Changing Tacx Neo & Tacx Flux cassettes


If you own a Tacx direct drive trainer or you are thinking about buying one, your first worry will be about the cassette. The concept of direct drive trainers is to remove the wheel off before putting your bike on the trainer. This means your trainer will have to include a cassette. People generally wonder which cassette they need, if it is included in the box or not, and how to mount and dismount a cassette on your trainer.

Let’s make sure you are ready to train for the winter months (and more when you’ll get addicted to it :p)! Let’s dig into the world of cassettes and see what’s best for your Tacx trainer and how to change it. Don’t worry I will talk about the different Tacx direct drive trainers: Tacx Neo series (Tacx Neo, Tacx Neo 2 and Tacx Neo 2T) and Tacx Flux (Tacx Flux, Tacx Flux 2, Tacx Flux S).

As a general comment, I will refer to Tacx Neo and Tacx Flux in the article for any of the Tacx Neo and Tacx Flux trainers. I will only specify the exact model if there is a difference to know about.

Does Tacx Neo series come with a cassette?

Tacx Neo turbo trainers do not come with a cassette. You will have to buy it separately. Tacx Neo, Tacx Neo 2, and Tacx Neo 2T all come with a freehub compatible with 8-11 speed Shimano / SRAM cassettes.

Does Tacx Flux series come with a cassette?

Tacx Flux turbo trainers do not come with a cassette. You will have to buy it separately. Tacx Flux, Tacx Flux 2, and Tacx Flux S all come with a freehub compatible with 8-11 speed Shimano / SRAM cassettes.

What cassette do you need for Tacx Flux or Tacx Neo?

You need a cassette compatible with your bike derailleur for your Tacx Flux or Tacx Neo trainer. It is recommended to use the same cassette as your bike on your trainer. This will provide you with the same gearing ratios and sensations you are used to when riding outdoors.

The best option is to buy the same cassette for your trainer as on your bike. Not just the brand but also the same gear range. Why?

  • Same gear ratios => same feeling in your legs
  • Best shifting performance
  • Compatible with the rest of your drivetrain:
    • no need to re-index your gears each time you hop on the Kickr
    • no need to worry if the chain length is ok
    • no risk of over-stretching the chain
It is best to buy the same cassette as your bike

How to be sure which cassette is mounted on your bike?

If you are unsure about the cassette on your bike, let me guide you to find out what you have and help you buy a new one. Knowing the cassette on your bike is also important if you wish to change it, or get a new cassette in the future. So let’s see how to know which cassette you have:

1. Let’s check the brand & model

The brand of your cassette is written on the lock ring near the smallest gear (see picture below).

Where to read the brand of your cassette

The model is written next to the brand name. In the example above, the model is ‘105’.

2. Let’s check the number of gears

You will also need to verify the number of gears on your cassette. This means counting the number of speeds you have (just count the number of cogs on the cassette). In the example above it is an 11-speed cassette.

3. Let’s check the gear range

Now let’s check the gear range of your cassette. You can either:

  • count the teeth on the small gear and on the biggest gear
  • look for the number stamped on the cogs (small and big cog)

Nowadays on a road bike, a common gear range on a cassette is “11-32”, where “11” is the number of teeth on the smallest cog and “32” the number of teeth on the largest cog.

So the cassette in the photo above is a Shimano 105 11-speed 11-28.

Is your cassette compatible with Tacx freehub body?

Tacx Neo and Tacx Flux turbo trainers come with a freehub body compatible with 8-11 speed Shimano / SRAM cassettes. You can buy separately Tacx freehub bodies compatible with Campagnolo, SRAM XD and XD-R body but not for specialized SCS system. Make sure to pick the right axle type for your trainer.

If you need to buy a different freehub body from the one provided with your Tacx trainer, you will have to be careful. Tacx sells two types of freehub bodies per model. This is what they call Type 1 and Type 2. It depends on the axle internal diameter. It is very important to buy the correct one for your trainer.

How to know which type of axle your Tacx trainer has?

Have a look at the freehub body installed on your Tacx trainer. Attention, you need to remove the cassette to see the difference (if you already have one mounted on your trainer).

Then read the writing on the freehub, if you see:

  • T2805.01 (S) then it is a Type 1
  • T2875-01 then it is a Type 2
On my trainer, I have a ‘T2805.01 (S)’ freehub body, meaning it’s a type 1

Which freehub body to buy for your Tacx trainer?

If your cassette is not a Shimano or SRAM 8 to 11 speed, then you will need to buy a new freehub for it to work with your Tacx trainer. Use the table below to find which model you need.

CassetteFreehub body
TYPE 1
Freehub body
TYPE 2
Shimano / SRAM (*)S0012S0050
CampagnoloT2805.51T2875.51
SRAM XD-RT2805.81T2875.76
SHIMANO micro spline cassette
(11 & 12-speed XTR cassettes)
N/A010-13042-07
Tacx Freehub body guide

*This is the freehub body provided with all Tacx trainers by default. It is included in the trainer’s box.

