Last weekend with the introduction of the new XTR M9100 12-speed groupset came the news that we are getting a new freehub body standard. DT Swiss sent out a quick note saying that most of their Star Ratchet hubs would be compatible with the new XTR, but and it looks to be a bit no more complicated than simply getting a new freehub body.

DT Swiss XTR-compatible Micro Spline freehub body

The new Micro Spline freehub body was ostensibly a Shimano design. But they partnered with DT Swiss during development to make sure that other premium wheelsets could be compatible with the new XTR mountain bike racing drivetrain. DT was chosen on the basis of manufacturing some of the most reliable, high-quality modular hubs on the market, and it certainly doesn’t hurt that they are a huge OEM MTB wheel manufacturer as well.

It was important to Shimano that once the new XTR group came to market, riders would have other wheel options beyond the new XTR hubs. The biggest part of that is really that Shimano elected to make hubs, but not complete XTR wheels. So DT Swiss wheelset compatibility brings a lot to the table for riders (and bike brand managers) not looking to custom build their own wheels.

A welcome surprise with the new Micro Spline freehub is that it was designed to fit 12 speeds and the small 10 tooth cog onto a body that was the same overall width. That in theory means the freehub can be easily swapped out, especially on any of DT Swiss’ higher-end, modular Star Ratchet hubs.

Even though DT is the only company currently authorized to produce Micro Spline freehubs, the reality seems to be that the development agreement between Shimano and DT Swiss appears appeared to prohibit DT from selling the new freehubs individually. In fact, it seems this won’t be a problem as originally suspected, thanks to an update from Shimano!

So while your current wheels with 240s hubs can swap tool free from Shimano 10/11 speed cassette bodies, to a SRAM XD driver body, even to the new Shimano Micro Spline cassette body if you could get one; DT can’t sell you the new freehub on its own

…only for now, we hope!

UPDATE from Shimano on June 4: Yes, it now appears that the freehubs will be available on their own in time for the Autumn XTR release!

Up Close with the new 12-speed XTR-ready Micro Spline freehub body

Like the SRAM XD driver body, the new Micro Spline body requires a bit of a special touch for DT Swiss, again fitting everything into the same space we’ve been using since before 10 speed mountain bike drivetrains and 12mm thru-axles.

The new Micro Spline gets 22 equally spaced sawtooth-profile angled splines for more positive engagement with the cassette. One of those splines is about double in width and with a larger space to easily align the cassette. Like the previous up to 11-speed design, full-length splines allow the use of either one-piece cassettes, individual cogs & spacers, or some combination therein like the new 10-51 M9100 cassettes.

The new freehub body design still uses a conventional cassette lockring – just scaled down to fit inside of a 10 tooth cog – which also pushes the outer bearing about 5mm back inside the body to allow for the lockring threads relative to XD, but similar to current Shimano 9/10/11.

That also means that the freehub itself is about 1mm longer than an XD driver, although spacing to the outside of the cluster of gears is effectively the same (remember that the SRAM cassettes cover the end of the driver with the smallest cog and the tool interface to tighten the cassette.)

The overall dimension from the hub shell interface to the outside of the axle end cap though, is the same. So no need for any modification of wheel, hub, spacing, or lacing to swap in a Micro Drive body. Like the XD driver, it does require a specific end cap to fit inside the new lockring, but DT will supply that with any wheel, hub, or (eventually) freehub body.

What does that mean for you?

Well, first of all M9100 XTR isn’t going to start rolling off the shelves anytime too soon. Shimano is promising “Fall 2018” availability on the new groupset. That means most of us will have at least until the end of the year to sort out our wheels if we are splurging on new XTR.

It looks like if you don’t want to build wheels with XTR hubs, this fall when you buy a new DT Swiss Star Ratchet rear hub or any of DT’s mid- to high-end wheelsets you will be able to simply select a Micro Drive body at the time of purchase.

For the time being though, it seems that IF you have an existing DT hub or wheel, you WILL not BE ABLE TO buy the new freehub body separately. The workaround may be to purchase the cheapest hub that shares the same size freehub body (say a 350?), get it with a Micro Drive, and swap out onto your fancy custom race wheels?

DT Swiss does look to be the only company besides Shimano itself who will be allowed to produce an XTR M9100 compatible wheel at the time of XTR availability. Much like the previous standard Shimano splined interface though, we can only imagine they will open up the design to other hub producers as well.

Talking with Shimano, they are always cagey, never confirming any future new product development. But much like they more-or-less admitted that a Di2 version of the new XTR groupset could be expected in the future, they also said they are fully behind the new 1×12 drivetrain setup (and indirectly the Micro Spline.) Essentially that was a confirmation to the question asked, “should we expect to see 1×12 trickle down to the likes of XT and beyond?”

