shimano scylence freehub ring drive ratchet design delivers silent drag free performance - prototype patent drawings

Thanks to rumor and hearsay from a Bikerumor fan and our own digging, we hear Shimano’s working on all-new hub designs. one that could offer quick engagement, more durable freehub bodies and nearly silent, drag-free coasting. And we found a few patents to back it all up.

The biggest update to their current designs is the switch to a ring drive ratchet system. DT Swiss has proven it with their Star Ratchet, but Shimano’s filing actually references Chris King’s RingDrive patent, but there’s a major difference in the way Shimano’s design moves the ratchet rings. And that difference is what eliminates the buzzing bee sound during coasting, creating quiet, fast hub that might just be the heart of XTR and Dura-Ace’s next generation hubs…

shimano scylence freehub ring drive ratchet design delivers silent drag free performance - prototype patent drawings

Shimano’s current hubs use a standard ratchet and pawl system, clicking small, spring-loaded teeth on the freehub body into a ratchet ring mounted on the hub shell. That’s an improvement from earlier designs used on lower- and mid-level hubs like STX in the 90’s, where the ratchets and pawls were all contained in a replaceable freehub body. Those were prone to contamination but not rebuildable, and with the smaller overall diameter required to fit it all inside the FH body, things just weren’t as good.

This new design, which we hear is called Scylence, replaces pawls with two ratcheted rings and a conically slotted section on the freehub body. Before we dive into how it works, it’s worth seeing how similar systems like DT and Chris King work:


DT’s Star Ratchet uses two toothed rings, one inside the hubshell and one inside the FH body. Each is spring loaded to push against each other, and the teeth are angled such that when you pedal, they mesh together and turn the wheel. When coasting, the teeth’s angles are like ramps and the teeth simply bounce over each as the springs jiggle in micro compressions behind them. Because the teeth are always touching, you get the clicking noise. And because there are so many teeth, particularly on Chris King’s hubs, that noise can be high pitched and high volume. DT offers three different tooth counts on their rings, which make more or less noise depending. Higher tooth counts mean quicker engagement, but also (generally) more noise and more potential drag.

shimano scylence freehub ring drive ratchet design delivers silent drag free performance - prototype patent drawings

Shimano’s patent flips the script, slightly. And it’s brilliant. Only one of the ratchet rings (31) is spring loaded, but the spring (34) is pulling it away from the second ratchet ring (32), back towards the hub shell (16).

Inside the sprung ratchet ring (31) are slanted grooves (54/58) that catch the grooves (42/44) on the FH body (30). When you pedal, the FH body (30) spins and those grooves pull the sprung ratchet ring (31) into the floating ratchet ring (32) and the teeth connect and drive the hub shell, thus rotating the wheel and propelling you forward.

shimano scylence freehub ring drive ratchet design delivers silent drag free performance - prototype patent drawings

When not pedaling, those same grooves push the sprung ratchet ring (31) away from the floating ratchet ring (32), and the spring (34) assists in retracting and holding it, keeping the teeth from making any contact. That eliminates drag…and noise.

The floating ratchet ring (32) glides freely over the angled grooves on the FH body, but has splines (64) that fit into slots (18d). When it’s driven by the sprung ratchet ring, the wheel is turned.

So, rather than push two toothed rings together, Shimano’s found a way of pulling one set of teeth into the other, then retracting it while coasting. Patent drawings are typically not 100% representative of the final product, but if those tooth counts are remotely close to real, expect very quick engagement.

shimano scylence freehub ring drive ratchet design delivers silent drag free performance - prototype patent drawings

From the looks of it, the sprung ratchet ring (31) won’t be moving much to contact the floating ring (32). All those moving parts are covered by a seal (36), and bearings are in their usual places – widely set with cup-and-cone adjustment on the outer balls. The arrows simply refer to the direction that the sprung ratchet ring moves when pedaling (D1, in order to contact the floating ring) and coasting (D2).

shimano replaceable freehub body splines concept patent drawings

On a separate patent filing application, Shimano’s exploring replaceable splines on the freehub body. At first glance, it may seem as though it’s a nod to keeping things fresh and not letting their cassettes dig too far into the splines. But, the patent reads differently, leading us to believe it’s done as a way to save weight without sacrificing (probably even improving) durability.


