On 7/3/2019 10:31 AM, jbeattie wrote:
On Tuesday, July 2, 2019 at 10:16:21 PM UTC-7, James wrote:
On 3/7/19 2:42 pm, James wrote:
On 3/7/19 12:04 am, jbeattie wrote:
On Tuesday, July 2, 2019 at 5:16:41 AM UTC-7, AMuzi wrote:
On 7/1/2019 11:09 PM, jbeattie wrote:


More convenient -- whether they're better, I don't know. It looks
like a standard cartridge bearing.Â* I don't know why it would
fare any better than any other quality cartridge bearing, but
maybe they're special in some way.

-- Jay Beattie.


Different quality bearings with the same bearing number can have
dramatically different wear and longevity. This isn't news.

Absolutely, but from what I can tell, both the Campy and Shimano
cranks use a 6805N-2RS, probably with ABEC 5/7 steel balls in the
mid-range, so I was wondering what distinguished the Campy OE
bearings. Are they some sort of super-steel? I've gotten a pretty
long life out of some bearings, but nowhere near 25,000 miles out of
a BB, assuming the frame and crank lasted that long.

Perhaps also the seal in the Campag cup helps stop rusty water from
getting to the bearing from the inside?

I don't do much wet weather riding, but I read on a forum just now "In
my experience, Campag's bearings are amongst the best; mine lasted well
over 10,000km of all-weather commuting."

My frame is also fairly well sealed from moisture, so it appears.Â* I
don't find water dripping from the BB drain hole after a wet ride, and I
haven't found rusty residue in the BB shell at times when I remove the
cranks.Â* The bearing grease always looks pretty clean too.


I should mention that before I got my first UT cranks, I had used both
Shimano and Campag "sealed" cartridge BB assemblies, and they would last
maybe one season if I was lucky. Mostly they would start making noises
well before that.

I have mates with Shimano cranks & BB with outboard bearings, who suffer
clunks and creaks from the BB, and the occasional left crank that drops
off because the 2 little pinch bolts weren't tight enough. Obviously
the mechanic's fault, or the engineering. I figure a single big bolt
that holds the axle halves together, and a wire clip to locate one
bearing in the housing is simple and robust enough for most amateur
mechanics to get right.

I haven't had a problem with the pinch bolts except ruining a head and having to drill/bolt-extractor it. The socket heads are relatively soft (even using spec'd torque and a good bit). They do require some care. I imagine that if you talked to enough UT users, you will find someone whose center-bolt came loose. Any fastener can loosen. And any threaded cup can creak, even UT cups per internet reports.

My personal belief is that a lot of BB creaking is not the BB. Like I mentioned, I replaced the BB30 bearings on my commuter after a couple of years believing that they were creaking, and they weren't. It was the stem and headset and probably the HS compression nut in the steerer. I get clicking out of he rear axle/dropout interface that is "unmistakably" from the BB. Anyway, I now have some nice new BB bearings in my commuter installed with Loctite 609. The bike is creak/click free, which is kind of weird since it is a Cannondale aluminum CX frame, renowned for being a one-man band.

I've had "bottom bracket noises" that turned out to be from the quill
stem, from a slightly loose chainring bolt, and on one bike, from the
saddle itself. The soft saddle parts were somehow creaking against the
saddle's wire frame.

Of course, I've also had genuine BB noises. But bike noises can be
devilish things to trace.


--
- Frank Krygowski