Hi all, first time poster. A shout out to Wahoo for bringing me to this site. So I stopped by the LBS to demo a Kickr on display. Rode it for a bit on zwift and was really impressed with how quiet it was. The smoothness was so nice, light years ahead of my old fluid trainer. I ended up purchasing a couple of Cores from them (they had a slight discount , how could I refuse!) for the missus and myself.
I took the first one out of the box and lets just say I was less than thrilled with the QC at wahoo. It was nothing like the machine I demo'd. Just spinning the flywheel by hand resulted in this annoying, grating sound. Closer inspection revealed the belt was rubbing on the cover. You could gently flex the cover and it would fix the issue but it would just return and continue to rub. Being the tinkerer I am, off came the belt cover and a small square of haevy poster paper was added between the frame and cover. It was the perfect spacer to have the cover clear the belt. Its a half arse fix but whatever, no one can see it and only I know it's there.
That's when I noticed the belt was tightened to banjo string tight. It seemed completely unnecessary for the belt to be that tight being that we're just puny humans with puny human strength. A little google searching about Wahoo Core issues and here I am. There is a whole wealth of good info here for sure. I ended up taking everything apart. I pulled off the flywheel off so I could check that there were no issues with the bearings, both spun smooth with my fingers with no roughness. There was debris on the electromagnets and inside of the flywheel that I cleaned up. Looks like I have the old style bolt and key as well. Oh, and I know they're very close in size but I'm pretty sure it's a 14mm, not 9/16 bolt. Just for fun I left the bolt finger tight and it knocks like a champ when the pulley is spun. I tightened the bolt to about 8 ft/lbs with some blue locktite and I used a 2mm allen to tighten the set screw on the flywheel pulley which wasn't even tightened to begin with. My guess is tightening the set screw locks the pulley to the key and prevents it from moving.
After all that, the Core is mostly silent at speed. I spun it up in the 53-11 to what I would say is 35 mph and there is some whining noise but it's mostly obscured by the freewheel noise. The balance isn't perfect but I guess it's not too bad. At ludicrous speeds there's some slight buzzing in the seat but at 20-25mph it's minimal. Another noise that I would notice at speeds was this frump, frump, frump sound that seemed to follow the diameter of the pulley. After searching around, I believe the noise comes from the ever so slight raises on the back off the belt where it's fused when it rolls across the idler pulley. The sound pretty much goes away when you take all the tension off the belt.
So after all that with the first Kickr, I unbox the second one. It's just about perfect. No rubbing belt, no clunks, no whirring noises, bolts tight, and the belt was what I would say to be properly tensioned. Really makes me question the disparity of QC of the two machines. I have to laugh at what I read above about "properly tensioned belt" from the factory. I'm just a backyard hack when it comes to mechanics but simply plucking the belts tells you that in no way were those belts even remotely close in tension.
hope this one has no problems
