Metro50

What's up guys!
Recently purchased a used 2009 Cervelo S2 with SRAM Red groupset and discovered
a glitch in my bottom bracket.

It was making a grinding noise on the 18/19 & 20th gear only.
And, it was only upon the first revolution.

I took the liberty to confirm a few things to eliminate other possibilities.

* Tightened Crank outer ring (which all the bolts were loose)
* Tightened the pedals
* Tightened the Bottom bracket.
* Seems the chain is 1 link too long (will shorten after replacing or getting another shell or adapter that got shredded)

Ordered the Park grease a few days ago and received the Park BBT-9 tool today.
So, I loosened the bottom bracket rings.
And, upon opening up the non driver side, a warped ring fell out.
And upon looking inside the ring there seemed to be a shredded up rubber lining of some sort.

Please see attached for any confirmation & exact name of part that needs to be replaced.

All pieces (Should this be 1 piece?)





Warped ring




View of covered portion the broken pieces came from>>





I am either thinking about replacing the entire bottom bracket for simplicities sake or
replace the part if it's recommended.

ANY comments, opinions or direct links to this case would be great.
This is my first bottom bracket experience, so all comments are more than welcome.
thx!

rpenmanparker 

The warped ring is not broken. It is perfectly okay. This is called a wave washer and is supposed to be that way. It serves to provide pre-load to the crank assembly. The waviness is basically a spring. The rubber thing is likely just a seal ring. You might be able to get a replacement. Don't you use your LBS (local bike store)? They may have a seal or can get you one in the crank or bottom bracket brand. You don't need a new bottom bracket or crank.

Noise that is specific to rear cogs (cassette sprockets) has to do with the chainline, front derailleur positioning and tuning, or rear derailleur adjustment. Look for the SRAM installation instructions for these components and you will find how to adjust everything to work properly. Most likely the chain is rubbing on the rear derailleur at that extreme a chain angle, or the rear derailleur is not properly adjusted and the chain is slightly over or under-shifting.

Now for some generic advice:

Gears on a bike aren't numbered. For folks to know what you are talking about specify the front sprocket (large or small) and the rear cog (as in third largest or second smallest or third from the left looking forward from the rear). The way you did it is non-specific and confusing.

Finally, you will get better mechanical help on the Mechanics Forum instead of the Road Forum. The Mechanics Forum is where the truly expert wrenches spend most of their time.

Good luck.

Metro50

Hey, thanks for the quick input!
I was wondering what is the specific part of that piece that needs to be replaced?
And, is it 1 piece?

The entire analysis of your reply I have done this>>>

"Noise that is specific to rear cogs (cassette sprockets) has to do with the chainline, front derailleur positioning and tuning, or rear derailleur adjustment. Look for the SRAM installation instructions for these components and you will find how to adjust everything to work properly. >>>I Have done this prior to this post.

Your quote>>
"Most likely the chain is rubbing on the rear derailleur at that extreme a chain angle, or the rear derailleur is not properly adjusted and the chain is slightly over or under-shifting" I don't think it is rubbing on the rear derailleur as the noise
sounds like it is coming directly from the bottom bracket. I also have another bike that doesn't make this noise and can only go to the 2nd to last small gear on a 10 speed bike on the large crank.
The chain tension on the S2 is looser than my other road bike and heard this can be the culprit? may be a combination
of both this PLUS the shredded up pieces covering the ring inside the bottom bracket? not sure as this is my first
experience on this.

Although I appreciate the constructive criticism at the end I was under the assumption this was the
road bike section and not a mt. bike thus specifying the cog #'s assuming it was a gimme. So, not sure how that would be confusing. But, guess everyone has there own mentality. no harm no foul.
I will check the Mechanics forum as you mentioned. appreciate your insight though.
thx.

rpenmanparker 

Sorry, I meant rubbing on the front derailleur. My mistake.

rpenmanparker 

About the gear naming. It is not my mentality. On the contrary, I was doing what you are doing. I had to learn it at the beginning so I could communicate with the other folks. That is just how it is.

pdedes

SRAM bb30, older generation, came with a wave washer and some plastic spacers to fine tune drive line. It's likely the "shredded rubber" is one of the plastic spacer washers. Use the SRAM instructions to reinstall correctly.

Metro50

thx pdedes.
Since these Bottom brackets are pretty cheap I just went and got a new one for 25 bucks on ebay.
But, will keep this in mind in the future.
thx!

pdedes

I buy the bearings for $6 at a local bearing wholesaler

Metro50

It wasn't the bearing that had to be replaced unfortunately.
but thx.