bottom bracket roughness

T? Burtim said:

I removed my sealed BB on a Trek 1000 to try and find clicking noise. After I got it out a noticed
a catch in it as it turned. It seems to spin OK but there is a definite notch in the bearings or
spindle. Is there any way to break it down? Is this normal for sealed cartridge BB? The bike has
app. 2000 miles on it with no serious crashes or damage from the elements. I would have thought
the sealed cartridge would last longer. Thanks for any advice.

Intermittent or random clicks of variable sharpness from ball bearings are caused by rust. Amazingly
tiny particles of rust will cause major clicks, so much so that when inspected, the lube can appear
uniformly pink as though that were the original color of the lube. In most cases, especially with
cup-and-cone bearings, cleaning is easy and re-lubricating will return the unit to service. Even
cartridge bearings can be cleaned by removing the seals, that are invariably there, and replacing
them after cleaning and repacking with automotive wheel bearing grease.

Jobst Brandt [email hidden] Palo Alto CA

"TBurtim" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

I removed my sealed BB on a Trek 1000 to try and find clicking noise.

After I

Quoted message said:

got it out a noticed a catch in it as it turned. It seems to spin OK but

there

Quoted message said:

is a definite notch in the bearings or spindle. Is there any way to break

it

Quoted message said:

down? Is this normal for sealed cartridge BB? The bike has app. 2000 miles

on

Quoted message said:

it with no serious crashes or damage from the elements. I would have

thought

Quoted message said:

the sealed cartridge would last longer. Thanks for any advice.

"Sealed cartridge" as you say crank bearing assemblies exist for one reason: They save assembly time
and money. No one pretends they are as good as the loose-ball models they replaced.

You are not important in the greater scheme of these trends nor am I. The customers who count are
the factory manager and the bike designer. If a bicycle can be produced ten seconds faster or ten
cents cheaper with any given gimmick or technique then that will quickly become the norm. (cf.
Aheadsets).

Not to say these cannot be done well. Phil Wood and later Mavic, Stronglight and others did a fine
job of it. But not within the cost constraints of a Trek 1000. If Trek were to offer an unreasonably
high quality component someplace on the bike they would risk being uncompetitive with other brands
by $5 or $10 and heads would roll. Therefore you have this thing in your frame as do everyone else
who owns a similarly priced major brand bike of the same year.

If it bothers you there are a plentitude of better BBs available.
--
Andrew Muzi yellowjersey.orgyellowjersey.orgOpen ↗ Open every day since 1 April 1971

TBurtim said:

I removed my sealed BB on a Trek 1000 to try and find clicking noise. After I got it out a noticed
a catch in it as it turned. It seems to spin OK but there is a definite notch in the bearings or
spindle. Is there any way to break it down? Is this normal for sealed cartridge BB?

No and no. Toss it. $35 for a good replacement. Get the numbers off of it before you ashcan it.

Quoted message said:

The bike has app. 2000 miles on it with no serious crashes or damage from the elements. I would
have thought the sealed cartridge would last longer.

Should, but I just replaced mine, and it had maybe 4000-5000 on it. with little of that in the rain.

--

David L. Johnson

__o | If all economists were laid end to end, they would not reach a _`\(,_ | conclusion. --
George Bernard Shaw (_)/ (_) |

TBurtim said:

I removed my sealed BB on a Trek 1000 to try and find clicking noise. After I got it out a noticed
a catch in it as it turned. It seems to spin OK but there is a definite notch in the bearings or
spindle. Is there any way to break it down? Is this normal for sealed cartridge BB? The bike has
app. 2000 miles on it with no serious crashes or damage from the elements. I would have thought
the sealed cartridge would last longer. Thanks for any advice.

I'd expect to get at *least* 2x that. I'm guessing that you get water in it. Probably cheap seals.

I tried to disassemble a Shimano sealed BB and found that it wasn't designed to be user serviced
(i.e., I trashed it during disassembly -- but I started with one that I had just replaced just
in case 🙂).

Up to you whether you continue to ride it or replace it. It's not going to critically fail and you
could just wait for it to get loose. But, they're cheap enough and easy enough to replace that if
it's bothering you -- just replace it. But, I'd consider upgrading from what's in there when you do
replace it 🙂.

David

"David L. Johnson" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Quoted message said:

Is there any way to break it down? Is this normal for sealed cartridge BB?

No and no. Toss it. $35 for a good replacement. Get the numbers off of it before you ashcan it.

Eeek, UN52, $20, everywhere.