So, it looks like Micro Spline is here to stay (or at least once it finally arrives for real this autumn.) And DT Swiss’ race support is already prepared. As select pros start racing on the groupset already – like Jolanda Neff on her prototype Kross that had DT hubs and Mathieu van der Poel on his prototype Canyon which had Shimano hubs – DT is ready to support the rider with Micro Spline freehub bodies as needed.

The rest of us will have to wait.


  1. Reason for the sawtooth profile? The only thing I can think of is that Shimano has decided they need to counter the natural outward force a spline experts on a mating ring (cog) under torque transmission (and rear hubs actually see a lot of torque given how thin and light bike equipment is)

    • It’s called price discrimination. If the freehub by itself was just readily available to everyone then they’d be missing out on an opportunity to squeeze a few extra bucks out of the gotta-have-its out there who will gladly shell out for a whole wheelset to accompany their brand new XTR right this moment. Classic move; pretty much the driving force behind trickle-down.

      • And they’ll probably open it up to allow DT to sell freehubs alone once they feel they have extracted as many sales as they can from this group and just before this prohibition starts to cut into overall sales of the group.

        Basic business moves – they are trying to maximize their revenue.

  2. I just can’t figure out the business case for not making the driver body available to the aftermarket. They could ask for exorbitant licensing fees, and maybe DT doesn’t want to pay those, but to just say “no, not at all” doesn’t make sense. There must be more to this story that we don’t know yet…

  3. I’d like to know why the sawtooth profile? Just for the sake of a patent?
    From a technical standpoint I could see it reduce some of the outward radial stress on the cogs a normal spline causes, but bikes have been running non-sawtooth splines successfully for a long time.

    • Kirk Pacenti has some designs that utilize a 3 lobe shaped freehub. Think what a camshaft looks like, but the lobes are uniform, pressure is spread across a span rather than concentrated at a certain point(s). It’s freaking brilliant!

  4. (deleted). Its only a matter of time (maybe a year tops) until we can get the new shimano freehub from anyone and everyone. I dont get the nastyness, sram pulled the same thing and ppl got mad but now its the norm.

    • The XD driver patent is an open patent (Shimano says otherwise but what do you expect from the company that still refuses to make their cranks compatible with BB30/PF30/T47/386 and stopped making headsets when everyone went to the aheadset standard rather than pay a small fee.) . Shimano isn’t licensing this design so if you made one and it’s not that hard to make a new shell, they would get all upset and lawyer up apparently.

      • a 30mm aluminium made spindle is a non sense on a cranket. No wonder why Shimano and Campagnolo stick to respectively 24 and 25mm. Better use a stainless steel or titanium spindle than an aluminium one!

        Cannondale came with the 30mm because of they used a shorter than usual spindle. And because 30mm steel made would be to heavy they moved to aluminium.

        • What? All of the really light cranksets on the market – SRAM XX1 DUB, RaceFace Next SL G4, THM Clavicula M3 – use an oversized alloy spindle. Name one MTB crank with a <1" steel or Ti spindle that's in that weight range.

      • King and White Industries both make BBs that allow you to use Shimano cranks with T47 and they and many more make BBs that allow you to use Shimano cranks with just about any BB shell in existence.

  5. I will buy Shimano 12 speed for 2 bikes the day I can get separate DT microspline freehubs. If that doesn’t happen, forget it. I’m not going to obsolete 2 Enve race wheelsets for an extra gear. But I trust that eventually this will resolve itself…

  6. I’m going to set up a DT Micro Spline Freehub exchange. Assuming DT charges a similar price for a micro spline equipped rear hub as an XD or HG rear hub, If you’re planning to buy a XD or HG rear DT hub, I’ll have you order the micro spline version instead, then connect you with someone who will pay a premium to swap freehubs. you get your XD or HG hub plus ~$50, and the other guy gets to switch to 12sp XTR for way less $$ than buying a complete new hub.

  7. In other words, not only are you locked in to Shimano or DT hubs for their cassette, but you can’t even convert your existing DT hub.

    So people who prefer Shimano drivetrains but happen to have an existing hub they are happy with are going to end up running an Eagle cassette on an XD freehub.

    Combined with the new chainring mounting pattern and tooth profile on the front end, you’ve made it so anyone with an existing bike is only going to run the shifter and deraileur.

    Good thing they didn’t change the I-spec… g*ddamit.

    Shimano’s target market for this launch is apparently people who will shell out for an entire new groupset, plus a rear wheel, or people who buy OEM bike builds at the XTR level.