The patent mentions using a softer material (aluminum, which happens to be lighter) for the primary cylinder (aka: freehub body) and a harder material (steel) for the replaceable splines. Marrying two different materials isn’t a new idea – Woodman showed a different way of doing it at Eurobike, and American Classic actually has a patent on steel-faced splines. The idea on all of these methods is to get the weight of alloy with the hardness of steel.


It’s also probably cheaper than the alternative, titanium. The current Dura-Ace 9000-series rear hub uses a titanium freehub body, but that’s expensive. And, there’s no real weight savings over alloy, it’s just that it’s harder and less likely to have the cogs slice into it. That’s the explanation White Industries gave us when they switched all of their hubs to titanium. But for lower level products (Ultegra, 105, etc.), using a multi-piece design makes more economical sense.

From the drawings shown in the patent, they’re looking at a number of methods of attachment, from press-in to bolt-on.

As with all patent reviews, what’s shown here may or may not ever make it into production. We’ve heard things on the street to suggest one or both of these will make their way to products sooner rather than later. As one source put it, the new drive system could “make XT/Ultegra hubs laced to whatever rims a LBS staple again.” Shimano does not comment on products that have not been officially released, so can’t confirm any of it. Regardless, we’re excited to see such a unique design come out of a major house. Fingers crossed it’s on the road and trail soon.


  1. doug on

    In a world where it’s all about lighter, faster, etc. it seems like more effort should be made towards less drag, i think we’ve kicked the points of engagement horse to death. I’d miss the metallic click of my Hopes, but I’d gladly trade it for a ultra low or no drag hub.

  2. Andrew Spaulding on

    Yes! My old Shimano hub from the 90s on my steel beater bike is almost completely silent, whereas my new carbon bike creaks, squeals, and buzzes all over the place. I can’t wait for this to come out! Count me in.

  3. C on

    Good work Bike Rumor

    I am still waiting for you to talk about the SRAM 12sp mtb group which was leaked last week. Not much of a rumor site anymore 😉

  4. Steve on

    You say: “bearings are in their usual places – widely set with cup-and-cone adjustment on the outer balls”, However this is not how Shimano hubs are typically arranged. In the design above the outer most bearing (bearing on the left of the picture) is not the load bearing but rather to let the cassette freewheel, the bearing in the middle is also for the cassette, the bearing on the left would be the drive side load bearing which is greatly pushed in from a “normal” Shimano hub. This is more like a Campy other 3 pawl hubs.

  5. greg on

    I’m not seeing how the freehub’s ratchet ring and the spring are supposed to interact. Without something to catch it, the ratchet happily spins with the spinning freehub, not sliding sideways to engage the hub shell. If the spring does engage, then it likely clicks lightly on the freehub when coasting. To me, it seems like a mashup of DT’s star ratchet and American Classic’s cam plate.

    • Stathis on

      The spring doesn’t pool anything to anyplace. That’s just the op’s interpretation but it’s incorrect.

      The spring provides a small amount of drag to the inner ratchet ring (freehub engaged).

      When the freehub rotates faster than the hub body the slanted grooves “screw in” the ratchet (relative to the freehub) witch rides on the grooves due to that friction from the spring.

      When the hub body rotates faster the same drag of the spring makes the ratchet “screw out” riding on the same grooves and away from the outer ratchet ring.

      If no drag was present from that spring the ratchet would have no reason to screw in or out on the grooves, it would just turn with the freehub without any axial motion. The drag creates a rotational force on the ratchet witch is translated (in part) to axial motion due to the slant angle.

