• BLACK by Absoluteblack Expander Sprocket

        • $48.99 48.99
        • RRP $67.50
        • Save 27%
    • Select Colour
      Select Option
      Select Teeth

BLACK by absoluteBLACK Expander Sprocket

Great solution for Shimano cassette users who require that one extra sprocket on steep climbs. Very simple to install, it fits behind 11-36 cassettes, displacing one sprocket from the main cluster.


  • 40T Expander Sprocket allows you to upgrade your existing 11-36 10spd cassette to give an 11-40T range
  • The most advanced shifting ramps and teeth profiling on the market play with great harmony with rest of the Shimano cassette
  • 16 upshift and 24 downshift points. Shifting is crisp and extremely quick
  • Installing the cog is easy. Remove the 17t cog from your cassette, place the 40T cog on your freehub, and then install your existing cassette back in place
  • Designed in UK, manufactured in Poland
  • 7075 Txxx Aluminum. Long-lasting construction!
  • Weight: 78g


  • Compatible with Shimano XT (CS-M771-10 11-36) and XTR (M980 11-36)
  • Compatible with Shimano SLX (CS-HG81 11-36) by removing 11t and use of special 13t lockring available from absoluteBlack
  • Compatible with 1x10 and 2x10 drivetrains

There are two ways to fit 40T sprocket to your drivetrain. You can remove the stock 17T sprocket and one spacer from your cassette, then put 40T on the freehub and mount everything else back (except 17T). OR, by removing 11T sprocket.

If you don't know which option would be better for you, then just go for a ride and observe which of these two sprockets (11 & 17) you will miss less.

For running a 1X system, please use medium cage rear derailleur. When in use with 2x10, most recommended is long cage.

Other products available from BLACK by absoluteBLACK

Buy BLACK by absoluteBLACK Components from Chain Reaction Cycles, the World’s Largest Online Bike Store.

  • Delivery cost $9.99
  • Delivery toUnited States of America
  • 365 Days return or exchange

    If you're not completely satisfied with an item you may return it within 12 months of purchase. We'll give you a full refund if the item hasn't been used or the component hasn’t been fitted.

    More information on returns
  • Pay by Bank Transfer, PayPal or Card


  • Colour: Black
  • Option: Shimano
  • Teeth: 40t
  • Speed: 10 Speed

Interested in BLACK by Absoluteblack Cassettes?

Cassettes Buying Guide

  • We've got everything you need to know in our buying guide.

Also Consider...

Also Recommended...