grudge for them simply fessing up even more comprehensively. Stuff happens in engineering and design. After all, SCYLENCE was apparently cancelled, according to Dave Rome at Cycling Tips, because Shimano has the spine to only release items that are fully up to its high consumer performance standards. Note that the non-series Shimano MT-510 hub, which comes with a Microspline-equipped body, simple all-black graphics, and a killer price point under $75 CDN, uses a more conventional pawled design as compared to the new SCYLENCE mech. Rome has reported that the latter is to be properly referred to as a “Helical spline.” Helical splines are also used by Chris King — possible inspiration for Shimano? The 510 hub, which I have built up repeatedly now, engages quickly and is as loud, or louder, than the so-called SCYLENCE tech featured on SLX through XTR-level 12-speed Shimano hubs. Its only real drawback is an original Onyx-like hefty weight, quoted by Shimano at 440 grams for a Boost 148 mm rear hub with Shimano’s proprietary centre-lock brake mounts (which are typically a bit lighter than ISO 6-bolt mounts). Shimano hubs now exclusively come with CL fixtures, so some users will need to factor that reality into their braking plans. Adapters may be used, albeit at a slight weight penalty.

Picture: Shimano.com. Since Shimano invented the Microspline tech, which allows for new 12S Shimano cassettes with a 10-tooth lowest cog to be fitted to theirs and others’ hubs— Shimano’s answer to SRAM Eagle XD drivers — all the new Shimano hubs come stock with Microspline freehubs on board. The new driver bodies grip a cassette much more securely, because of the increase in splines; the splines won’t end up self-marring over time as with the older HG models, where a cassette would repeatedly “bite in” under high torque.

In Summary — An Overall Framing:

The following companies make high-quality loud hubs, and loud hubs offer a number of riding advantages -

Industry Nine (Hydra; also the new “value” 1/1 hub, offering 90 POA)
Hope Tech (Pro4)
Chris King (any model)
Hadley
Factor Components
Race Face (Vault)
Profile Racing
White Industries
Kappius
Spank Hex Drive
New Canadian brand Tairin
Project 321 (if “loud pawls” option selected)

Loud hubs offer very-high engagement generally, translating into a lot of bike response on the trail, especially on technical areas and tough climbs
Loud hubs give off a cool (to some people’s perspective) “swarming bees” sound that is objectively a safety measure as well, since it lets other riders and trail users know a rider is coming/around them out on the trails
Loud hubs tend to be simple to service, use fairly standard performance greases or oils, and they may be partially or fully disassembled tool-free; Chris King is an exception, where special tools are a must for their service
All of the above companies offer a range of beautiful anodized colourways
Conventional hubs, particularly Hope and i9, are now really well sealed against trail ingress, prolonging bearings and the life of the hub internals

Drawbacks -

Engagement is never truly instantaneous, even with Hydra (0.52 degrees)
More wear and tear over time, in theory, because of the use of pawls
All of these brands are expensive, with only Hope offering a truly value option that still runs the better part of $450–500 CDN for a Pro4 hubset
Risk of pedal-backlash effect increases with drag caused during coasting

The following American company makes a high-quality “silent” hub, offering a number of riding advantages -

Onyx Racing Products out of Minnesota

Onyx hubs use a system of sprag pawls to offer silent riding with virtually instantaneous engagement — the industry’s fastest engagement, in fact
Onyx hubs come standard with swagged-out hybrid ceramic bearings
Onyx hubs come in a multitude of brilliant anodized colourways; Onyx may be personalized like no other hub brand currently available, and this includes the option to laser-etch their products
Onyx has one of the most user-friendly sites for wheelbuilding information
Onyx hubs allow for adjustable bearing preload