      One notices that possibly if the drag of the spring upon the ratchet is not correctly proportional to the axial motion drag of the ratchet ring on the grooves, the first will be insufficient to force the ratchet ring to ride the grooves towards the outer ring. I can therefore see the need for periodic maintenance on the freehub and inner ring to make sure the two ride freely without an steps or snags.

      Also I foresee that the drag of the spring in the inner ring will actually be considerable to ensure proper engagement.

      We’ll see.

    • John on

      @Dirk: “I’m guessing it won’t be available in anything Campy compatible. Bummer.” But 11-speed Shimano cassettes are 100% compatible with Campy 11-speed rear derailleurs. Unless you just have to run a 29 cog, you’d be good to go.

  6. Flatbiller on

    I actually consider the King buzz sound a feature, not a bug. I can’t stand Freds who put little lame bells on their mountain bikes; dude, you have a built-in horn called your voice. But if you have the King buzz (Hey, a Melvins reference!) going on, then your signal is very well heard.

    • Colin on

      90% of the time that I say “on your left” I get someone who turns over their left shoulder which cause them to drift left, getting in my way causing me to slam on the brakes or ride in the weeds to not hit them. If i ring a bell, they step to the right, don’t turn around and I say “thank you, have a great day” as I pass.

    • JBikes on

      A bell is emotionless. Sometimes when climbing, I may not sound the most polite even though I am trying to be. Yelling out “excuse me” or “on your left” to a pedestrian, can be taken in different ways as the force of my “yell” may be variable on how out of breath I am.
      With a bell, there is no emotion. No confusion on what is being requested.

      • i on

        I was going to say something similar, JBikes; I’m aware my voice can sound more aggressive than I mean, when I’m yelling loud enough to be heard a few yards down trail. A bell completely sidesteps that.

        Relying on obnoxious king hubs to get hikers to notice you? I’ve never seen that work – they never know what it is, just that something is making a lot of noise, so they stop in the middle of the trail and look around.

      • Tom k on

        I suffer from Ahole voice, no matter how nice I try to sound my voice just naturally pisses people off. Maybe cause Im old. I love my bell!

    • John Graham on

      Commuting on bike/run paths to and from work, it gets really old constantly shouting loud enough to be heard. Pedestrians also frequently react rudely when I am courteous enough to warn them that I am passing. As others have pointed out, the bell is dispassionate. My voice also thanks me.

  7. chadquest on

    The “teeth” on each of those plates should not effect how fast the engagement is, how fast those angled grooves pull the plates to each other is likely what will effect the engagement.

    In essence, this should work like a modifed bmx freecoaster hub, at least on principle, just applied differently.

  8. Veganpotter on

    I would never use Kings as an example for these hubs unless they actually have really high drag. King hubs definitely have spectacular engagement but they’re by no means efficient. Actually, the cheapest joytec hubs have less friction than a King hub.

    Friction wise, these should be compared to Zipp’s new hubs…at least once people have these Shimano hubs to see if its actually the case

    • J N H on

      I get the impression that people don’t put enough miles on Kings hubs to properly wear them in. My 2007 Isos glide beautifully, but it took a few thousand miles for them to get there.

  9. Dylan on

    Silence would be nice, I hate loud hubs. But the rest is a wash.
    Reduction in drag from freehub pawls is completely immaterial – don’t forget this drag reduction is when you’re coasting. Nobody ever go dropped because the ‘clickety click’ of their hub sucked too many watts out.

    Fast engagement is ‘nice’, but IMO it only makes a difference on the MTB (CX too I guess?). The relatively slow engagement of the existing DA hubs doesn’t bother me on the road bike (I have the 7800 C24CL wheelset).

    If I’m looking at those drawings right, then the ‘engagement’ will be determined by how far the ratchet ring has to slide in the ‘slanted grooves’ on the freehub body, as well as by the number of teeth on the ratchet itself. Depending on how far inboard the ratchet ring moves when not engaged and the slope of the grooves, this likely adds a few degrees of rotation at the freehub before the hub engages – it may or may not be ‘very fast’.
    It also looks like actively backpedaling might push the ratchet ring further inboard than it might retract by itself under spring tension, increasing the engagement angle. Given that the only time fast engagement really matters is on the MTB when ratcheting the pedals to clear an obstacle, this would seem to defeat the purpose.