Can you use a cassette with a different gear range from your bike on your Tacx?

It is possible to use a cassette with a different gear range from your bike on your Tacx Flux or Neo trainer. You need to make sure it is compatible with your bike’s drivetrain. And you need to check the chain length is ok with the new cassette, as well as the gear indexation.

One reason to have a second cassette with different gear ratios could be to have the possibility to switch it with the one on your outdoor bike from time to time. For instance, using a classic “11-28” on your bike and having an “11-32” on your trainer as a backup cassette for your next trip to the mountains.

If you are using the same bike indoor and outdoor, be careful if you are using different cassettes that the chain will be at the right length and not overstretched by the change. You’ll probably have to consider having a second chain with a quick link to change it from time to time. This is not very practical to do. I would not recommend it.

If you want a different cassette, it is best to have a bike dedicated for your indoor training and one for your outdoor rides.

Which cassettes are compatible with Tacx Neo & Tacx Flux?

Straight from the box, your Tacx is compatible with a wide range of Shimano / SRAM cassettes. See the details in the table below.

Trainer8-speed9-speed10-speed11-speed12-speed
Tacx Fluxxxxx
Tacx Flux 2xxxx
Tacx Flux Sxxxxx(1)
Tacx Neoxxxx
Tacx Neo 2xxxx x(1)
Tacx Neo 2Txxxx x(1)
Cassette compatibility with Tacx trainers on the default Shimano / SRAM freehub body

(1) According to the manual though not specified on website specifications.

Would a 8, 9 or 10-speed cassette work on Tacx Neo or Flux?

A 8, 9, or 10-speed cassette will work on Tacx Neo and Tacx Flux trainers. You will have to install the 1mm spacer provided in the box. If your cassette also includes a spacer, you will have to add this additional spacer to the 1mm spacer. Same with other freehub bodies.

How to mount a 8, 9 or 10-speed cassette on your Tacx Neo or Tacx Flux

Would a 12-speed cassette work on Tacx Neo or Flux?

Tacx Flux 2, Tacx Flux S et Tacx Neo 2T are directly compatible with Shimano 12-speed cassettes. Older models are not compatible with them. Campagnol & SRAM XD-R bodies are also compatible with 12-speed cassettes.

How to mount a 12-speed cassette on your Tacx Neo or Tacx Flux 2 and Tacx Flux S

How to change Tacx Neo and Tacx Flux cassette?

Assuming your cassette is a Shimano / SRAM cassette. You will need a lock ring tool and a chain whip to change your cassette.

Tools to change your cassette

Now just follow the steps below to first remove your cassette and then mount a new cassette on Tacx. The process is identical on Tacx Flux series of trainers and Tacx Neo trainers. I will demonstrate it on my Tacx Neo.

Steps to change a cassette on a Tacx trainer:

1. Remove your bike from the Tacx trainer

2. Remove the quick-release skewer from the Tacx trainer

Removing the quick-release skewer from your Tacx trainer

3. Engage the lock ring tool into the splines & notches of the cassette

Engaging the lock ring tool in the cassette

4. Hold the biggest cog in the clock-wise direction with the chain whip tool

To untighten the cassette you will have to turn the lock ring tool anti-clockwise. Therefore you need to place the chain whip to prevent the cassette from rotating while you are turning the other tool. See the picture below.

Place the chain whip on the biggest cog

5. Turn the lock ring tool in the anti clock-wise direction to untighten the cassette

Untightening the lock ring

6. Once it is turning freely, keep unscrewing the locking ring until you can remove it

Removing the lock ring

7. Slide the cassette off the freehub body

8. Locate the largest gap on the freehub of the Tacx trainer

The freehub body has a number of notches on it. There is one wider gape on the freehub body that you need to locate.

On the Tacx freehub body, the largest gap is the one with the writing. Easy to find 🙂

9. Locate the largest gap on the cassette

Locate the widest spline on the rear of the cogs of the cassette to be able to align it with the widest notch on the freehub body.

10. Place the 1.8mm spacer if you are riding a 10-speed cassette or less.

If your cassette already comes with a specific spacer, don’t forget to add it after the 1.8mm spacer.

11. Align the cassette with the largest gap on the freehub body and slide it on it.

12. Do it for all the cogs (the smallest ones are generally separated from the big ones)

13. Now you can add the locking ring and tighten it manually

14. Insert the lock ring tool

Inserting the lock ring tool to tighten the lock ring (clockwise screwing)

15. Place the chain whip on the biggest cog to prevent the cassette from turning

Place the chain whip the other way around to block the cassette from rotating

16. Tighten the lock ring with the tool until you no longer hear a clicking sound

17. Put the quick-release skewer back in place

Cassette setup and ready to use!

Things you need with your smart tra...
Things you need with your smart trainer

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