What is this noise
 

Hi all,

Since a few days my back wheel makes this noise and slows down really fast when spinning.
can anyone identify what it is? Do the bearings need replacement or is it another (hub?) Problem?

https://youtube.com/shorts/T3F2xBZ6aIM?feature=share

The wheels are 3 years old and have some 10k+ kms so I would not surprised if the bearings are worn out.
These are the stock cannondale topstone apex 1 2019 wheels. How do I know what bearings I need?

Best regards

I would grease or over haul it first and if you have neither the skills, the tools or parts a bike shop is your friend. Roger

yup will do that next Saturday, was just wondering if anyone knows what might be the problem :) thanks

It doesn't really sound like a bearing issue to me; however you may just want to overhaul them anyway. Typically you would gauge bearing issues by turning the axle by hand to easily feel imperfections.

My wild guess about the noise is that it's coming from the cassette 'catching up' with the momentum of the rim, which spins faster initially. As the cassette catches up, a pawl may click into the next position making this click. This would be normal and of no concern.

Try spinning it the correct direction

makes no difference.i removed the casette to check but with casette removed the same issue remains...

Quick release springs catching as you spin it ?

the bike has 12mm thru axles...
if not the bearings i fear the cost of repair. I can really feel the 'clicking' in the hub axis
Fingers crossed :(

Got my bearings replaced, problem solved!