  10. bearCol on

    Silent, low drag, fast engagement. As long as weight is reasonable I’ll be buying a rear hub when available. I’ve had my eyes on Onyx sprag clutch hubs which are silent, drag free, and true instant engagement, but getting over the weight is a tough one. This design should be a lot lighter than a sprag clutch. Not sure if this design can match sprag clutch engagement, but as long as it’s 6 degrees or better I’m in.

  11. anonymous on

    When the freehub moves forward relative to the hub body, it forces the toothed plates together. For the toothed plated to retract, the freehub twists backwards relative to the hub shell, letting the toothed plates separate.

    I’m actually more excited about the aluminum freehubs. Might see Shimano hubs come down in weight and possibly cost. Ultegra might get some weight reduction compared to steel, and Dura-Ace might see a cost reduction compared to titanium.

    Sadly I doubt it will end up in the entry level wheels, which is a shame, because Shimano hubs are relative boat anchors.

  12. Antipodean_eleven on

    Drag or no drag, on the trails or on roads/paths with others on them, loud hubs are, strangely enough, a safety mechanism – people hear you coming and if I want to give people a head’s up, without saying something of the ping of my wee bell (yes, all my bikes now have a Spurcycle bell), freewheeling always does a great job.

  13. Heffe on

    I love Chris King stuff but that sound from the rear hub is unbearable.So hats off to them if they can bring the good aspects without that horrible racket.

  14. Eric Hansen on

    I think saying this is going to boost XT/Ultegra sales might be a little myopic. Really, the majority of the cost increase from XT/Ultegra to XTR/DA is in that titanium FH body. Get rid of the fantastically expensive FH, and you’ve just got better bearings and from what I hear a different forging process. Should drop the price on XTR/DA stuff down by a lot. I *definitely* am going to get these for my MTB. Anyone want DTS 350s on Easton ARC 24s? New, never ridden. GTFO my bike.

    • bearCol on

      We have plenty of loud hubs to choose from, silent ones on the other hand are very rare. My i9 will be on ebay as soon as I buy this or an onyx racing hub. I love i9’s 3 degree engagement, but I don’t like the sound of angry bees in a jar constantly in my ear.

  15. greg on

    The freehub would slide the toothed plates together IF the plate on the freehub’s angled splines is being resisted by something (likely the spring, but how?)
    And ditto on @Steve’s observations on bearing placement and function….

  16. Kernel Flickitov on

    See no reason to support a company that undercuts the LBS by selling direct the Amazons of the world. Have a set of Onyx road DS hubs laced to Pacenti SL23’s for the last two years that have been excellent! By far my favorite wheel set in the last decade. Infinite engagement with a sprag clutch drive chamber and completely silent freewheeling. The rear hub weighs 100g more than anybody else, but it’s the center of the wheel, does not apply to rotational forces. Weight weenies can kiss my _ss! Arguably a quicker feeling wheel set than any King or DT that I have. They’re all pretty great but Onyx is something special.

    • Charles on

      “that sells to the Amazons of the world”. Wow, do you not buy anything “made in China” also? How about anything not made in the USA? But then again, many US companies drastically underpay and overwork their employees…Hmm, must be tough figuring out which “injustices” to be outraged by…

  17. theGrinder on

    I’m assuming the the spiral spring engages into the “square hole” – 16e and also the tang on the end of the spring must engage or mate with a shoulder inside a recess/groove in item 31. Such that item 31 rides “up” the slanted teeth of item 30 when pedaling, forcing the spring to “unwind” – this will make the spring diameter grow ever so slightly. Once you stop pedaling, the spring is always wanting to contract back to its “natural” size and thus dis-engages the mating teeth. Amazes me how they can manufacture all these bits to fit/slide in such a confined small area. To keep everything parallel/perpendicular with such tight tolerances. The actual movement of the ratcheting bits to engage is only millimeters. Pickup will be only a few degrees.

