OneUp-Components-42T-Sprocket-green-Specialized-2013-Stumpjumper-FSR-Comp-EVO 29- cassette- Looking for the wide range performance of XX1 but can’t afford the price tag? At OneUp components they believe in working less and riding more which is why they came up with a solution to that very problem. As their debut product, OneUp is essentially giving your cassette an extra life with their 42t replacement sprocket. Designed to fit on your standard 10 speed mountain bike cassette, the sprocket offers the super low range of the 42t cassette without having to make huge changes to your drivetrain. Intrigued? Shift past for more! OneUp-Components-42T-Sprocket-green-front Thanks to the advent of high quality non-drop chainrings like Wolf Tooth Components, drivetrain experimentation is at an all time high (at least for me). While it is possible to go 1×10 with a standard Shimano or SRAM 11×36 cassette, there are definitely times that a wider range would be welcomed – which is why the XX1 cassette offers 10-42t. The OneUp components sprocket won’t get you that 10t, but it will bump up the low range to a tractor pulling 42t. Built to use a standard 9/10 freehub body, the 7075-T6 sprocket includes 12 shift ramps CNC machined into the surface that are optimized for an 11-36 cassette. Once adapted, the net weight increase for the cassette is 51g and offers a 17% range improvement in the gearing. OneUp-Components-42T-Sprocket-Instruction-Sheet-01_grande Just how do you go about adding a 42t sprocket to your cassette? Well, essentially you are removing the 17t cog and replacing it with the 42t. There is an included spacer that must be positioned differently if you’re running SRAM or Shimano, but the directions make it plenty clear. In the case of a Shimano M771 11-36 cassette, this takes the gearing from 11-13-15-17-19-21-24-28-32-36 to 11-13-15-19-21-24-28-32-36-42. Will you miss that  17t? It depends on the bike, your gearing, cadence, etc. – but we hope to find out soon. OneUp’s 42t is compatible with most 10 speed medium or long cage derailleurs, as long as they offer enough chainwrap capacity for your selected gearing (largest rear sprocket – smallest rear sprocket) + (largest front chainring – smallest front chain ring). It should go without saying, but depending on your chain length you may need to add a link due to the bigger gear. As for the cassette, OneUp is compatible with the folloing 10 speed models: Shimano   

  • XT (CS-M771-10 11-36)
  • XTR (M980 11-36)


  • X5 (PG-1030 11-36)
  • X7 (PG-1050 11-36)
  • X9 (PG-1070 11-36)

OneUp points out that the Shimano Deore, SLX and SRAM 1080, 1090, and 1099 cassettes are currently not compatible with the 42t adapter sprocket. Compared to something like the General Lee 25-40T cassette adapter, the OneUp sprocket fits both SRAM and Shimano cassettes with the same part, and retains more of the original steel cassette gearing. Like the XX1 cassette, only the largest, 42t cog is aluminum which helps to maintain drivetrain durability. Also, due to the nature of the OneUp sprocket’s design since the lowest cogs rarely are worn out, you can replace the rest of the cassette while keeping the OneUp for future use. OneUp-Components-42T-Sprocket-green-Specialized-2013-Stumpjumper-FSR-Comp-EVO 29- drievetrain-

The OneUp 42t sprocket is available in black or green with the MSRP set at $100. The first sprockets are shipping out in January and will ship anywhere in the world for free. Check out OneUp on the web for additional product info and to place your order.


  1. John K. on

    You must be joking! If you remove the 17t cog, the gap between cogs isn’t proportional. With a 11-13-15-19-21-24-28-32-36-42 cassette de gaps will be 2-2-4-2-3-4-4-4-6. You have 4 teeth gap between 15-19, and 2 teeth between 19-21.

    If you want a good proportional cassette, you have to remove 17t and 19t cog, and replace it with 18t a 42t cog. The new gearing will be: 11-13-15-18-21-24-28-32-36-42 with proporcional gaps: 2-2-3-3-3-4-4-4-6.

    I think Shimano and Sram could make a 11-42 10v. cassette with 11-13-15-18-21-24-28-32-36-42 gearing.

  2. Drakche on

    Awesome idea, but 100$ for a single cog.
    whose manufacturing costs probably 15$…
    This is taking it too far. I really dislike the trend of manufacturers trying to cash in on some stupid hype.

