Changing the cog on a Cannondale 29er single speed (Formula DC-52 hub)

If like me you have a Cannondale Trail SL 29ER single speed, then at some point you may want to remove the cog that's on the rear wheel. It's really easy to do and even if you're new to working on your bike yourself, so long as you have the right tools, it's something you can do in under 10 minutes.

Generally, for Shimano and Sram cassettes on a mountain bike you'd need a cassette lock-ring tool, a chain whip and then 30 seconds to use them.

Formula DC-52 single speed hub

It's similar for the Formula hub you'll find on the Cannondale, but you need to swap out the traditional lock-ring tool for a lock-ring wrench.

Oh and for those wondering what the hub actually is, it's a Formula DC-52 single speed hub.

Here's what you'll need to remove the lock-ring

• Chain whip
  I use a Park Tools SR-1
• Fixed gear lock-ring wrench (41 - 42 mm)
  I use a Park Tools HCW-17
• Rag and degreaser
  I used kitchen towel and some Muc-Off

5 steps to remove the cog

1. Remove the rear wheel from the bike and also remove the quick release skewer
   
2. Add the chain whip to the cog, so that you can apply pressure to the chain whip and stop the cog from turning on the freewheel
   
3. Place the fixed gear lock-ring wrench (using the 41 - 42 mm end) on the lock-ring
   (be aware that the wrench can slip off in between the lock-ring and the cog if not placed properly on the lock-ring)
   
4. Unscrew the lock-ring counter-clockwise
   
5. Once loosened, the lock-ring can be removed by hand. You should then have
   

Once you've removed the cog, it's recommended to give the cog, lock-ring and the hub free-wheel a good clean up. That's what the kitchen roll and Muc-Off is for.

At the same time, it's worth inspecting all of the parts for damage.

When you come to put it back together

Add a teeny amount of grease to the lock-ring threads. We're talking a teeny tiny amount. Excess grease just attracts dust and debris. The grease (or you can use some anti-lock thread compound) will make it easier to take it apart again in the future.

Also, you won't need the chain whip to put it back together. Simply screw on the lock-ring, clockwise, and then tighten up with the wrench.

Check everything moves as expected and re-fit the skewer (obviously you'll clean and re-grease that too, right. Right?) and put the wheel back in the frame (well, duh).

Hope this helps someone out!