OneUp Components releases the Shark, 10-50t upgrade for Shimano XT

500% gear range for Shimano 11-speed 1x users

With rumours circling of a new SRAM 10-50t 12-speed groupset, OneUp Components has taken the first bite with its new 50t upgrade kit for Shimano 11-speed. With such a number of teeth, the upgrade has been appropriately named the ‘Shark’. This comes just weeks after Shimano announced its own 11-46t cassette to help gain some credibility in the booming single-ring market.  


Boasting a huge 500% range with a single chainring, Shark is designed to extend the range of a stock Shimano 11-42T cassette by almost a third. Shark and its 50T sprocket is sold along with a derailleur cage kit, while retaining the stock 11T small cog of the cassette. A secondary and optional kit takes it the step further and uses some tech trickery to introduce a 10T cog to a Shimano cassette, albeit with a new freehub body. Both options can be used independently of each other.

A look at how the gear ranges stack up. even without the 10t cluster kit, the 50t shark offers a huge boost:

The Shark has range

Shark 50t Sprocket and Cage Kit

Claiming to be the widest range cassette available for use on a standard freehub body (any 8-9-10sp Shimano freehub), OneUp suggest that running Shark with a 4-tooth larger chainring will increase your gear range at both ends.

OneUp are no strangers to such upgrades, and we’ve been running a OneUp 45T sprocket with a XTR 11-40t cassette with great success. However, this 50t certainly takes it a step further and so OneUp has designed its own derailleur cage to handle such an enormous granny cog.

Designed to work with Shimano XT M8000 11-42t cassettes, Shark’s 50t cog offers a 19% improvement in range. Made of 7075-T6 aluminium, it’s available in either a matching grey or loud green.

This is the shark 50t upgrade kit, it includes the 50t cog, a hardened steel 18t cog and the alloy derailleur cage :

It’s not just a cog, it’s a kit

In order to fit a 50t cog to outside of the cassette and keep it at 11-speed, the stock 17 and 19t cogs are replaced with the supplied 18t hardened steel cog. This creates a cassette progression of 11, 13, 15, 18, 21, 24, 28, 32, 37, 42, 50. The Shark upgrade cog is said to add 80g to the 447g weight of an XT 11-42t cassette.

The Shark Cage increases pulley wheel offset by 50% over a stock Shimano derailleur cage. It’s compatible with Shimano Shadow+ 11spd rear derailleurs (XT and XTR) only. Like the cog itself, the cage is available in grey or grey/green. The Shark cage is claimed to be just 9g heavier than a stock XT cage.

This patented upgrade kit will sell for $125, and don’t forget to factor in the cost of a new (longer) chain.

10t Cluster kit and MiniDriver

Sold as two seperate kits, you can now turn your xt 11-42t cassette in to a massive 10-50t :

You can’t just fit a 10T cog…

Built in collaboration with Hope Technology, OneUp now offers a non-proprietary freehub body that accepts a 10T sprocket – the ‘MiniDriver’. It’s effectively a 4.5mm shorter version of a standard Shimano freehub, and is currently available for Hope, Stan’s and DT hubs, with more expected soon.

SRAM designed the XD-Driver in order to overcome clearance issues of its 10T equipped cassettes. The MiniDriver allows Shimano users to overcome the same limitation, claiming it’ll allow the production of inexpensive 10T-equipped cassettes. ­

The OneUp 10T Cluster kit includes a 10-12t cluster along with 14 and 15t cogs. With the shorter freehub body, this allows the smallest 10t to sit off of freehub body, secured by the larger connecting cogs. Such an upgrade is compatible with both 11-40 and 11-42t Shimano 11-speed mountain bike cassettes, as well as OneUp’d Shimano 11-45 and 11-50 (Shark) cassettes.

By using the 10t Cluster kit, cassette progression is quoted as following:

  • 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)

The 10T Cluster kit sells for $45, with OneUp offering a DT star-ratchet compatible MiniDriver for $40.


So assuming you have a wheel using a MiniDriver compatible freehub design, you’re looking at $210 (plus a new chain) to achieve the full 500% 10-50T range, NOT including the Shimano XT cassette. For us, we suspect the main uptake will be in the Shark 50T cog kit. Either way, the parts can be bought direct from