I had an issue this morning with my new Kickr'18. I think I've sorted it. I began to get a clunky noise as if the BB was going to fail. after I finished my workout I began tracing the noise. I eliminated the crank by pedalling single footed, to see if it was on either side of BB, noise still present with either foot. I removed bike from Kickr and when turning I could hear a knock from the mechanism. I removed the side cowling to reveal the pulley's. Grabbing the large belt pulley and pulling it followed by an abrupt stop I could make the clunk noise. I traced it the bottom pulley with a Allen bolt holding the pulley in place. It was only finger tight. I removed it to see a little metal powder(it had been moving/rubbing) .The washer on the bolt is/has become cupped due to pressure. it's not a good design and really needs a spring washer under a thicker outer washer to apply pressure to the Woodruff key, which keeps the pulley snug on the shaft. I've applied more thread lock, because there was nt enough in my opinion and tightened up more than finger tight
View attachment 432526
View attachment 432527
. Everything is now quiet again
see here new pulley and belt design (ribbed not tooth belt) for silent running. tensioner is almost identical to earlier Kickr design- beefed up design.