  3. Kristina on

    Nice color. But the gearing is terrible. The jump from 15t to 19t cog is more than 26%! We sell our rebuilt 10speed cassette 11-40t with gearing 11-13-15-17-20-23-26-30-34-40t. Complete cassette for less than 100Eur.

  4. oratioh on

    Agreed this is an awesome product, and more cost effective than the General Lee cassette. But $100 for a simple CNC’ed single cog is BS, in fact cog for cog this is more than the infamous XX1 cassette. Come on guys

  5. Lawman on

    You can get single shimano xt 16t cogs as well to tighten the mid-range ratios a little bit, so you end up with 11-13-16-19-21-24-28-32-36-42. Would work on either the xt or xtr cassettes and they cost like a £5

  6. momo on

    Well, I could not justify the price of General Lee. And now… 100$ for a cog!? Please Shimano, bring us a native 11-42 cassette so we can get rid of this stuff…

  7. Eddie on

    Pretty much the same product made out of stainless has been available for months for $35 on ebay. A lesson in the power of marketing I’d say.

  8. 57-180 on

    So old it’s new again. Brought me right back to the 90’s and the Ritchey 2×9 drivetrain. Solid idea. I’m always amazed at how many things show back up that Ritchey dabbled with in the past!

  9. Matt on

    I would strongly encourage anyone complaining about the price to design, produce, package, and market something similar for less than $100. You clearly know better than these guys how to do all of this so very much cheaper, and I’m sure your expertise will be very much appreciated by those looking to save a few dollars.

  10. mike on

    yes somebody went unto business for profit. how shocking. bunch of whiners if you cant afford it then maybe you should consider a different hobby but last i checked there are plenty of affordable parts. and eddie provide this link you speak of because i cannot find it.

  11. Sevo on

    Price is fair. Few things to consider here:
    -Small Company=Small Batched.
    -In CNC, lower quantities=higher prices
    -Compare that a Wolftooth 44t chainring is $84
    -Compare: Rotor ss Q Ring is $140 for
    -Note: Cutting the splines isn’t as easy/cheap as you think
    -Nor is cutting in shift ramps

    Also let’s not forget that currently a 10-42 cassette will cost you $340, and you need to then get a special free hub body (if your hub has that option, if not you’ll need new wheels, if it does that’s typically $90+). Oh, and that is only available in 11 speed. Which means you’ll also need a new chain, shifter, and rear der minimum. Plus a Woolftooth chaining or similar starting at $40-$50.

    $100 for a ring that lows me to keep everything I have already except my 17t cog?? Sold. Sign me up. But I want mine in gold to remind me it saved me money.

  12. Kark on

    There’s some good comments here. Nice!

    The stainless unit via ebay looks like it would shift like garbage tho. No ramps or pins to help with shifting and the tooth profile looks quite different than any I’ve seen. It’s not comparable to the involute patterns of non-shifting ansi sprockets and it’s not comparable to the more open pattern for cassetts and chainrings so where did it come from?

    Thanks Kristina and John for good points r/e the gear spacing and alternate solutions. The Werke site unfortunately is a bitch to decipher tho.

    I like the idea of the oneup solution but I think would prefer to go to a 40t vs 42t

    In general tho adding a few teeth to the back would allow me to go larger with a single chainring for more top end which could be nice.

  13. Tim on

    These guys are smart- they’ve priced the product high enough to make themselves money (people do business in order to make money), and low enough to save you hundreds of dollars compared to getting the “real” SRAM XX1 drivertrain.
    The steel one on eBay is a cheap and probably effective solution, but not as light as this one.

  14. JW on,38&RZ=11,13,15,17,19,21,24,28,32,36&GR=DERS&KB2=32&RZ2=11,13,15,15,19,21,24,28,32,36,42&GT2=DERS&UF2=2120&TF=92&UF=2120&SL=2

    I’m in doubt. My bike is a XTR & XT mix. I won’t go to Sram, but I feel 1×10 (or 1×11) is the way to go for me. The Lee adapters didn’t convince me because in my experience experimental drivetrain combinations never shift as good as the original parts working together + less durability, …

    100$ is a lot of money knowing you get added range but loose some good shifting performance. And who knows what Shimano will bring out in 2014. Better save the 100$ untill it is clear how Shimano will respond to XX1 ??