    I wonder what would happen if dirt and debris get past the seals in there – could the dirt “friction” turn your bike into a “single speed” if the ratchets cannot dis-engage? Just a thought and potentially not what you want to happen at an inopportune moment!!

    No doubt they have considered all this – still amazes me. The sizes and shapes of the items goes against known engineering issues of “coggling” or “crabbing”.

    • Dylan on

      No, Shimano are right on with this one. Loose balls are much easier to service and last much longer than cartridge bearings. It may be a little easier to get water and dirt into a loose bearing wheel, but it’s also easier to change the grease, and the bearings are less likely to go rusty even if you don’t because the water finds its own way back out.
      Remember how long old fashioned square taper BBs with loose bearings used to last? Until last year, I was running the same BB in my commuter/tourer that I bought it with in 1990. I last serviced it at something over 13000km…in 1996! Since then it has probably done about the same again (shorter commute, less touring and more bikes in the stable). I only changed it because it the rest of the drivetrain had worn out and I couldn’t get decent shifting chainrings for the original Shimano DX crankset anymore.

    • bbb on

      Totally agree and it’s the reason why I never even consider Shimano hubs for my builds. In theory cup and cone system is better, in real life it’s not. Shimano continues making it because… they can.
      Servicing cup and cone bearings is a messy business and you need to stay on the top of the maintainance in order to prevent the bearing races from pitting. The hubs are effectively consumables.
      With cartriges bearings you replace them only if the play or roughness is intolerable. If you’re lazy or don’t have time for maintenance you’re only going to damage the bearings not the hub. I have’t touched my rear Hope hub for over 30000 miles. It’s a bit rough but still rolling fine.

  18. Richeyhughes on

    I’ve seen some pics for 105 di2……….it would make sense for a new Dura Ace to come out this year now that all the previous tech has trickled down.

  19. Scott on

    If you add all of these comments together you basically get an American Classic hub. The RD205 rear hub is basically an average of: Lowest drag (other than Onyx), very light (other than hubs that cost 3x more) and overall best price for weight:drag ratio. It also already has the steel face inserts on the freehub body (nothing new about the Shimano hub). Also has all stainless bearings, no loose balls.

    I’m glad to see Shimano is doing something different, but its basically a DT hub with tweaks from other brands. One of the most significant things about this hub is the dome shape of pieces 31 and 32. DT uses rather flat pieces which can loose engagement due to the 15 mm axle that flexes under load. Likely Shimano is also using a 15 mm axle (not mentioned and VERY important) American Classic has a 17 mm axle which is significantly stiffer.

    You can already get Dura-Ace 9000 wheels for $700 which makes them pretty inexpensive for 1,390 gram wheels. However you have 16 spoke radial front and a 20 2 cross rear which is pretty flimsy. My AC Sprint 350 wheels have 28 radial and 32 3 cross rear and are $1,400 grams and roughly the same price… but are substantially stiffer and transfer power better and have lighter rims.

    This is a shameless American Classic plug. I just don’t think they get enough credit when compared in the marketplace to what else is available for the price.

      • Ellen on

        Hi Eric, sorry that is not true. If you have any questions about American Classic, feel free to call us any time. We are here to discuss this. The only time customers have bearing problems like this is when they use non-AC bearings they buy online that are not to tolerance. Best regards, Ellen AC 813-885-9040

      • Scott on

        That is a really dumb statement. I had over 12,000 miles on my Hurricane wheels before I replaced the bearings, sounds like you don’t know how to install bearings or adjust a hub?

    • Ellen on

      Thanks Scott! We don’t get enough credit. I rarely post on forums but I certainly don’t hide like our competitors do!

      Bill Shook designed the steel face cassette body seen in the patent above. I guess he’s going talk to the patent attorney today!

