Put SRAM XX1 spider and chainrings on standard X0-X9-X7 cranksets to make your own 1x11 drivetrain

It doesn’t take much prognosticative power to deduce that this trickle down was only a matter of time, but now we’ve heard from several of our insider sources that an X0 1×11 group is coming.

Can’t wait? The good news is you can make your own now without giving up your current X0 (or X9/X7) cranks. As illustrated here, the XX1 spider will fit on existing SRAM mountain bike cranks with the splined spider mount. Sorry XX fans, that means you’re out of luck for this conversion.

Given that you can already find a good variety of 104 BCD 1x chainrings or direct-mount chainrings that’ll eliminate the spider and save grams (here, here, here and here), we’re still figuring out the “why” of this particular hack. But, it does show how easily SRAM could transition their top-tier XX1 1×11 speed components to the lower level groups…

UPDATED: Check out Marc’s BMC with X0/XX1 mash up at bottom of post.


The spiders use the same spline pattern, regardless of whether it’s BB30 or GXP. This spider came off a BB30 XX1 crankset and fits like a glove on a two-year-old GXP X0 crankset.


The upside to using a SRAM system, whether you piece one together with an existing X0 (or X9, or X7) crankset and XX1 spider/rings or wait for the anticipated full X0 system, is that you can easily swap chainring sizes without having to remove the crankset. The wider arms may also provide a stiffer base for the chainrings, something we’ll take into account as we’re testing units from Wolf Tooth Components and Absolute Black over the next couple months.


Claimed weight for the X0 GXP crankset is 790g and the driveside accounts for about 450g. It drops down to 378g with the XX1 spider and 34T chainring.


The current XX1 chainrings retail for $94 to $131 depending on size, and the spider is also available separately aftermarket, though we’re waiting to confirm MSRP. Update as we get it, as it’ll be interesting to see what the price of piecing together a system is.

BMC Trailfox with XX1-X0 1x11 drivetrain mashup

Per Marc’s comment below, the XX1 and X0 crankarms look strikingly similar and could very well be the same cranks just with different graphics.


  1. David, don’t take this as a personal attack, but you need to look a little harder. I can find XX1 almost everywhere online. I also called around and two out of the 4 bike shops I called around Denver had them in stock.

  2. To be fair, it is hard to find. Even here in the lower mainland I couldn’t find a set, Norco had sold out their next two orders before they had arrived. Lambert had a 3 week lead time. I ended up going down to Bellingham to find some at Fanatik Cycles

  3. Just because your shop doesn’t have it, doesn’t mean it’s sold out. As others have said, QBP is currently in stock on most major XX1 components.

    Trickle down makes a ton of sense, because SRAM, like most component makers, make the bulk of their money at the OEM level. There’s a lot of interest on the floors of most bike shops, but little willingness to throw down the money. However, relatively inexpensive carbon and aluminum XX1 (or XX1-style, depending on SRAM’s nomenclature) hardtails are going to light up sales pretty quickly.

  4. FWIW: When I weighed spiderless X0 and XX1 cranks, there was a 5g difference in favor of the X0 (in the noise, but probably accounted for by the helicopter tape that comes on the XX1). The retaining hardware is also slightly different, but that could be a running change on both groups. Why swap? The X0s were blacker 🙂

  5. by the way, XX1 Chainring is pretty important to the system for keeping the chain on with out the watcher. So unless those spiderless rings are XX1, the wont work correctly. not that they wont work, they just wont work correctly

  6. Digi – some of the other chainrings are using a wide/narrow tooth pattern, and another benefit of that design is allowing for much smaller chainrings. That said, SRAM offers a 28T, and I don’t know anyone that would need anything smaller than that when combined with the massive XX1 cassette.

    Also, forgot to mention in the article: I spoke with SRAM’s drivetrain guys at Sea Otter and they did say that there’s so much demand for XX1 that, on one level, it doesn’t make sense to dilute it with a lower cost offering. But, Gravity makes a good point about the OEM placements wanting to take advantage of the hype but offer something at a lower price point. That, and bringing more people over to the system early on keeps them off competing products…and it’s a pretty sure bet their competition is well aware of the success and wants some of that action.

  7. Can anyone confirm whether or not SRAM road cranks (S900 / Force22) will work with these spiders as well? I know there are differences between the BB30 and GXP spiders, but are mountain and road the same? (Hoping that the only obstacle to running a new 165mm Force22 set of crank arms on a mountain bike is whether or not it clears the frame due to the narrow Q-factor).

  8. If you’re buying new, I don’t see the big deal about the cranks. Where the trickle down needs to happen is on that $400 cassette!

  9. I’ve been looking to convert my old SRAM 3×10 X0 GXP cranks to 1×10 using something like NSB’s direct mount chainring. Has anyone tried to convert a 3×10 X0 to use the XX1 spider?

    Reading this article it looks possible as the 3rd (small) chain ring still attaches to the X0 spider not the cranks themselves and it would allow me to go to 1×11. What I don’t know is if the 2×10 and 3×10 X0 spiders or cranks actually have some differences.

