Nbob

I noticed some BB creak the other day so I got off the bike and this is what I saw:
It looks like the paint/finish has been sheered off right down to the BB sleeve ( there's more on the underside ) I can think of a couple of things-

1. When the guy at the LBS did the 1st month tune up he tightened the adapter too tight and sheered some of the finish ?

2. He didn't tighten the adapter enough and by putting force on it I've sheered it and knocked it out of alignment ( it looks like it might be too far back and up by a mm or two maybe ? ) ?

3. It's missing an O ring that goes between the adaptor and the frame ?

Anyone else seen this ? Anyone have any other ideas about cause or fix ?

531Aussie

Hmmm, that's a tricky photo with the reflection of the BB in the frame -- I didn't know what I was looking at at first.

I'm not sure what you mean by 'adaptor' -- do you mean the bb cups (even though they're not really 'cups' anymore, in the traditional sense)?

Here's my shot at it:

It's not uncommon at all for paint to be ripped off that area when the BB cups go in, because most frames aren't faced and finished properly, and while there may be no paint on the threads inside the frame, there's often a whole hunk of thick paint left on the outer edge of the BB shell. Because the cups go in so tight, they grab this paint and tear it off, usually taking off a bit extra, as yours has. I have one that's much worse than that, and I just went over it with touch-up paint, because I wasn't too fussed

Other than that, assuming the guy has done up the BB tight enough, it's probably not the cause of the creak. Also, if any creaking comes from the BB, it's usually (but not always) from the right side, due to the higher drive-side loads

Apart from the bottom bracket, creaking can be caused by a lot of things (and it might not even be coming from that area): worn pedals, loose cranks, the threaded alu insert creaking in the frame, the joins between the carbon stays and the rear drop-outs, etc...

Nbob

Thanks 531Aussie - both helpful and reassuring

sorry 'bout the photo, the finish is so shinny I couldn't get a shot without reflection - makes chips/flakes all the more noticeable and upsetting.

I don't know what to call the "cups" anymore either, the wrench who taught me repairs called them something like " out board bearing rings". Shimano's specs call them "adapter" - for which, of course, you need a proprietary " Adapter Installation Tool" to instal. Anyway....

I've been troubleshooting my way through the issue starting with the non-mechanical east fix on down (drink cage on/off , original saddle back on/off, saddle bag on/off, tighten seat post etc.)

I never noticed that flawed finish before and when I raced last Sunday I went around and looked at all the BB's for the same frame - none had issues - so I was starting to think the worst. Nice to know it looks like I'll only have to do a touch up and can move BB to the bottom of my troubleshooting list.

531Aussie

It still might be worth checking if both sides are tight enough, and that the cups are flush with the outside of the frame.

The BB tool isn't expensive, so you can probably check it yourself

There are two different tools I know of which do the job