psuaero

I've got about 3,200 miles on my Scattante CFR since last August. When I first got the bike I was amazed at how quiet is was over the mostly chip sealed roads and generally bad asphalt of the northeast. Lately (the last few hundred miles), I've noticed more noise while hitting cracks in the road or sharp bumps. The noise is best described as "chatter" and sounds like the bottom bracket area. The noise seems to be most pronouced when coasting fast over bad sections. It also seems to be less noticeable when I'm putting more power into the pedals. For instance, just soft pedaling over bumps I can still notice it but really hammering on the cranks and the noise seems to disappear. When I spin the cranks on my work stand without the chain attached they seemed very smooth and quiet.

The drivetrain is all Ultegra 10speed (not sure what actual bottom bracket is inside, Ultegra?). I've never taken apart the crank or bottom bracket of any bike. Is this something I should leave to a shop mechanic? Is there some periodic maintenance that is supposed to be done to the BB that I've been lax in doing over the last 11 months?

Retro Grouch 

Chain slap maybe?

bidaci

I vote on the chain too. Maybe some stretch on the shifter cables allowing a slight misalignment of the chain. Take a look at the Park Tool website and see if you think you an do the adjustments.`

psuaero

I really didn't think it was chain slap since it sounds more like a high frequency chatter. It's hard to tell where noises come from on CF bikes. I also don't see any nicks or chips on the rear stays where the chain would have hit.

So I guess what I'm hearing so far is "I shouldn't disassemble the BB just to take a look". I have a basic toolset like the one pictured here.
I was comfortable doing a fork swap myself but haven't delved into the crank area just yet.

timmhaan

also check to make sure the cassette isn't lose. sometimes that will work itself lose over a few thousand miles and clatter over vibrations.

psuaero

That's definitely a possibility ... thanks for the idea. Now, if I could just leave work a little early. Hmmm.

psuaero

Well I used the cassette lock ring tool and my torque wrench last night. The lock ring seemed loose (I think it turned a little when I used my fingers) and spun probably 3/4 to 1 full turn before the torque wrench clicked. I'll know in a few hours if the tightening fixes my mysterious chattering noise.

Does that 3/4 to a turn seem out of the ordinary? Is this normal for about 3,000 miles usage over the past year?

Thanks,
John

psuaero

Well I used the cassette lock ring tool and my torque wrench last night. The lock ring seemed loose (I think it turned a little when I used my fingers) and spun probably 3/4 to 1 full turn before the torque wrench clicked. I'll know in a few hours if the tightening fixes my mysterious chattering noise.

Does that 3/4 to a turn seem out of the ordinary? Is this normal for about 3,000 miles usage over the past year?

Thanks,
John

timmhaan

yeah, that lock ring is a little strange. it sometimes takes a few spins before you can apply pressure to it with the wrench. mine is the same way.

psuaero

Problem solved. I did 30 miles last night and didn't hear any rattles.

Thanks guys.
John