  10. Leonardi Factory makes a General Lee cassette adapter that goes 25-29-34-40 keep your 10 speed chain, and everything else.

  11. Can we get a chainline measurement with the bb30 spider on the gxp crank? I think they should be different, but that could be good for getting more clearance with the xx1 ring.

  12. I heard SRAM has a patent application on the fat-thin front ring design and that they are “encouraging” manufacturers of fat-thin rings to take a license, is that true?

  13. I’m running MRP Spiderless chainring ’36T’. Weight is 365g for the combo XO crankarm driveside/Chainring (against those 378g above with 34T).

  14. @Bill: Patents which cover the “big-thin”-thing are were already registered 1979 and before. Thats basic patents for transmission and chain drives which are mostly outdated for years. So if SRAM got patents, it would be pretty easy to get rid of these patents (in the US and Europe)

  15. I think SRAM would be making a mistake if they didn’t release X01 and X91 drivetrains soon. Those of us who want to run the 1×11 on multiple bikes but can’t afford two XX1 setups would buy them up quick…

  16. Jason,

    As far as we can tell, the various X0 GXP arms and spider interfaces are identical to those used on 168q XX1 arms. The BMC above uses an X0 triple crankset with the XX1 spider.


  17. GXP and BB30 spiders have slightly different offset, but you could probably run them as a single pretty okay due to the flexibility of the chain and the lack of shifting needed.

  18. i’ve been on XX1 since October. Great system. I moved my XX1 spider and ring to a X9 crank to get a 180mm crank arm (unavailable in the current XX1 kit). i think there is a subtle chain line difference. There is a noise from the front ring now as the chain rides the fat/thin teeth. it is an audible click-click-click. I use it to keep my power steady as i’m climbing. if one leg is slacking off (left leg you know who you are!) the noise decreases in volume.

  19. Sorry, but I see no hack here… the crankset is the least expensive part of the whole group. Spare front chainrings, cassette, freehub body are the critical parts that need to trickle down to a more affordable price… the only scenario in which this spider swap would matter is if you need a crank arm length other than 170/175 mm… I bet there is close to no money saved by buying a XX1 spider (IF available) and XX1 chainring compared to the whole crankset.

  20. randy wolf tooth makes a 104bcd as well as sram spiderless. i run a 32t spiderless on my xo cranks with a clutch derailleur. I have not dropped a chain yet. its silent

  21. I’m using the NSB spiderless 27T GXP on SRAM XO with XT 11-36 cassette and Shimano Zee (Shadow Plus) derailleur. This setup is standing up to tough conditions (weather, climbing, trail, and style) and has very, very rarely dropped chain. I think that “plus, minus, plus, minus” tooth structure is a bit overhyped, as well as the 11th (10T) cog because I don’t need to surpass 25MPH on any singletrack descent.

    I’m looking forward to a trickle down in the direction of a 11-42 10-speed cassette.

  22. Just put an XX1 spider on an S900 crank to see if it would work on the cross bike. Works a treat on my Giant TCX Adv! I’m thinking this is going to be a popular option for cross!

  23. “In the case of the X-Sync technology, we are well aware of a 1979 patent describing a sprocket for agricultural conveyer equipment and are confident that we will obtain enforceable patent rights over this reference”, announces SRAM.

    “Accordingly, competitors should consider whether their product is copying the agricultural conveyor sprocket or SRAM’s XX1 chainring with X-Sync technology.”

  24. Great comments!

    @randy – great idea.
    I ran no chain watcher on a Renthal 33t with XTR Shadow Plus rear mech moving a X10SL across XX 11-36t cass. Was awesome, but would drop, only over rough stuff when not pedaling.
    @Tes – similar results. Very rarely dropped the chain, but that’s a problem ‘cuz you don’t podium when you have to pick up the chain. Went XX1 in Jan, haven’t’ dropped the chain once. I did gain weight thou. RD, cass, crank, chain; heavier. Either way, chain is on, and the 11-42 can get it all. I can hang on road group rides, and stay seated for any climb (went 36t up front).
    @JD The cassettes are a grip, But! if you take care of it and your chain you’ll get you’re money’s worth. Over two years, I put more than 5000 miles on my XX cassette, and then passed it to my friend when I upgraded, and it still hasn’t skipped! Kept my chain ‘ultra’ clean tho. Word.

  25. @Bill:

    Well, I’m sure, that this patents won’t last in front of the court. Even Apple has a tons of problems to hold their patents, because some other guys were quicker.

  26. @Max: Hope you are right! It would be a shame if SRAM limited competition. I can just imagine Shimano comming back with a nice 1 x 11 system. Infact I have a catalogue from a Taiwan hub maker that has Shimano 11 speed MTB compatible cassettes as an option on some upcoming hubs…

  27. Hi,

    Did anyone already tried the other way around?
    So a 22/36 (64/104) sram XO spider on a XX1 crank arms?

    Would be great if this would fit 😉

    Best regards.

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