Grinding noise and sensation on KICKR

Hey guys,

I recently put a new bike on my Wahoo KICKR (a Cervelo with thru axles; previous bike had QR skewers) and noticed that I’m getting a worrisome grinding noise and sensation under certain scenarios. This appears to happen when I’m either in the big chainring and pedaling <80rpm, or in the small chainring and pedaling at any cadence.

Here’s a video: Hopefully you can hear the grinding noise, although it’s a bit quiet in the video.

Have any of you guys experienced this before and have any idea what might be causing it?

For what it’s worth, I checked with Wahoo and they didn’t offer an explanation - they just want me to exchange the entire unit, which I’d rather not do due to environmental reasons if it’s a fix I can perform on my own end.

Thanks so much for any advice!

Maybe is a just combination of new chain and old cassette!

I have not looked at the video yet, but my kicker started grinding last year too. it wound up being a problem inside the drum and I had to send it in period luckily they gave me a new one for warranty for free. if you spin the drum independently without a bike on there does it still make the noise or is it coming from your bike?

I considered this, but didn’t understand why it would only appear at low cadences and more in the small chainring than large!

Sorry, I should’ve mentioned. The sound appears to be coming from the front chainring of my bike, not the machine itself. There’s a grinding sensation when I’m pushing down on the pedals. Strange!

Probably just need to clean or replace your bottom bracket bearings

Re: KICKR - there are known issues with kickr and grinding noises, they have been replacing KICKR18 units due to the keyway issue which was causing grinding sounds under certain load/tensions so don’t discount this as an issue and they will replace.

If its not the KICKR;

  1. check chainline, specifically front mech alignment that chain is not rubbing on front mech guide.
  2. what shape is your front ring/chain in. Are these both new, is one used and one new? are both worn?
  3. Is this grinding less drivetrain and more BB/crankset related?

Got it. I’m riding a refurb 2018 KICKR that I bought in 2019, so I thought they would’ve solved that issue in the refurb process.

The bike itself (including the chain and chainring) are only 2 months old and only have 2k miles on them, so they’re both relatively new (and should have worn at the same rate).

Let me check on the other things you mentioned and get back to you. I haven’t noticed this sound / sensation on the road, so I don’t think it’s the front mech rubbing on anything, but I’ll confirm. Difficult to tell if the grinding is drivetrain or BB related, but let me try to isolate it further and report back.

Appreciate your help with this!