Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x

Just when you thought it was safe to buy into a new drivetrain – in swims the Shark. Perhaps trying to lure over the remaining 1x holdouts, wide range cassettes are getting even wider. While we know SRAM has something of this magnitude up their sleeve, it’s OneUp who is first letting the Shark out of the bag.

While OneUp is no stranger to cassette adapters which modify Shimano cassettes to provide wider range, the Shark is a little different. Sold as a kit with a replacement derailleur cage and an 18t and 50t cog, the set is to be used together. However, if you want even more range – there is an additional 10t mini cluster that is compatible with a few different wheels already out there…

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-2

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-9 Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-6

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-11 Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-10

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-12 Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-7

Building on the 11-42t profile of the Shimano XT cassette, the Shark upgrade starts with a 7075-T6 aluminum 50t sprocket. Going on the freehub first, the 50t sprocket pushes the cassette out one gear which is made up by replacing the 17t and 19t cogs with the included nickel plated steel 18t cog. Due to its modular nature, the Shark can be used in this set up without the 10t mini-cluster for an 11-50t cassette with 11,13,15,18,21,24,28,32,37,42,50 progression. In this configuration, the complete cassette comes in at 505g. OneUp points out that in order to keep a standard-free hub body, this is the widest range cassette you can currently build.



We haven’t had a chance to check out the mini cluster yet, but when available it will replace the lower three gears to get down to a 10t as the smallest cog. This is smaller than the standard free hub body will allow, so OneUp worked with Hope Tech to create a non proprietary freehub body that will work with the 10t. Essentially the last three cogs are housed on their own carrier which threads into a shortened free hub allowing for either a 10-12-14 or 10-12-15 progression depending on the use. OneUp says that free hubs will be available for Hope, DT, and Stan’s hubs with more coming soon.

Called the MiniDriver, the technology is open to anyone to use or develop which means we could see this concept on the wheels and hubs in the near future. When available the 10t cluster will include a 10-12 cluster, 14 and 15t cog and the green lockring for $45. The OneUp MiniDriver which is 4.5mm shorter than a standard free hub body and is compatible with DT Swiss Star Ratchet hubs will sell for an additional $40. The Shark 50t sprocket and cage kit will run $125 meaning you could have the full 10-50t cassette for $210 plus the cost of the Shimano components.


Based on either the 10-50t or 11-50t Shark gearing, it’s clear what OneUp was after. Yes, there are some huge jumps in the cassette progression, but if it’s absolute range you’re after, look no further.

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-3

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-18 Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-4

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-5 Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-8

In order to fit that massive 50t sprocket back there, the Shimano derailleur is going to need some help. Compatible with Shimano 11 speed Shadow+ derailleurs, the Shark Cage increases the upper pulley offset by more than 50% to allow it to clear the 50t. Our derailleur came preassembled, but from our experience with the RAD and RADr cages, it’s an easy swap and utilizes the stock pulleys and hardware. Complete XT M8000 weight once modified with the Shark Cage came in at 281g.


If you’re not into the green look, there is also a full grey kit which nicely matches the stock Shimano colors.

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-28

Set Up:

It’s important to note that OneUp recommends using a chainring with 48-50mm chainline. If you are using a stock RaceFace Cinch set up as I was, that means you will need to use a different chainring to get away from the stock 51mm chainline.

Initially, when running the RaceFace ring if you were to back pedal in the 50t the chain would derail down the cassette. Switching to the 49mm OneUp ring solved the backpedal issue on the 50t cog, but it doesn’t solve the issue on the 42t cog – which seems to be a Shimano problem more than a OneUp problem. With the stock Shimano 1x drivetrain, if the chain is in the 42t cog and you back pedal it will also derail. This doesn’t seem to change whether that 42t cog is in the outermost position or shifted in by one spot. So while you can get it so that you can back pedal in the 50t and the 37t cogs without the chain coming off, you can not back pedal in the 42t cog no matter where it is on the cassette. It’s actually pretty impressive that you can back pedal on the 50t considering how big it is, and the extreme angle of the chain.

