New Kickr Core, super noisy drive train, grinding feeling?

So I just got my first direct drive trainer a Kickr Core. I put my Trek Domane SL6 Disc on it and when I spin the crank it feels awful. It sounds like there’s a grinding coming through my bottom bracket and rear cassette. I have the same cassette as my rear wheel (Ultegra 11-32t) and I guessed everything would just transfer over and be smooth, like riding on the road. Any ideas of what’s going on?

I’ve tried changing the cable tension, looser or tighter effects the shifting but not the grinding or slight click (maybe 2-3 per crank rotation). I’ve looked at the hanger and it looks straight, never had an issue with it on the road. I’ve got the TA adapters in for the 12x142 size.

In the box with the teainer there was a silver thin spacer, but I didn’t use it, is that something I should have? The instructions were not all that clear.

Suggestions? I shouldn’t have to adjust when going from trainer to road with a direct drive trainer should I?

If the indexing is right, and derailleur + hanger are straight, the grinding could be from the cassette having a different wear pattern that the chain i.e. new cassette, worn chain. Worth checking the wear on your chain with a gauge to see if this could be it.
Also, its not uncommon to have to tweak the indexing when moving from trainer to wheel, and vice-versa.


I think that @DaveWh is right on this. Did you ever try and put the old cassette on the trainer? My ALR5 Disc goes on the CORE like a champ. I also did not use the silver spacer. Just the two adapters for 12x142.

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I wouldn’t have thought that it would be worn yet, there’s probably only 1000 miles on the bike. I’ll give it a shot though!

I’ll swap cassettes and see if that’s it!

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I upgraded my original model Kickr into a Kickr Core. The first one they sent me had a major grinding noise in the trainer itself. Unfortunately for me I went as far as building it up and putting my bike on it before I noticed the noise.

You didn’t explicitly state that you tried this step - so if you haven’t - take the bike off and just spin the fly wheel by hand - see if you get the same noise. Make 100% sure where the actual noise is coming from

Yours is likely something totally different than mine - but it is worth checking whether the actual source of the noise is the trainer or your bike’s rear mech.

As a short follow-up Wahoo was on top of a replacement for free, so I was only out of pocket for a drive to FedEx to drop off the busted one plus the delay in arrival of a new toy. Good customer service experience

I had this same issue with a New Wahoo Kickr 2018. It is a known problem in this model but I am not sure about the core. I would take a video when it happens and create a ticket. You will more than likely get a replacement.

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I was kind of afraid of that. When I turn the flywheel it does make a slight metal on metal scratching sound, a bit worse than a disc brake rub. I forgot to mention that.

It’s the trainer. Record a video of the noise with the bike off the trainer and submit a ticket to Wahoo they’ll ship you a replacement and give you a shipping label to return yours

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What is the known issue? Manufacturing defect? Hopefully they sort it, nothing like paying full retail for something, going through the hassle of boxing up what is a heavy item, waiting, then receiving a refurbished replacement. I like the Kickr, but I wouldn’t call the experience “good customer service” if it’s a known issue.

I have no idea if it’s a known issue - I was only relating my personal experience with them. If it is more widespread then it is likely a manufacturing problem.

I got my new one in the mail late last week and it has no apparent problems, but I haven’t ridden it yet - certainly would change my opinion if they sent me multiple ones with the same issue

First thing i’d check would be the chain/casette as above. I had it before when i put on a new chain, was grinding horrifically when pedalling. Was silent when i used the old casette/chain combo.

Almost certainly not your problem but I’ll tell my story. Bought a 2017 Kickr a year ago, because it had the new adapter for disc brakes. Tried mounting my 2015 Trek Domane 6.2 Disc (post mount) and the reversible adapter didn’t have enough clearance. By muscling the bike I could get it on the Kickr, but it was obvious something was wrong. After discussing with Wahoo support, sending pics, waiting for them to locate similar bike, etc., about 4 weeks later they delivered a new adapter. The solution - machining down one side of the 2017 adapter to provide additional clearance for Trek models with the post mounted disc brakes.

+1 for new cassette on old chain (not worn out chain, just older). Check that first before creating a support ticket with wahoo, by putting the cassette from your wheel onto the trainer…

Reviving this thread - I think I have this exact problem. Just bought the Tacx Neo 2T, have a grinding noise and have landed on this thread. :slight_smile:

I will check tomorrow if it is resolved by using the old cassette, but then the problem is: This can’t be a sustainable solution if you have only 1 bike that you use outdoors too. Changing the cassette every time doesn’t seem to be very appealing…

Would the grinding noise eventually go away if I just kept the new cassette on it, or would it just ruin my chain?

But this thread is specifically about the Wahoo Kickr Core.
What does that have to do with your Tacx Neo 2T?

I’d expect to look at the existing threads on that trainer for relevance to you trainer.

The difference between these trainers is massive, and the only thing common is your own bike.

Apologies, but the description of the problem and the suggested resolution seemed to me quite the same, irrespective of the brand of the trainer. It is suggested that it is old chain on new cassette that causes this.
To avoid any confusion, I will reopen a new thread then.
– edit – and yes, I did do a search before.


Tricky, I know. But when people start researching problems with Trainer X, and the solution is not trainer related, it is a tough choice to make. You can keep it here, I just wanted to point out the potential confusion.

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Switching to the old cassette solved it for me. Thanks guys.

Not for me though. I had to return the product.

However, today a local shop guy told me that it could be the derailleur…which in my head makes sense.