I upgraded a full groupset, including the crankset on my Trek Madone. My particular Madone uses Trek's press-fit BB-90 internal bottom bracket. I probably had 15,000 miles on the BB when I changed out the crankset. I've got about 1,000 miles on the new crankset and I'm hearing (and feeling) a deep "popping" or "knocking" sound coming from the BB/crank area, which has started within the last few hundred miles.

Here's what I've tried so far to try and isolate it:

-Remove and replace pedals
-Inspect and tighten rear QR
-Lube spoke crossover points in rear wheel
-Check torque spec and lube chainring bolts and crankarm bolts
-Check BB press fit for looseness by wiggling crankarms
-Clean and repack BB bearings with grease
-Inspect BB shell in bike for wear/cracks/looseness
-Regrease Hollowtech II BB spindle, and splines where left crankarm attaches
-Inspect crankset
-Re-install old crankset

None of this has done anything to help. It happens most frequently under load, and *seems* to occur more on the small chainring/larger cogs combo (though not just one gear). Since it does happen (less frequently) in the big ring, I can't see how it could be a chainring bolt issue. Like I said, I tried re-installing the old crankset, and it still seemed to happen, but not as much, so I am guessing this eliminates anything to do with the new crankset itself.

Here's my theory, tell me how much I'm an idiot if necessary

I wonder if, through 15k miles on one BB/crankset combo, that these parts wore evenly. Perhaps now there is *the slightest* discrepancy in the diameter of the bearing races and the new BB spindle, which is "popping" as I put load on the crank and the parts slip within the BB shell. The next thing I want to try is to replace the BB90 (not very costly), but I don't know if that would void the Trek warranty. I don't want this to be a cracked frame issue that's just now starting, which could get worse (if it is, and I void the warranty, I'm SOL). It's a white bike, so I can use a flashlight to illuminate the frame, and I don't see any hairline cracks. But obviously I'm not an expert at this, I may not be able to see, or determine what cracks could mean what.

Is it worth a try to replace the BB90 with the new crankset, or could it be something else? Thanks!!

do your new bearings slip in easy or are they tight. over time the frames bore tends to get oversized. trek does offer an oversized bearing i believe .1mm larger

I haven't been able to pull the bearings out. They are still pressed in very tight. I'm aware of the slightly oversized bearings needed on some models, but I am highly doubtful that is the issue. I had gone 15k miles on a previous drivetrain that never had any issues with the BB. I'm more concerned about the wearing out of the inner bearing race from the previous crankset.

i would move away from the crank and bb area. look elsewhere. try the rear wheel or derailer hanger and frame interface

The bearings are $20 and can be worn to the point where they need replacing in as little as 3-5k or so. I don't know why it wasn't suggested you replace them at the same time you did the new crank; if you did the replacement on your own, replace the bb bearings. Even if you like to work on your own bike and are competent doing your own work, this is a great time to have a shop do the install -- they should have the correct install tools, and they may be able to suggest something else where the noise is concerned.

Other than that, I would also check the screws holding your cleats to your shoes, the seatpost/-mast clamp (to indicated torque setting), and the saddle rail clamp (to indicated torque setting).

I have a hard time believing it could be anything to do with the frame itself, and replacing the BB even on your own shouldn't void the warranty.

There was a very recent thread in the road forum about BB30/PF30/BB90, etc. The consensus seems to be that if you are hearing noises from your integrated BB, the cure is Loctite 609 on the outer diameter of the bearings. I'm not sure why they started making the noise after installing the new crankset, but perhaps you disturbed something about the fit when you removed them (or did you not ever remove them?).

As far as worrying about voiding your frame warranty, that you've done any work on the bike yourself (or did a Trek shop do the work?) could potentially void your warranty, but I would hope not. Regardless, I think it's very unlikely that you have a frame issue and far more likely that you have a case of slightly loose crank bearings that need help staying put.

Excellent reply, I will do it. For sure I will have a shop do it, from what I read, you need to install the press fit BB with a special tool. I don't even know how to pull them out! Like you say, they are $20, even if it's not that, it's probably good to replace. Had it been a traditional BB, I would have replaced it anyway with the new groupset.

Everything is new in the groupset, so I suppose one of these other areas could be the issue. From what I seem to be experiencing, I can swear it's coming from the BB area. (Though I've heard noises that I thought were from that area, and turned out to be the front QR, or in the rear cassette...so who knows!)

Replace the bearings. 15,000 miles with no service is a reasonable amount of life for a set of radial bearings. On the Park tool site they recommend periodic maintenance on radial bearings.