Cassette Compatibility & Kickr Core Grinding Noise?

Hi all,

New to cycling and indoor training here!

Just got a Wahoo Kickr Core and was wondering if the Ultegra CS6700 10 speed - 11x28 is compatible with my bike: https://www.specialized.com/us/en/tarmac-sl6/p/175300?color=293448-175300&searchText=90621-7044. I know my bike’s cassette is Tiagra 10 speed.

The reason I ask is because on my Kickr Core the drivetrain makes a slight grinding noise (I can even feel it a bit as I hit the bottom of my stroke). It’s more obvious the harder the gear. Not sure if this is normal with new cassettes (I’m using the Ultegra) or if I’m misaligning something?

Would appreciate any help! Thanks :slight_smile:

What is the tallest gear of the Tiagra? Also what derailleur are you using? Shouldn’t have an issue. I’m using an 11x28 with a short cage derailleur and it’s ok. Sounds like a potential misalignment somewhere

The Tiagra cassette on my bike has 32 for the largest gear in the back.
The rear derailleur is Shimano Tiagra, 10-speed.

I’ve never used two different sized cassettes. You might be slightly off on the index since you’re going from a 32 to 28. Maybe someone else can comment if that’s potentially the issue. It would be pretty inconvenient to re index every time you swap from trainer to wheel.

I would suggest indexing the gears for the 28 if you haven’t already and see if that gets rid of the grinding

The Core uses an 11 speed free hub. Did you install the spacer needed for 10 speeds?

How old is your chain?

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:point_up:Get yourself a decent metal ruler and learn how to check your drive train for wear. It’ll save you from destroying a new cassette (if that’s the cause of the grinding).

I own a few bikes and often swap bikes on the trainer without changing the cassette over. Provided your staying in the tooth range that the chain and derailer is set for you shouldn’t have an issue with chain length/derailer travel.

Just be aware that the chains get narrower as you add gears to the cassette. The length of the links stays the same, but a 10 speed chain won’t fit a 12 speed cassette for example.

make sure the bike is fully seated in the dropouts and not overly tight.