Drawbacks -

A design that only one company has actually mastered at this point in time, outside of True Precision Components (not reviewed here) or, possibly, Project 321 (also not reviewed here; if “quiet pawls” chosen)
Reports on even the better forums about hub slippage in the new Vespers
Onyx hubs are just as expensive as the louder competition — expect to spend $1000 CDN or more for a hubset
Potentially more difficult to service thanks to the sprag-based system (the sprags themselves, if damaged or faulty, though this is probably unlikely)
Sprag designs, even in the lighter 2.0 Onyx Vesper iteration, are heavier
You’re potentially buying a hub with a cult-like following among the MTB community’s more vocal and opinionated crowd; Onyx can be polarizing
No warning, via sound, for other trail users that a rider is coming. Since many of the MTB world’s vocal Brethren seem to vaunt Onyx products, and Bike Bros are perhaps less likely to use a bell on their trail bikes, this is a possible safety issue on the trail. Note that Onyx is NOT responsible
In place of not hearing your drivetrain’s engine, you may hear everything else right — and wrong — on your barreling mountain rig

The following companies make high-quality moderate-sounding hubs, offering a number of riding advantages -

DT Swiss (180 [ceramic-equipped flagship], 240s, 350, new 240 [and 350] EXP)
Shimano (12-speed, both SCYLENCE and otherwise, MT-510 namely)
Novatec (the highly underrated value face of Factor Components)

These hubs tend to offer a smart balance between wear, the risk of crank lash, and price to manufacture and sell to consumers
Reliable, proven designs — DT particularly so, with its Star Ratchet mech
Inoffensive sound: neither too loud nor dead-sounding out on the trails
Shimano and Novatec tend to be considerably more affordable hubs for common riders, while offering strong overall quality

Drawbacks -

Limited stock engagement numbers from the freehubs; DT Swiss offers a 54-tooth Star Ratchet (6.7 degrees between engagement points), but only as an extra-cost aftermarket upgrade; standard spec may not satisfy
Despite being reliable and durable, they are arguably more difficult hubs to service (Novatec excluded), requiring proprietary tools and greases as mandatory implements for the work to be performed correctly and safely
Muted graphics overall and a simple look — no multitude of anodizings

Our Final Verdict

Ultimately, we think, as many builders do, that factoring in all of the above considerations, both good and bad, Industry Nine’s Hydra is the best overall rear hub in MTB — albeit for those who can afford the steep price tag. Hydra is an unequivocally super-premium MTB hub, a Superhub, or a bucket-list hubset as my client on orange i9s (see pic below) put it to me. Hope Pro4 is the best-value reliable hub right now in the industry, and it uses the hardiest sealing available, literally and truly designed for the notorious UK muck and wet. DT Swiss is the hub for the value(ish)-conscious rider of conservative taste in bling and looks and seeking famous wear reliability and few stresses above all else. A classy hub choice, in short. While we do respect the very much elite features and performance reports on Onyx Racing premium silent hubs, given the number of possible drawbacks, their high price, and their loud conversational status in the tech community — which isn’t for everyone — we just aren’t convinced at this stage that they are worth the better part of $1000+ CDN for someone looking for premium hubs at the core of a custom wheelset. Not, anyway, when so many outstanding and more proven hub alternatives exist. It’s frankly nothing less than hyperbole to say, as Ryan Palmer did for BIKE Mag in 2016, that Onyx “makes other hubs seem unrefined in comparison.” All of these guys are refined now. For a grand+ or close to, i9, Chris King, or even Shimano XTR is a better bet, in our opinion. But that’s only our unsolicited builder’s perspective. For the true contrarian who wants a unique look, one could easily buy an Onyx front hub alone, mixing it with an i9 rear, going to town on the personalization ability of Onyx while benefitting from a front hub’s biggest draw: those silky bearings.

Nevertheless, each to her own. Ultimately, you can only go wrong in MTB now with truly dumb ideas like rim brakes on an enduro bike and tubeless tire pressures in the mid-teens. Avoid these minor travesties, and you will do alright no matter what you choose. Oh, AND USE BUTTED SPOKES!

-JB

“The Technician Who Cares Always Wins.”

**My client’s beloved (157 x 12 mm) i9 Hydra w XD Driver — the industry’s top MTB hub, in our view.**

#industrynine #hopetech #chriskingprecision #onyxracingproducts #DTSwiss #Shimano #FactorComponents #handcraftedinthebigsmoke #wheelsmith #hogtownspokes Jake Brennand