      Best, Ellen AC

  20. Alex Webster on

    There’s still going to be a bit of drag with this, because the spring is keyed to the hub shell, and will rotate against a ring which is keyed to the freehub. Interesting stuff nonetheless!

  21. chasejj on

    These are DT and Chris King killers. When Shimano comes out with these and maintains easily accessible high quality and replaceable bearings and races. Nothing else will make sense and they will no doubt become dirt cheap in comparison to other aftermarket sources. The CK/DT ring gear engagement is superior to any of the variations of ratchet/pall setups out there.
    Lower drag will separate them from CK/DT . No brainer. I hope CK is getting some royalties from this.

    • Kernel Flickitov on

      CK would only get royalties if Shimano was using the RingDrive™ system outright, which they are not! It’s Shimano’s own patented design. CK was only referenced in the patent filing as a similar system, but it DOES NOT function the same. You can only come to this conclusion if you actually read the article. Your sensational analysis of a hub release ‘killing’ off others is pointless, when DT released StarRatchet™ it din’t tank a bunch of aftermarket hub mfg’s, nor did King’s system.

      • chasejj on

        DT is not Shimano, BTW. If Shimano had offered a reliable drive system that I didn’t blow up regularly I would never have ventured into CK price category.

  22. bart on

    Shimano had to do something, frankly every does with the exception of CK and DT. The amount of cracked freehubs i have seen in the last couple of years has been astronomical. I can’t wait for this to come out. and as cool as a loud hubs can be, when i am out by myself in the mountains i want to be quiet. Count me in big time!

  23. shafty on

    @Kernel They don’t. Madison and others do. Distributors don’t often kill accounts because they’ve got no reason to. Especially when loss leaders like Jenson give them so much business. When I have a hard time selling Shimano stuff at retail, I’ll let you know. It’s certainly not a problem, and the customers who shop by price alone, you wouldn’t want in your shop anyways.

    The freehub looks to be a great design, but it’s wishful thinking, expecting it will be on bikes soon. Maybe we’ll see the 14sp group sooner…

    • Kernel Flickitov on

      Oh yes they do! I’ve worked for 2 online retailers and contract work for another 2 that all source directly from Shimano much cheaper than LBS cost. It’s also a well known fact as reported by BRAIN a few times in the last few years that surprisingly enough price isn’t the leading factor why people go to the big box online shops, it’s availability.

  24. chasejj on

    Kernel- I am a devoted CK user and build my own bikes and wheels as a hobby now (ex bike mech) . I can see the writing on the wall here. I like Shimano’s engineering on most things bike related and recognize a very well developed idea when I see it (M.E. as well). This will likely end my CK addiction if they prove reliable and serviceable. The remaining aftermarket hub users will likely be purchases by those enticed by shiny new finishes and colors rather than function and cost. JMHO.

    • Kernel Flickitov on

      This notion that you pose in which Shimano can and will rule the hub world while everybody else falls by the wayside is so out there I’m pretty much done taking anything you have to say seriously. You post actually make me chuckle a little bit, thank you for that!

  25. chasejj on

    Kernel- Way off topic , but you went there.
    I use online shops for 99% of purchases. As do others I know. Availability is great. But cost is very close on the hierarchy of decision drivers.
    Word of advise. Don’t open an online store in California(huge volume of buyers). States with much smaller populations are much better to avoid the sales tax applied to instate buyers. It is an issue in Cali where it is 8-9% on top of any discount deal you receive.

  26. fiddlestixbob on

    This looks interesting engagement-wise.

    I wonder though, about the replaceable splines. I mean even if you never replace them it allows you have have an aluminum body and steel splines, thus a weight that isnt too different from a full titanium freehub, yet cheaper and even more durable. Seems like a good idea to me.

