Just bought a new Corratec CCT Evo and there has been an annoying noise from the crank. It's a rubbing noise that is always present when pedaling at any cadence or power.
Listen here: https://streamable.com/gnq4br
The noise seems like it's coming from the chainring side of the crank.
The LBS where I purchased the bike said that the bearings need time to break in but that sounds strange to me.
Any thoughts?
The clear video and audio are helpful, although it’s not clear to me what’s wrong. The amount of friction you get when spinning the crank seems normal. The noise is definitely not normal. It sounds a little like the sound a bearing might make if it’s dry, I.e. all the grease got washed out, or it was somehow not greased in the first place. It doesn’t sound exactly like that, however, and you also don’t expect that on a new bike. You could remove the crankset and try turning the bearings on each side by hand. This might localize the issue. It’s hard to describe, but see, feel, and hear if the bearing turns normally without roughness or a scraping sound.
When people talk about cartridge bearings breaking in, they may be referring to the rubber seals breaking in. That can happen, especially as you distribute grease over the lip of the seal. That will reduce the friction you feel as you spin the crank by hand. I don’t know that the actual bearings and races exhibit a significant break in effect. They might polish off initial surface roughness, which is thought to happen with new bike chains. That would decrease the resistance at full load, when you’re pedaling with your legs. Neither break in process explains a whirring noise. Something is significantly wrong somewhere. I am a bit put off by the bike store's response. A reasonable mechanic would know that something is off.
I was able to get the crank arms and axle out and found that one of the internally routed cables in the frame came off the guide at the bottom of the bike... This cable was rubbing heavily against the axle making the noise and cutting a nice groove into it... I wonder what would have failed first, the axle or the cable...
Thank you @weiwenng for the help and encouragement to get my hands dirty!