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-16

Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-19 Oneup one up Shark 50t 50 tooth cassette adapter shimano xt wide range 1x-20

Speaking of which, really our only criticism at the moment comes from the amount of noise the chain makes when you are pedaling in the 50t. Speaking to OneUp, they acknowledged the issue and said that they changed the angle of the lower pulley after their sample run and before their production run to make it run quieter. We should be getting in a new cage to verify, but it sounds like the production cages will have that taken into consideration.

As far as set up is concerned, once everything is installed, adjustment is straight forward. Thanks to the design of the Shark Cage, the derailleur will clear the 50t with B-tension to spare. Keep in mind that if you are modifying an existing drivetrain you will probably need a new chain – on our test Kona Hei Hei DL Trail we didn’t cut the Shimano chain at all out of the package. Bigger chainrings/longer chain stays may need more than one chain!

First Rides:

Admittedly, there have been rides on a stock Shimano 11 speed 1x group with the 11-42 cassette where I have wished for more range. But an 11-50t?

Right off the bat I was surprised at how well the whole system worked. Typically, my experience with cassette adapters have been that they worked, but not as well as a purpose built drivetrain. This may be the closest you can get at the moment to adaptive drivetrain perfection. The chain doesn’t hesitate up or down when shifting to the 18t or the 50t, and the somewhat normal B-tension adjustment seems to keep shifting relatively crisp. That isn’t to say that the performance is on par with SRAM’s XX1 or Shimano XTR, but it’s very, very good – as long as the production models offer a quieter ride in the 50t.

As for the usefulness of the 50t, it does take some getting used to. I really had to search for grades at my local trails where the 50t was needed – at which point it became more of a struggle to keep the rear tire from slipping. Because of that, I’ve already gone up a few teeth in the front (32 – 34) which provides more high end speed but still provides more low gearing as well. This seems to be the big payoff of the 50t – the ability to run bigger chainrings while still having enough of a low end to climb any hill that comes your way. Because of that, I have a feeling that 50t cassettes will have a lot of riders paying more attention to maximum chainring size on their frames in the near future.

So who is the ideal customer for the Shark? As an upgrade, the system makes a lot of sense for anyone wanting more range out of their current Shimano 11 speed 1x drivetrain (or anyone who may buy a complete bike with Shimano 1x in the near future). The Shark kit also seems like a real option for anyone trying to gain the widest range 1x drivetrain on a budget. SRAM has put out some mighty impressive 1x drivetrains at very attainable prices, but when it comes to absolute range the Shark has the 10-42 beat. And if/when SRAM does launch their 10-50t cassette, we have a feeling that it will be a good bit more expensive than a Shimano XT drivetrain with the OneUp Shark treatment.

Shark Kits are available for preorder now for $125 and will ship starting April 11.

Shark 50T Sprocket Tech Specs:

  • Cassette Progression: 11,13,15,18,21,24,28,32,37,42,50
  • Sprocket Material: 7075-T6 Aluminum (50T), Nickel plated hardened steel (18T).
  • Compatibility: XT M8000 11-42T cassettes (For Shimano 11-40 use the OneUp 45T sprocket)
  • Freehub requirement: Standard
  • Cassette range improvement: 19%
  • Colors: Grey or Green

Shark Cage Tech Specs:

  • Pulley Offset: 50% more than stock
  • Compatibility: Shimano Shadow+ 11spd rear derailleurs
  • Colors: Grey or Grey/Green
  • Shark 50T Sprocket and Cage Kit MSRP: $125 USD

10T Cluster Tech Specs:

  • Kit contains: 10-12 cluster, 14T and 15T
  • Cassette Progression:
    • 10-12-14-17-19-21-24-27-31-35-40 (11-40 Shimano converted to 10-40)
    • 10-12-14-17-19-21-24-28-32-37-42 (11-42 Shimano converted to 10-42)
    • 10-12-15-18-21-24-27-31-25-40-45 (11-45 OneUp’d Shimano converted to 10-45)
    • 10-12-15-18-21-24-28-32-37-42-50 (11-50 OneUp’d Shimano converted to 10-50)
  • Compatibility: Shimano 11-spd 11-40 and 11-42 cassettes and OneUp’d Shimano 11-45 and 11-50 cassettes
  • Freehub requirement: OneUp MiniDriver (or compatible)
  • Cassette range improvement: 10%
  • Color: Nickel Plated cluster with Green Lockring
  • MSRP – $45