    • Veganpotter on

      Honestly, having just one steel spline would be enough but maybe two to be safe… no reason to overdo it. I’ve seen American Classic hubs with a ton of use and only the slightest marrying without a change in shape

  27. Benedikt Skúlason on

    Great coverage! Different class bike journalism.
    But what am I missing here? I can’t see how the spring pulled ring (31) is pulled up against the wheel connected ring (32) for a proper connection there in between. Yes, I see the spiral grooves on 31 and the 42/44 grooves they interact with, but in order for these to pull 31 and 32 together there has to be something stopping them simply spinning together at the same speed (which obviously would result in zero pull action). 31 has to be prevented somehow from rotating with 32, until they have been pulled properly together (when they are under torque input and obviously Should spin together). Somebody?? Please. 🙂
    From where I am sitting, the only way I can see this working is if the spring is actually pushing them gently together (for a very light and silent touch), and then when you apply torque you rely on a very smooth slip (at an interaction angle slack enough) between the grooves on 31 and 42/44 which further assist the spring load in overcoming the “push away” force between 32&31 (which is dependent on the interaction angles between those two).

  28. RobertW on

    “That’s an improvement from earlier designs used on lower- and mid-level hubs like STX in the 90’s, where the ratchets and pawls were all contained in a replaceable freehub body.”

    DA 9000 hubs have the ratchet inside the replaceable freehub body.

  29. Benedikt Skúlason on

    After studying this one a fair bit, and then comparing to Ringdrive from Chris King, I ask: Are Shimano bringing anything new to the table that CK don’t already offer with their system? Or could this possibly just be a slightly shuffled CK design with the sole intention of getting past a CK patent?

    • Tom on

      A potential reduction in cost. Wider availability. Lack of expensive proprietary tools to maintain and loose ball bearings would all be reasons if Shimano gets it right. CK also knows a thing or two getting around patents. Just look at their headset design while the aheadset patent was effective. When it expired, CK introduced a very timely redesign with the GripLock. I am a very happy Chris King user (a road and a mtb hubset), but I am very excited what these end up being.

  30. theGrinder on

    @ Benedikt – you are right about the spring – it pushes rather than pulls.
    Applying torque (pedaling), causes item 31 to rotate CCW and push against end of spring + also causes item 31 to engage (translate/slide) into item 32 conical grooves – thus allowing the torque to drive the wheel.
    When coasting, item 31 disengages from item 32 by the spring force pushing radially inside item 31 in the CW direction – thus disconnecting the conical grooves.
    You sussed that out anyway but the article did mention “pulling” instead of “pushing” as you said.
    Interesting to see how it all works and a bit of mind bender til you get your head around what does what and when!

  31. Benedikt Skúlason on

    @theGrinder – Yes it’s a bit (quite a lot) mind bending. Which makes it all the more interesting! 🙂
    The way I see it (not saying I’m right though) is that applying torque simply aids the spring in further pushing 31 and 32 together. The only thing that the spring appears to be doing is making sure that there is some initial (minimal) interference between 31 and 32, to enable the conical grooves to initiate their action. Not enough spring action to make 31/32 transmit any significant torque, but enough to initiate the further locking function of the spiral grooves, which then properly interlocks 31/32. When coasting the interference surfaces between 31 and 32 push part 31 outwards (along the spiral grooves) up against the light spring, and thus releases. I would think that if the spring was supposed to directly spin part 31 CW/CCW it would need to have some ratchetting action with part 31, while 31 seems to be completely smooth against the spring.
    All this makes me want Chris King hub!

  32. theGrinder on

    not familiar with Chris King innards but as you say, it’s a variation on a theme between King and DT. What’s new? Just a refinement or evolution. Should mean low friction and silence.

  33. Rich on

    Finally! A technical explanation that echos what I’ve been saying sence the 11spd freehubs hit the market. “Along with the quicker engagement comes a price and that price is drag”
    Thanks Folks!
    Here’s hoping Shimano brings out a trickle down version of this freehub.

  34. zaharistoyanovZahari Stoyanov on

    The spring isn’t pulling the ring inwards. It’s pushing it and that’s what allows the FH to drive it outwards 🙂


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