    I am not an accountant, but this doesn’t seem like a good business decision.

    • I am an accountant, and really accounting has nothing to do with it. It’s marketing. They are targeting the early adopters who are willing to pay a premium to be the first guy/gal on the block with it. Everybody needs to just CTFD and be patient. Shimano isn’t going anywhere…..they have a HUGE market segment and as anybody who pauses for just a second realizes… about 12 months there will be more wheels with microspline than you can imagine. If you want to be an early adopter of new technology be prepared to shell out the $ for it. As I learned long ago…never buy the 1st release of something because rev. 2 (or trickle down) will be right around the corner. All our 11 speed bikes will still continue to work for the foreseeable future folks.

      • 6 months time and they (might) release the Di2 version, 12 months time the XT version and in two years (maybe) the SLX version.

  8. End of August there will be other companies with a 12 speed groupset out and actually available in the shops and you will be able to use the hub you already have. I know for a fact that one of the new players is bringing four levels of rear derailleur out at the same time no waiting a year or more for a reasonably priced version.

    Don’t let the big brands with their monopoly dictate, their time is coming to an end and couldn’t be happier.

  9. It’s only a matter of time before we could buy DT compatible microspline freehub body.

    We are not talking about Sram or Campy. Shimano is the industry giant, Shimano makes standard and the rest of the industry follow.

    Do you think companies of the like of Mavic, Chris King, Hope or Novatec won’t have a Microspline fhb in few months from now?

    • Only if Shimano license their patent to them (assuming it gets approved). Otherwise, those companies will be making Microspline hubs and rich lawyers, when Shimano sues them for infringement.

  10. Shimano you can kiss my rosy red saddle sores! I’m sick of your crap. You can’t get anything to market in a reasonable time, you’ll be a large part of the reason why there won’t be any local bike shops, and you’re going to try to make me buy a new f’ing hub right after the whole boost thing. I’m breaking up with you… It’s not me, it’s you. (deleted)

  11. Our guess. Shimano will slowly make this system available to more companies (Chris King, White Ind. not to mention Mavic etc). Their long play will be to make this the preferred industry standard and to marginalize SRAM’s system. By being super selective with who they license the system to they might be hoping not to get sued by SRAM if they ultimately don’t include SRAM in the licensing.

  12. From my perspective this all makes SRAM XD look even more appealing. I know there are plenty of SRAM haters out there, but this may prove to further help SRAM dominate the MTB market.

  13. Well, I think Shimano will be running into legal issues themselves, at least in the EU.
    The same laws that allow resellers to sell bundled software SEPERATELY from the computers they were originally sold with (resulting in very cheap prices for Microsoft Office) will force DT Swiss / Shimano to sell their spare parts. Hence the Micro Spline bodies will have to become available or somebody will be sueing Shimano/DT Swiss.

    Also, Shimano could be seen to be exploting an monopoly… another reason for a lawsuit.

    The other question is, what the patent actually encompasses:

    IF it is merely the interface with the cogs one could get around it by creating a compatible shape, that leaves out maybe three of those splines… or design a steel version with cutouts and ridges rather than grooves (like Onyx Racing Products Cyclocross hubs) … or have an Aluminium Body with steel splines inserted into the body via V-grooves …

    There are countless ways to circumnavigate a patent without infringing on it, while still staying compatible.

    I hope the small players in the hub market are already looking into their options:-)

  14. why is everyone freaking out? You cant even get the XTR components until fall at the earliest (and based on shimano’s other launches, most likely winter or spring till theres actually available stock). By then the patents and lawyers will have worked it out and you’ll have all the stand-alone microdrive fhb you can shake a chainring at.

  15. Any news yet on whether this freehub might be available on 135mm QR? I can’t find out anywhere. I have seen that the new XTR hubs from Shimano are not available in this flavour. I’ve got a 10 year old titanium hardtail and the new M9100 1×11 would be perfect for it.

    • I’m in the same situation. As of April 2019, still info on this.
      As far as I can tell there are no compatibility issues, the cassette is the same width as the 11 speed, so its just a matter of the 135mm end caps. For me, I want to see a QR9 option.
      Perhaps modifying an existing endcap? Or maybe when the di2 or xt kits are available?
      Fingers crossed we’ll also see the 11 speed cassette(with the 12 speed spacing).
      Seems myopic not to support such a large segment of the market!

      • Maybe for now this is possible to be done with dt swiss hub and a conversion cap to it.
        However I will definitely wait for micro spline on XT segment in order to consider it. And I can not imagine XT segment without a QR hub. This will mean that 99% of the bike tourers will not be able to use the new Shimano XT.

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