I am a newbie when it comes to bikes and I recently purchased a brand new Cannondale CAAD Optimo Tiagra 2020. After about 3 small rides (no more than 5 km a time), I noticed a very loud creak start to appear. I figured it was just settling noise and maybe needed lubricant in areas etc. But the noise continued to get much much worse as I started using it for my commute (approx 2 weeks at 15 km a day).
I took it in for its 6 week service (at Evans Cycles in London) and was told (to my horror) that I need to return the bike to Cannondale as there is a welding fault in the area north of the front part of the frame that is causing the creak. However, when riding it, I can clearly hear the creak is coming from the crank area and appears to only creak when pedaling, not even when cruising (which you would expect if it was coming from the front of the frame?)
I am really hesitant to return the bike as they said the lead time is 6 weeks and I am not guaranteed the same bike I have bought. Just the next best equivalent. Which in itself seems bonkers. I am using the bike to commute in and out of London so I really don't want to go 6 weeks without it. For cost and obvious health reasons.
I guess my main questions are, fundamentally, is the bike safe to ride? and do you think I should get a second opinion on the source of the noise, problem before admitting defeat and returning the bike to Cannondale for them to check? I have read a lot of forums and it looks like Cannondale have this issue a lot.
Mod note: This question is about a brand new bike frame that creaks, with a frame fault, and an LBS instructing to return it for repair. This question is not about bottom brackets that creak.