  15. Kurt on

    I’m running a similar setup a friend made me as a hobby piece. Simply removing the 17T cog will give you a weird drop. I took off both my 17 and 15t cogs and replaced it with a 16t cog from an old 9 speed cassette I took off. Instead of going 19-15-13 now, I go 19-16-13.

  16. Alex on

    I’m sorry can we just lose the 11t cog and put in the 42? I can’t remember the last time I used mine.
    Ultimately aren’t we free to choose which cog we give up?

  17. Rich on

    @alex, you could lose the 11t but you would need to find a 12t cog from a 12-something cassette. You need one with the serated surface for the cassette lock ring.

  18. Ian on

    I think Shimano is crazy not to engineer a response to XX1, but… in Shimano land, front derailleurs are king and they only see 1X systems as a solution for DH bikes. I hope I’m wrong but I don’t think we’ll ever see a real trail worthy 1X system from Shimano, more than likely we’ll have internally geared XTRi2 but I bet that’s another 8 years away at least and will only be available to the ultra rich. All of these aftermarket solutions are cool, but on paper, they don’t seem super stable to me. If a rear derailleur wasn’t engineered to ever think about a 42t cog… I understand chain capacity so spare me on those dynamics.

    however, for me, $85 would be worth it to ditch the FD and maintain a reasonable gear range – I hate to admit it, but seeing someone like RaceFace produce a more affordable option is probably the next step. They seem to own that 1X market now with that NW chain ring. That silly thing is the best $50 I’ve ever spent on a bike and I would be hard pressed to give the little companies any of my hard earned money now. These smaller companies have to realize what they’re up against, it’s a lot like opening a bike shop in a saturated market only crazier. I wish them well, if it gets good reviews when it’s on the trails for a bit, I will buy one.

  19. James on

    This looks like an incredibly bad idea without a carrier to spread the load out. The top 3 gears on any modern cassette are on a common carrier to spread out the load so that the gear doesn’t dig into, score, and eventually jam/slip on the cassette body. Even with a steel cassette body I wouldn’t use this, as the load will be incredible with a 42t ring. There are already much better 1×10 stop-gap products avail.

  20. OneUp Components on

    Thanks for all comments. Please checkout our compatibility and installation website info for answers to a lot for these questions.

    Specifically regarding the freehub load comments we have close to 4mm of spline engagement. This is very similar to the engagement between XX1 and an XD driver.

  21. Simon on

    I actually think this is a pretty elegant solution. I’d expect it to last longer than a couple of cassettes so the cost of ownership over time will be lower than buying full cassettes

  22. Matt on

    To those saying drop the 11T and use a 13T smallest cog:
    42/13 = 3.23 (323% range)
    This is a smaller range than your existing 36/11 (327%).
    It would be easier and cheaper to just fit a smaller chainring…

    The point of this product is to give you a 42/11 = 381% gear range

  23. Jason on

    I love it, great idea…for a 1×10 set up this is a game changer. As for the cost!?!? 100 Bucks, (85 with the promo), that’s not bad, a lot of people I know spend 85 dollars on tires….that’s a bit ludicrous don’t ya think? So go out to your bike and add up how much you have in Rubber on your hoops, then compare it to a sedan tire, or even a motorcycle tire, then we cant talk expensive.

    But first I’m commenting directly to OneUp, as I have a question. Will you guys be offering in the kit a replacement for the 11T instead of the 17T, or will you supply the info needed and part numbers to do that swap instead of the 17, IMO this would be great for marketing, as it allows the customer to chose what jumps he or she would like to make, with a result in making your product even more appealing.

    My reasoning is this;
    Yes I see on paper that you will have less “Range” doing it this way. However, I’ve yet to ride my bikes on paper, but I hear it’s super fun. I unfortunately ride my bikes on dirt, up hills, in the mud, over rocks, and downed trees and all that mountain biking type stuff. So with that said, I rarely ever use my 11T ring, save for traveling or storing the bike to take some tension off the derailleur spring. So I would certainly be game to replace a cog I don’t use, for one that I certainly will with a 1×10 set up, (your 42T).

