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e*thirteen EX Cog Cassette Range Extender
inc. VAT
  • Add-on cog to extend gear range of 10 spd. Shimano and SRAM cassettes
  • Timed and ramped specific to Shimano and SRAM cassettes



1x Drivechains are everywhere you look this season from complete bikes to winning enduro rigs. Everyone is doing it so why should you have to miss out? With the e*13 EX Cog range extender you don't have to. Simply fit this sprocket to your existing 10 spd cassette, using the clear instructions provided, and say goodbye to your front shift setup.

  • It's an add-on cog to extend gear range of 10 spd. Shimano and SRAM cassettes
  • It comes in 40t and 42t for use with Shimano cassettes and a 42t only for use with SRAM cassettes
  • Installing your EX Cog is easy. Remove the 15t or 17t cog from your cassette & place the EX Cog on your freehub, then install your existing cassette back in place (complete instructions here)
  • Each EX Cog is timed and ramped specific to Shimano and SRAM cassettes
  • The EX Cog comes with a longer steel replacement, B-limit screw for your derailleurs. Your current one won't be long enough to get the best shifting up to the new cog
  • Available in Black, Red, and Blue

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EX Cog compatibility chart

Click below to download

Extended-Range-Cog-Compatibility_D.pdf (1 MB)

Can I use the 40 tooth (40t) EX Cog on my 36 tooth cassette?

We don't recommend using the 40 tooth (40t) EX Cog with a 36 tooth cassette. Shift performance will be compromised as the timing of the shift features relative to the cassette will not be correct.

Can I use the 42 tooth (42t) EX Cog with a 34 tooth cassette?

The 42 tooth (42t) EX Cogs WILL NOT work with 34 tooth (max) cassettes. A 6 tooth jump is the maximum for excellent shift performance.

Is it hard to set-up the EX cog?

It's really not too hard, but keep in mind that you are working at the extreme limits of your rear derailleur, so small changes can make a big difference.

If you are still struggling with the setup and adjustment, we recommend heading to your local bike shop.

I have a really worn drivetrain. Will the EX Cog work ok on my bike?

Old drivetrain components could cause poor shifting performance. We recommend a new chain and a new or well-cared for cassette.

What is the extra screw included with the EX Cog for?

It's a replacement B limit screw for your rear derailleur. The longer screw may be needed for proper derailleur set-up. If you are unsure about setting your B limit, refer to our how to guide, or head to your local bike shop.

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