MiniDriver Tech Specs:

  • Length: 4.5mm shorter than a standard freehub
  • Lockring Thread: M29
  • OneUp DT star ratchet compatible MiniDriver
  • MSRP – $40


  1. Technician on

    What I am missing here? I’m road biker (former MTB) and I don’t get which hills you’re gonna climb to need 50-tooth cog? At which speed? 2 km/h? What’s the reason?

    I switch to my 42/23 maybe once a month. The area where I’m living now is fairly hilly.

    • Wuffles on

      Thanks to transportation standards, roads cannot be built anywhere as steep as the trails you can ride on mountain bikes. A 20% grade is a very steep road climb, it is not particularly steep for a mtb climb. A steep mtb climb would be like 35% grade, with short punchy sections hitting 80% for a few dozen feet. Also, your surface is loose, rutted, and nowhere near as grippy as tarmac. It’s a rally hill climb vs a F1 track.

    • Luke on

      The point is that you are running a double and using the granny ring. Further down the article Zach talks about running bigger rings in the front. A 34/50 is pretty close to a 30/42 but then allows for the bigger top end. If any XC guys were worried about losing their double, this and the expected eagle solves it.

  2. sad on

    you can put a 30t up front and climb anything on 42t rear… wait wait, let me make feel it. you can make a single speed with a 42t rear and 30t up front. it’ll still suck on the flat/downs.
    50t rear let you have a 34t front

    • Eric Hansen on

      Yup. I raced 1x last year (with OneUp and e.13 components). This year I am back to 2×11 and loving it. When affordable syncroshift drops later this year, i’ll effectively have the same range and simplicity.

  3. goroncy on

    Back in a day I had this really cheap bike with some super cheap shimano cassette that had this huge granny cog. I always was like super exited when I saw those super expensive bikes with 3×8 drivetrain. Now there is this super big (deleted), excuse me cog again. The evolution sometimes is a strange animal.

    • will on

      Yessir, the old Shimano “Mega Range” cassettes. Or they might have even been freewheels. Only ever saw them spec’d on cheap hybrids…

      • TheKaiser on

        Although Mega Range cassettes looked monstrously huge back in the day, I think they were only a 34t big cog. Certainly no bigger than 36t. They looked huge because, while slightly bigger than the norm at the time, they were also usually 7spd cassettes/freewheels, so the jump was from a 28t or thereabouts, which made the relative difference much larger than most other cassettes at the time.

  4. Mike on

    Great solution for those looking for a 2×10 spread on a bike that can’t take a front derailleur.

    Remember folks, this isnt about being able to run 30/50, its about being able to run 34/10.

  5. Haromania on

    Some people, such as myself, will never own another front derailleur again. So I like seeing this stuff, but I suspect some cyclists just don’t yet grasp that not every product made is meant for every cyclist. Think of it like this, “If you like your front derailleur you can keep your front derailleur”.

  6. Sylvain on

    As Mike said, it’s about using 34/10. I have ran 11/42 with 30 ever since it came out. Won’t go back. Simplicity.

  7. Jami on

    I’m down. This panders to my love of taking stock bikes and making them not-stock. Also, for fatbikes! You can never have a low enough gear on a fatbike.

  8. Chris M on

    Is no one going to call out One Up out for introducing another freehub standard? Alas no, they made it anno green so everyone is just stoked it is color matched to their set of DVD forks.

  9. Michael on

    Chris, this uses a standard Shimano freehub body. There is no new standard anywhere to be found. And the forks you are talking about are DVO, not DVD. lol

    I like that this exists and have experienced where this would be beneficial in some areas and circumstances. particularly where you want a larger chainring to achieve a faster high gear, without sacrificing the low end for steep technical climbs. This does exactly that.
    Fatbikes, loaded touring, or singletrack trail riding with long fast stretches of road to get from place to place are places where this could be beneficial. For me and where/how I ride right now I am very happy with 11-42, but it’s great that this is available.

