Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 03-03-11, 12:16 PM   #1
Lawrence08648
Advisor
Thread Starter
 
Join Date: Mar 2008
Location: Central New Jersey
Bikes:
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Anyone every grease sealed bearings?

I just read an article about greasing sealed bearings. You carefully pop off the black plastic seal, put grease on top of the bearings and then put the seal back again. Has anyone tried this? When you did it, were the bearings dry? How easy does the plastic seal come out? How easy is it to damage the plastic seal? How do you damage it, rip it? Bend it? What happens if you damage it, what do you use to replace it?
Lawrence08648 is offline   Reply With Quote
Old 03-03-11, 12:28 PM   #2
davidad
Senior Member
 
Join Date: Feb 2009
Bikes:
Posts: 4,827
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
I have cleaned and regreased sealed radial bearings. You need to be careful when popping the seals out. The seala metal backing that can be bent, but you can straighten it if necessary.
I like these bearings because the retaining ring is easy o remove and replace. http://www.enduroforkseals.com/id138.html
davidad is offline   Reply With Quote
Old 03-03-11, 12:32 PM   #3
MileHighMark
Old. Slow. Happy.
 
MileHighMark's Avatar
 
Join Date: Jan 2010
Location: Boulder County, CO
Bikes:
Posts: 1,798
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It's definitely not difficult, but you need to be careful removing the seal(s). Use an x-acto knife and pry from the outside of the seal (to avoid damage). I've done this several times, and it's always been worth the effort.
MileHighMark is offline   Reply With Quote
Old 03-03-11, 01:32 PM   #4
Charles Ramsey
Guest
 
Bikes:
Posts: n/a
Mentioned: Post(s)
Tagged: Thread(s)
Quoted: Post(s)
The way ALCOA does it they put the bearing in a can of grease then they put the can of grease in a vacuum chamber and suck out all the air. When the vacuum chamber is repreassurized the grease is sucked into the bearing.
  Reply With Quote
Old 03-03-11, 05:28 PM   #5
dvs cycles
Senior Member
 
Join Date: Oct 2007
Location: SoCal
Bikes:
Posts: 1,163
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Charles Ramsey View Post
The way ALCOA does it they put the bearing in a can of grease then they put the can of grease in a vacuum chamber and suck out all the air. When the vacuum chamber is repreassurized the grease is sucked into the bearing.
Sounds like a good use for my food saver bags.
dvs cycles is offline   Reply With Quote
Old 03-03-11, 06:46 PM   #6
reptilezs
Senior Member
 
Join Date: Sep 2004
Location: boston, ma
Bikes:
Posts: 2,852
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
a utility knife easily pops out the seals. the cartridge can be disassembled or flushed with solvent. to disassemble push out the retainer and drop the balls to the bottom, then separate the races
reptilezs is offline   Reply With Quote
Old 03-03-11, 07:42 PM   #7
Lawrence08648
Advisor
Thread Starter
 
Join Date: Mar 2008
Location: Central New Jersey
Bikes:
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by dvs cycles View Post
Sounds like a good use for my food saver bags.
I thought about it. I won't push the grease into the bearings. It will suck out the air while leaving the grease and the bearing there, separated. It won't work.
Lawrence08648 is offline   Reply With Quote
Old 03-04-11, 12:17 AM   #8
3alarmer
Can'tre Member
 
3alarmer's Avatar
 
Join Date: Nov 2010
Location: The Big Tomato
Bikes: old ones
Posts: 13,735
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 274 Post(s)
Quote:
Originally Posted by Lawrence08648 View Post
I thought about it. I won't push the grease into the bearings. It will suck out the air while leaving the grease and the bearing there, separated. It won't work.
Hence the terminology ?
Quote:
sealed bearings
3alarmer is offline   Reply With Quote
Old 03-04-11, 09:17 AM   #9
jgedwa
surly old man
 
jgedwa's Avatar
 
Join Date: Sep 2006
Location: Carlisle, PA
Bikes: IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
Posts: 3,345
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by 3alarmer View Post
Hence the terminology ?
Well, they are not really sealed. Its really not practical for the seal on a bearing to be truly air-tight. It does have to turn, afterall. Sealed bearings just have more of a barrier than otherwise. Keeps out the big chunks of air and such.

jim
__________________
Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
--------------------------
SB forever
jgedwa is offline   Reply With Quote
Old 03-04-11, 09:22 AM   #10
Charles Ramsey
Guest
 
Bikes:
Posts: n/a
Mentioned: Post(s)
Tagged: Thread(s)
Quoted: Post(s)
It does work ALCOA had some severe service bearings where the grease would boil out leaving them full of air. My father was working on a way to pump molten aluminum using magnetohydrodynamics. It seems molten aluminum is hard on regular pumps go figure. Of course this method does not remove any dirt or old grease in the bearings.
  Reply With Quote
Old 03-04-11, 10:00 AM   #11
canopus 
Senior Member
 
canopus's Avatar
 
Join Date: Mar 2009
Location: Kingwood, TX
Bikes: 1985 Cannondale SR300, 1985 Cannondale ST400, 1984 Trek 760, 1984 Trek 610, 1984 Trek 720, 1981 Trek 710, 1979 Trek 710, Gary Littlejohn Cruiser, BMX
Posts: 1,218
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yes, did it alot especially after the lake jumping runs as a kid. As others have said, you just have to be careful removing the seals (If I used an exacto knife it would be a DULL one) I prefer the small pin/curved hook tools from Snap-On (or Harbor Freight if on a budget).
__________________
1984 Cannondale ST
1985 Cannondale SR300
1980 Gary Littlejohn Cruiser
1984 Trek 760
1981 Trek 710
Pics
canopus is offline   Reply With Quote
Old 03-04-11, 11:10 AM   #12
Burton
Certified Bike Brat
 
Burton's Avatar
 
Join Date: Jan 2011
Location: Montreal, Quebec
Bikes:
Posts: 4,251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Cleaning and greasing sealed bearings is the EASY part

In fact its pretty straightforward with most sealed bearings.

What I`ve never been able to do is evaluate the condition of the bearing races to confirm that the bearing was indeed still in perfect shape. The ball bearings are harder than the race so their condition isn`t a good indication and the bearing cages block any inspection of the races themselves.

So regreasing and reinstalling sealed bearings is pretty much a crap-shoot. Just because it spins freely after cleaning is no guarantee its in good shape. Bearings only perform as designed (or not) under load.
Burton is offline   Reply With Quote
Old 03-04-11, 01:42 PM   #13
mrrabbit 
Senior Member
 
mrrabbit's Avatar
 
Join Date: Dec 2007
Location: San Jose, California
Bikes: 2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed
Posts: 3,190
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It's easy...do it when the bearing have sat for several years and the problem has become caked grease as opposed to worn units. Spin afterward for about 5-10 minutes and voila - they feel like new. Does nothing for bad units though. Everything has to be replaced at some point.

=8-)

Razor blade type knife seems to be a good tool.
__________________
4000+ wheels built since 1984...

Disclaimer:

1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:

Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
mrrabbit is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 09:10 AM.