    Also I gave some thought to the speculation of the ring digging into the free hub body. Correct me if I am wrong, which I probably am, but while in a granny gear, ie the 42T isn’t it quite easier to pedal, so essentially you are putting less torgue into the drive train at this taller gearing? Thus lessening the stress on the drive train. Whereas if you are in smaller gear it takes more physical force to move the pedals thus that force is transfered through the drive? Further thought brought me to an idea that this 42T will not be used that often, so then even lowering the risk for free hub injury if you will. Now that’s just arm chair hearkening back to High School Physics there, nothing concrete, but just a thought.

    To OneUp, thanks in advance, I hope you can respond to my question.
    To interweb engineers and number cruncher’s….keep riding, it’ll make ya happier.

  24. OneUp Components on


    Always glad to respond.

    First regarding the 17T. We chose the 17T for a few reasons. First, it exists and is removable on all compatible cassettes. Secondly, removing it results in the lowest resultant percentage jump between the adjacent gears. Some cassettes, like the 1030 for instance, have other free gears that could be removed instead, to tune it differently.

    Regarding the 11T. We do not plan on creating this simply because we are looking to add range.

    Regarding the freehub load comments. We have close to 4mm of spline engagement. This is very similar to the engagement between XX1 and an XD driver.

    Thanks for taking the time to comment.

  25. 24s on

    I don’t agree the solution of taking off the 17. Better way is to get single shimano xt 16t cogs as well to tighten the mid-range ratios a little bit, so you end up with 11-13-16-19-21-24-28-32-36-42. No stupid gap between the lowest cogs.

  26. RickT on

    @Alex: If you never use your 11T and you find your 36T not low enough, maybe just get a smaller chainring! You will find both your 11 and 36 cogs more useful, as well as improving clearance and weight a tiny smidge 🙂

  27. M.E on

    Certainly some nice “creative”marketing on their website: “The OneUp Components 42T Sprocket gives you 90% of the benefit of 1×11 systems at 10% of the cost”

    Sounds good, but your current 11-36 cassette will give you “80% of the benefit of 1×11 systems at 0% of the cost”. Dude that’s like infinity % better value!

  28. hellbelly on

    I think this looks awesome. A simple and smart design. To the posters b*tching about the cost, buy something else, build your own or better yet STFU and go ride.

  29. drkrvr on

    Definitely not a full professional solution. Seems to me kinda DIY. Pics/web are nice. Color/design nice as well. Any references? Reviews? Have to admit and thnx 1up that there is a next “alternative” to XX. It is just a peace of aluminium 7075 anyway, not a Francium (25g in the all Universe :). Is it?

    My proved solution for 400m-1500m / 1300ft-5000ft mountains since 2011 (snow, winter, summer) 26er bike setup:
    chainring – front Surly steel 33t / no chain guide, 2 drops in a city 🙂 / der. – XT SGS 2008 / casette – Deore 12-36 / shifter – 1pc XT 2008 / chain – 1×9 Campagnolo C9 / other – stronger legs… So I built one, I did it .)
    Total cost cca. 70.- Eur/ 95.- USD (chain C9 + cass. + Surly). Components are HQ off-civilisation purposed. Weight – not the lightest, but it is built to last (steel), not paper… Full HT 26er, year 1999, weight with Magura HS33, RS SID 2008, CB Eggbeater and tyres cca. 550g per 1pc is cca. 11,3kg / size L / Aluminium 6xxx grade frame. Ok?

    Definitely do not like to change gears up/down all the time, will wait for complex solution (Shimano?) Prefer 1×8… WTF 1(2)x11(12, 13, 14, x)? Why? Chain wide? Lifespan? Common sense, sry? Better to choose a car or e-bike 🙂

    Interesting alternatives:

    and 40t cog for 72.- Eur from UA:

  30. isaac on

    Lets be honest here, if you are pairing this up with an X5 cassette you aren’t buying an XX1 or XO1 parts group any time soon. I like the big green anodized cog, I might get one for my single speed.

  31. Catch22 on

    @What? The different freehub body on XX1 is smaller to accommodate the 10t cog that won’t fit on a standard freehub body. As a whole, the XX1 freehub bodies are a downgrade from a traditional freehub due to smaller diameter and the resulting smaller bearings.

