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-   -   New bottom bracket tightness (https://www.bikeforums.net/bicycle-mechanics/327167-new-bottom-bracket-tightness.html)

gmason 07-30-07 03:09 PM

New bottom bracket tightness
 
I replaced my Deda D-Force BB with a Campa Centaur today (while changing from two to three ring crankset). The Deda was torqued really well, so I assume correctly and to their full spec by Casati when they installed it. I have ridden it for over two years with no issues, and it sounds good even now - very smooth.

On the Campa, after installing both sides and torquing the right to spec (70Nm), I did the left as directed. At 70Nm it felt almost seized - very hard to turn with fingers. I backed it off, and re-torqued to 30Nm as specified with Loctite blue.

Now it is just a little stiff, but smooth. I will assume for the time being that the bearings will wear in OK, but wonder about your similar experiences.

BTW, it is the new style BB, using the cassette lockring tool for assembly.

HillRider 07-30-07 05:08 PM

Sounds like the bb shell isn't exactly parallel and could use facing.

neil0502 07-30-07 05:09 PM

Were the bb shell threads clean, chased, and faced (at least clean and chased)?

Seems you followed the manual pretty well to the letter. Also from their installation pdf

http://www.campagnolo.com/pdf/722521...om_bracket.pdf

"The bottom bracket cage may be deformed or the supports are no longer axial. In this case, unscrew the left hand support, apply the threadlock, then re-tighten to a torque setting of 30N-m or 22.13 lb-ft."

Can you verify that your BB shell is okay?? Maybe it's worth a chase & face....

http://www.parktool.com/repair/readhowto.asp?id=106

gmason 07-30-07 05:10 PM

Hillrider: I kinda' figured that, but with the Deda being perfect, I guess that means that tolerances differ.

neil0502 07-30-07 05:11 PM

[insert obligatory "Campy is just that much better" comment here]

gmason 07-30-07 05:12 PM

neil0502: Threads were clean, and as you said - I followed the directions (what a concept :p ). But with 14 years of my 41 year career at NASA, I got used to that early.

gmason 07-30-07 05:13 PM

Quote:

Originally Posted by neil0502 (Post 4966493)
[insert obligatory "Campy is just that much better" comment here]

That IS true, of course. :D

neil0502 07-30-07 05:23 PM

Quote:

Originally Posted by gmason (Post 4966503)
neil0502: Threads were clean, and as you said - I followed the directions (what a concept :p ). But with 14 years of my 41 year career at NASA, I got used to that early.

14 years at NASA?

How did you get past the analysis, meetings, more meetings, theorizing, sketching-it-out-on-the-white-board, and what-if scenarios long enough to actually install the sucker in the first place? :D

gmason 07-30-07 06:29 PM

Quote:

Originally Posted by neil0502 (Post 4966596)
14 years at NASA?

How did you get past the analysis, meetings, more meetings, theorizing, sketching-it-out-on-the-white-board, and what-if scenarios long enough to actually install the sucker in the first place? :D

Just lucky, I guess. :p

gmason 07-31-07 01:54 PM

I rode the new setup about 25 miles today. Lots of climbing and rolling terrain. No noises or roughness at all from the BB. After I got back, when rotating the pedals it feels as though things loosened up a bit.

Interestingly, I returned to a friend's email, in which he said he had the same issue when installing his. It died after 10,000 miles! I figure I will be in my 70s by then, so I think I am OK. :p

Also - as a sidenote - when I switched my Protons (13-29) for Zondas (11-29 custom cassette) initially, I had to readjust the rear der to get good shifting. That was in 2005, so who knows. Yesterday during the rebuild I put the Protons back on, along with my first ultra-narrow chain. No adjustment necessary for the rear der. I guess I am a believer in the new chains.

neil0502 07-31-07 02:12 PM

Quote:

Originally Posted by gmason (Post 4973061)
I rode the new setup about 25 miles today. Lots of climbing and rolling terrain. No noises or roughness at all from the BB. After I got back, when rotating the pedals it feels as though things loosened up a bit.

DID it loosen up, though? Did you stick the torque wrench back on it to see if you could verify it, quantitatively?

[cough]chase and face[cough, cough]

I think I'd still recommend it. Otherwise, you're going to be vexed by the cycling equivalent of a silly piece of foam not sticking to the shuttle exterior correctly (or some similar JPL analogy....).

gmason 07-31-07 03:09 PM

Quote:

Originally Posted by neil0502 (Post 4973202)
DID it loosen up, though? ...

Sorry, I could have used a better term. I meant that the spindle freed up. My assumption (I know, never ...) is that with the reduced torque on one side, the bearings have a little leeway to adjust. But no, I have not checked its torque setting again. Will do.

And I agree that at some point I should (will) have the BB shell reworked.

BTW, I was at GSFC, not JPL. ;)

HillRider 07-31-07 03:50 PM

Quote:

Originally Posted by gmason (Post 4973061)
Interestingly, I returned to a friend's email, in which he said he had the same issue when installing his. It died after 10,000 miles! I figure I will be in my 70s by then, so I think I am OK. :p

That sounds like premature failure to me. I've had two Shimano UN72 square taper bb's last over 30,000 miles each and still be in good condition when replaced as part of a crank upgrade. I have 11,000+ miles on an Ultegra-level Octalink bb and it's still smooth as glass. I would expect a Campy bb to do at least that well.

HillRider 07-31-07 03:56 PM

Quote:

Originally Posted by gmason (Post 4973061)
Interestingly, I returned to a friend's email, in which he said he had the same issue when installing his. It died after 10,000 miles! I figure I will be in my 70s by then, so I think I am OK. :p

That sounds like premature failure to me. I've had two Shimano UN72 square taper bb's last over 30,000 miles each and still be in good condition when replaced as part of a crank upgrade. I have 11,000+ miles on an Ultegra-level Octalink bb and it's still smooth as glass. I would expect a Campy bb to do at least that well.

gmason 07-31-07 04:16 PM

Quote:

Originally Posted by HillRider (Post 4974010)
... I would expect a Campy bb to do at least that well.

I certainly would like to think so, but BBs have been a weakness.


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