Introduction to Zwift Cog: What is it and how does it work?

Zwift Cog compatibility and adapters: who can install it?

Before discussing keys and gears, we must answer the basic question:
Is the Zwift Cog V2 right for your training base?

1. You already have a Zwift Hub One / Zwift Hub with Cog

Good news: if your base station comes with a Zwift Cog pre-installed, you don't need to add anything .

• The Cog is already mounted on the correct freehub body.
• Virtual gear shifting is natively handled by Zwift (with the supplied controller, the Click or a compatible controller).
• You can focus solely on the maintenance or replacement of the Cog if necessary.

In this case, the Cog + Click adapter kit is only useful if you have an older setup without Click or if you want to add an additional controller.

Zwift Ready Trainers (sold with Zwift Cog & Click included)

These Training bases come pre-installed with a Zwift Cog and a Zwift Click, designed to work with Zwift's virtual shifting. You do not need an upgrade kit.

2. You have a "Zwift Ready / Zwift Cog compatible" training platform

This is a typical case for those who want to upgrade an existing base without buying a new trainer .

• Your base d'formation appears in the official Zwift list of "Zwift Ready and Zwift Cog Compatible Trainers".
• It uses a classic Shimano HG (Hyperglide) freehub body .

You can then:

• Remove your cassette.
• Install Zwift Cog V2 instead.
• Enable virtual gear shifting via the Zwift Click or other compatible controller.

This is the perfect scenario for:

• simplify the exchange of bicycles,
• eliminate derailleur indexing and cassette compatibility issues.

Zwift Cog Compatible Trainers

With the Based on the training bases below, you can install a Zwift Cog and Click Upgrade Kit and enjoy virtual gear shifting (after updating the firmware via the manufacturer's app):

Note: The Zwift Cog is compatible with almost all 8- to 13-speed bikes. It is not compatible with the Campagnolo N3W 13-speed chain.

3. You have a Wahoo KICKR CORE (and special cases)

The KICKR CORE deserves a separate paragraph, as it is often sold in Zwift bundles :

• Some packs include a KICKR CORE “Zwift One” already ready for the Cog.
• Other Zwift kits may arrive with the Cog pre-mounted on a Zwift Hub type freehub body , which is not mechanically compatible with the KICKR CORE.

In this specific case:

• You can't just screw this freehub "Zwift Hub" onto the CORE.
• You only need to transfer the Cog assembly (the pinion + its spacers) onto the original KICKR CORE freewheel body , as explained in the Wahoo documentation.
• If you are not mechanically inclined, now is the time to follow a video tutorial or ask a bike mechanic for help.

Check compatibility before buying

Before even taking out the cassette key, validate these 3 points .

1. “Zwift Ready / Zwift Cog compatible” training bases

The Zwift Cog V2 only works with virtual gears on officially supported models. Otherwise, it behaves like a simple fixed gear, and you lose all the advantages of the solution.

Refer to the Zwift list of "Zwift Ready and Zwift Cog Compatible Trainers" (link at the bottom in the Resources section).

2. Freehub body type: Shimano HG required

The Zwift Cog V2 is designed for a Shimano Hyperglide (HG) body .

Not compatible with:

• Shimano Micro Spline
• SRAM XD / XDR,
• Campagnolo (including some N3W bodies without adaptation).

If your If the training base is on one of these standards, you will either have to change the freehub (if the manufacturer offers an HG body), or give up on the Cog.

3. Bicycle transmission: almost all 8 to 13 speeds

The Cog V2 is designed to work with the vast majority of modern 8 to 13 speed road/gravel drivetrains .

Exceptions to be aware of:

• 1/8 chain (fixed sprocket / single speed) → not compatible.
• Campagnolo N3W 13 speed chain (e.g. Ekar) → not compatible.
• Some SRAM "Flattop" (AXS) chains can slightly accelerate sprocket wear: it's not a deal-breaker, but good to know if you ride hard and often.