  32. Alex on

    $100 is good deal – I just bought a 29er Norco Revolver and it happened to be a leftover from 2012 so I got it for a good price – great frame, but slightly heavy parts (X5/X7) – I am going to end up upgrading it as I go. I’d love to go X01 or XX1, but when I add up what I’d have to do all at once to go that route (rear wheel with XD driver, 11s RD and shifter, crank, chain), I can’t afford that just from a cashflow perspective – it’s too much all at once. But I can afford to do it bit by bit – keep my wheel, add the $100 cog, take off the FD and shifter, get a Race Face Wide-Narrow ring, I am functionally (if not weight-wise) most of the way to where I want to be. Somewhere down the trail, after I wear out the rear wheel or kill the RD, I can perhaps afford to do 11s with XD. In the meantime, this is a great solution!

  33. drkrvr on

    This is the same idea I have discussed with a small custom-bike producer in CZ. Superb idea to use a simple adapter for a common freehub and to combine it with any steel/alu/ti/carbon/… 104 BCD (front) chainring. After it wears out it is enough to replace only the chainring itself. Eco solution as well. Perfect! If only 1 chainring wears out there is no need to replace the crank arms as well (trendy to save weight by compacting different parts to all-in-one-piece).

    Tip1: Could be good to make a FSA compatible or different BCD adapters as well. Thnx.
    Tip2: Any producer/lab – please try to figure out 3D printing tech and heavy-duty cog materials…

    Similarly like Charge started with frame parts

  34. Chris on

    What makes an SLX cassette not compatible with the OneUp cog? If it was compatible you could take the 17t and 19t out and replace it with an 18t, and this would give you very even splits between the cogs throughout the cassette. Unfortunately for this application the XT and XTR the 19t cog is attached to the carrier and as a result you can’t remove it. While this might not be the solution for everyone, it’s certainly a viable option, and the more options that are out there the better.

  35. Chris on

    What makes an SLX cassette not compatible with the OneUp cog? If it was compatialbe you could take the 17t and 19t out and replace it with an 18t, and this would give you very even splits between the cogs throughout the cassette. With the XT and XTR the 19t cog is attached to a carrier and as a result you can’t remove it. While this might not be the solution for everyone, it’s certainly a viable option, and the more options that are out there the better.

  36. Lawman on

    Some people really have missed the point of this! Too many arm chair engineers and dismissing things before they’ve even tried it. I for one think this kind of product is a great idea and can’t wait to try one out.

  37. Jeff on

    Shimano or Sram XT or XO level 39 tooth cassette would cure most ill’s on this issue, and still allow people to use their current derailleur without adding any links to their chain and the torque fear would be eliminated as well. Soooo, get on it!!

  38. Ian Andrew on

    Can i order your Sproket in Red rather than the Black or Green option(don’t mind paying extra for a special order) and also can you explain how my Sram X0 Rear Mech will clear the 42T Sproket,has Sram say the Max Teeth my Mech will clear is a Max 36T Cassette.


  39. drkrvr on


    3×9, 3×10 – too heavy, to much gears, 9sp chain with better lifespan
    2×9, 2×10 – good compromise for everyone and every terrain
    1×9, 1×10 – for “lazy” bikers with stronger legs, weightweenies, lower range purposes


    SRAM 1×11 – superb idea for professionals (price, lifespan?)
    PROTOTYPES HOPE 9-36, ….still prototype and other protos
    XYZ Co. adapters – buy a cog (set of cogs) and try it out – for DIYers, experimentators
    SHIMANO – please do not sleep
    FULL CASSETTE – (best deal IMHO for the price), Recon, KCNC, … (price…)

    Forgot something?

  40. dislivello on

    Problem will axle hub or pawl /rachet ring…w 42 need to have troule axle and hub resistence 40 kg m torque.. shimano hub are not available…i thinks

  41. Edwin Santiago on

    Its a great cog. Im running a 3-9speed. Change the 11-32 to a 12-36 9speed remove the 12t cog and It works perfect. Cassette tooth count is 14-16-18-21-24-28-32-36-42t ( 2-2-2-3-3-4-4-6 ) this setup a low me to climb much better for a heavy rider.

  42. xw on

    OneUp Components or anybody that knows,

    I have a x0 type 2 rear derailleur (I don’t know if it’s a medium or long cage length). I have x0 2×10 39/26 up front and 11-36 cassette in the back. I know long cage length rear derailleur will work, but will a x0 type 2 medium cage length rear derailleur work as well?

    Thanks in advance


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