Ugh, annoying - another dead BB

[cydewaze]

I was cleaning my bike today after my wife and I rode the Bay Country Century on the tail end of Ernesto. Both of our bikes were a muddy mess, covered with all sorts of plant life and mud.

I got my wife's Fierte cleaned up, then moved onto my bike. It has a 7700 series Dura-Ace BB that I've had problems with before. A year ago, the BB shell on my bike came unbonded from the frame, which gave the impression that the BB was loose. I ended up over-tightening it, which pitted the cones. I ordered a new pair of cones, and the LBS used them when they swapped my parts over from my old frame to the warranty replacement frame.

Lately, I've been getting some BB area noise again, and during my post-Ernesto clean up, I pulled the BB out. Cones are pitted AGAIN! Ugh!

How hard can it be to install a 7700 BB without hosing the cones? I'm almost considering a new crank/BB to put this problem behind me once and for all.

[pale scotsman]

I'd throw in an Ultegra BB and forget about it.

[nm87710]

ditto what the scotsman said

6500 BB is industrial strength. ~60 grams heavier

[stevep]

ditto, ditto.
ultegra way better.

[cydewaze]

Yeah, I know I can throw a new BB at it, but I'd like to know what's causing the current one to get trashed. Is it possible the bearings themselves got screwed up from the first cone pitting?

[csm]

you didn't replace the bearings and the cones?

[cydewaze]

you didn't replace the bearings and the cones?
Nope. Couldn't find the bearings seperately short of getting a whole new BB.

[J.Greene]

Nope. Couldn't find the bearings seperately short of getting a whole new BB.

Shimano (and most others now unfortunately) bottombrackets are throwaway items. The ultegra is the most durable though. I wouldn't expect another DA BB to last more than a year or so of hard riding either.

JG

[mgm777]

Cyd,

I'm not sure what is causing your specific problem, but the 7700 series DA BBs are notoriously fragile. As others have said, the Ultegra BB is a slightly heavier, but much, much better and more durable design. I went through a similarly frustrating experience...my 7700 BB woud work fine for about 3K miles, then start making noise, sounding loose, turn rough, etc. I went through two iterations of the DA BB, before I put the Ultegra in there. Absolutely no problems in over 5K miles since. Good luck.

Michael

[cydewaze]

Shimano (and most others now unfortunately) bottombrackets are throwaway items. The ultegra is the most durable though. I wouldn't expect another DA BB to last more than a year or so of hard riding either.
Well then I guess that would explain it! This is my 3rd season on mine. Guess I'll just grab an Ultegra and call it done.

FWIW, my old 7400 DA sqare taper BB, now on my spare bike, is still going strong.

[stevep]

those da bbs stink.
bad design... require a lot of maintenance, hard to install buut they are light i guess.
the ultegra are awesome.

[cydewaze]

those da bbs stink.
bad design... require a lot of maintenance, hard to install buut they are light i guess.
the ultegra are awesome.
lol, well it was $30 bucks, so no loss. Just ordered a 6500. Should have better luck with that.

[vaxn8r]

I'll vouch for what everyone says. 3 years on one of those DA BB's is pretty good actually. I'd bet you could get 10+ years on an Ultegra BB.

[Brian Smith]

Those D-A BBs are a throwback to the days when bottom brackets needed to be finely adjusted to achieve their longest lifespan and minimum friction, and then frequently regreased and readjusted. If the ounces are more important than the time and sometimes money to maintain them, then keep at them. Otherwise, and for everyone these days it really should be otherwise, I'd say use the Ultegra as everyone else here so far has recommended.

The specific cause is most likely a lack of attention to:
a) maintenance
b) setup and adjustment
c) frame prep

The Ultegra would be a cure for each of those causes.

[obtuse]

the newest d/a 7700 series bb uses cartridge bearings and is what you should get. the old needle bearing d/a bb was awful; but really really smooth when you took the dust seals out, lubed it with clock oil and replaced the bearings with ceramics. of course, they then lived for ten minutes instead of the fifteen they normally lived.

obtuse