Installing Zwift Cog: short version

In most cases, installing the Zwift Cog V2 on a compatible trainer is similar to a simplified cassette change :

1. Remove the current cassette from the training base.
2. Install the Zwift Cog V2 on the Shimano HG body with its spacers.
3. Adjust the chain line (Cog position) to obtain the straightest chain possible.
4. Mount the bike on the trainer, turn the pedals and check that everything turns smoothly, without noise or chain skipping.

Next, we move on to the configuration in Zwift and the activation of virtual speeds .

Detailed installation - "upgrade" mode (replace the cassette)

1. Remove the existing cassette

• Remove the bicycle from the training base.
• Using a cassette wrench and a chain whip :
  • Loosen the lockring.
  • Remove the cassette and any spacers.

2. Install the Zwift Cog V2

• Slide the Zwift Cog V2 onto the HG freehub body.
• Add the spacers provided if necessary (depending on the required thickness).
• Screw and tighten the lockring as you would for a standard cassette.

3. Adjust the chain line

The Cog V2 offers several possible positions on the freehub.

• The goal: to obtain the straightest possible chain between the front chainring and the Cog.
• A good chain line = less noise , less friction and less wear .

You can try different positions by:

• mounting the bicycle,
• by turning the pedals,
• by listening and observing the alignment.

4. Special case: Wahoo KICKR CORE

If your kit arrives with the Cog already mounted on a "Zwift Hub" type cassette body , be aware:

• This freehub is not compatible with the KICKR CORE.
• You should not try to mount it as is on the CORE (risk of damaging the trainer).
• It's necessary :
  • Remove the Cog assembly from the Zwift Hub freehub,
  • reattach it to the original CORE freehub (Shimano HG),
  • Follow the step-by-step procedure described in the Wahoo documentation (link in Resources ).

Enable virtual gear shifting (Zwift Click)

Once the Cog is in place and the bike is assembled:

1. Attach the Zwift Click to the handlebar in the most natural location for you (near the brake levers, the top of the handlebar, etc.).
2. Update your firmware training base via the manufacturer's application: this is often essential to activate Virtual Shifting .
3. In Zwift :
   • Pair your training base.
   • Pair the Zwift Click (or other compatible controller).
   • Check that the "Virtual Shifting" option is available and enabled in the settings, according to your setup.

Do a short test ride in Zwift (on a flat course) to check that:

• Virtual speed changes are correctly taken into account.
• the resistance varies correctly.

Common mistakes to avoid

A small box that will prevent many disappointments:

Buying a Cog kit without checking its compatibility training base

Always check the official Zwift list before purchasing. An unsupported trainer = no virtual speeds .

To assume that the kit's freehub is compatible with all trainers

The freehub body supplied with some kits is designed for the Zwift Hub , not for all models on the market. For example, it should never be installed as is on a KICKR CORE.

Forget the calibration/update

• No firmware update = sometimes no Virtual Shifting.
• No calibration (spindown) = distorted sensations, inconsistent resistance.

Ignore the string line

Installing the Cog haphazardly can cause noise, friction, and premature wear . Take a few minutes to adjust the position and ensure the chain is as straight as possible.

Useful resources to go further

To secure your installation and check compatibility, here are some links to keep handy:

• Zwift Cog adapter: For Garmin-Tacx base , for Elite base , for Wahoo, Van Rysel or Jetblack base
  
• Zwift support article: Zwift Ready and Zwift Cog Compatible Trainers
  Up-to-date list of Zwift Ready and Zwift Cog Compatible training bases, with all compatibility notes.
• Wahoo Support - Zwift Cog: Removal / Replacement / Installation
  Step-by-step tutorial, especially useful for Wahoo KICKR CORE users.
• Video tutorial - Installing Zwift Cog on multiple trainers
  Video (in English) that visually shows the assembly steps and the differences between models.