    • Chris M on

      Michael, The Shimano freehub body design was great back in the day of road clusters and steel freehub bodies. That day is gone. Unfortunately mechanics the world round are still wasting hundreds of hours hammering cassettes off alloy freehub bodies. So why are you happy about them preserving this interface? And yes, I know it is DVO. DVD just types and sounds so much better 🙂

  10. Michael on

    Ahh ha. You are talking about the Mini-Driver. Forgot about that bit. That’s for their 10T cluster. Interesting modular design they came up with though, using the same Shimano HG Freehub body, only shorter. At least its preserving the cassette interface pattern, and its an open non-patented design. 500% is a lot of range! Pretty wild what they came up with, and very creative.

  11. micahmarkson353878510 on

    If someone uses the Mini-Driver to build a 10 speed 10-42 cassette, that would be awesome! You can use a Shimano 10 speed shifter with either a OneUp RadR cage, or with a Shimano 11 speed derailleur, plus that cassette.

  12. Erich on

    I have no opinion on the actual function of these products yet, but I always appreciate a good joke name. As such, kudos to OneUp on fitting both ‘jumping the shark’ and Minnie Driver into your product line. Dad-joke aficionados world-wide salute you.

  13. Flatbiller on

    Do they need to color it in such a way that it screams, “I need all the help I can get!”? If I need a 50t cog, I want to keep that hella on the downlow.


  14. dave macdonald (@davechopoptions) on

    Any mechanic who is resorting to hammering sprockets off all free hub bodies is an idiot.
    Even if they have been under-tightened and gouged the free hub splines, you can remove them with no damage either by hand, or in extreme cases 2 chainwhips.

    In the short existence of the XD driver, I’ve heard of more issues with seized cassettes, than on a standard free hub body.

  15. TheKaiser on

    Is the mini-driver cassette body that they mention as an upcoming option to run a 10t the same as a Shimano Capreo cassette body? I don’t think Capreo ever went to 11spd, but since the thing is sorter with the extra cogs extending outward I could imagine it not mattering as much how long the cassette body is.

  16. ascarlarkinyar on

    All this expensive and heavy undurable crazyness just so you don’t have to run a front derailleur.

    My 3×9 works perfectly well, is lighter more range and one forth the price. Plus no big jumps in gears.

  17. CowtownCyclist on

    Wow. That is shockingly ugly. I think most pie plates aren’t as fugly as that. Are you sure this isn’t an April fools joke that some one let slip a little early? I’m all for 1x, but a 50 t. cog? At that point you are really starting to lose the benefit of ditching your second chain ring and front mech.

    • mr_godfrey on

      I believe it is a fundamental of empirical engineering that chains are more efficient (less lossy) that gearboxes. I think it’s something like 98% vs 95%. That’s too much to give away for a human powered vehicle most of the time. A radical technological breakthrough would be required to overcome this difference.

  18. bearCol on

    The range sounds great but considering the added price, weight, and cage length I’m not interested. I wish the bike industry would focus on gearboxes rather than trying to accomplish everything via a big cassette. Any company that can decrease drag and weight over pinon’s gearbox will one up everyone. I believe gearboxes would take over 90% of the market when those two things are refined. I should also add shifting under a load and maybe an alternative to grip shift which most do not like it seems. Shimano missed the 1x boat big time, they could own the market again with a gearbox.

  19. Max on

    Nice!!! I can definitely see this baby coming in very useful for alpine/backcountry missions, especially multi-day ones with a pack. Put this on a fat bike and it will go up anything! I’ve been using the OneUp 42T on a 10 speed cassette for a while, usually put on a 28T front for backcountry missions – excellent ratio but I remember times on long steep slogs were I kept searching for a lower gear only discover that was it… oh the burn. Stoked to try this!

  20. Kevin on

    You mentioned needing a 49mm one up chain ring for the stock race face cranks. I don’t see that offering on one up’s page. Could you point me in the right direction?


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