Replace bearings when repacking hub?
 

I decided to overhaul the hubs on my road bike (Trek 1000C). The front has pitted cones, but the races looked good, so I'm just replacing the cones and bearings. On the rear everything looks good (bearings, races, cones). While I have the rear apart, should I go ahead and replace the bearings? What's the consensus on replacing bearing that show no signs of problems? I have the bearings. They're cheap, so that's not the problem. Do bearings "take a seat" to the cones & races (like brake pads)? Meaning that the new ones might loosen up after a few hundred miles.

I generally will replace them if they have a few seasons on them. They cost very little and you allready have the hub apart.

I also always replace them if I open the hub up. This seems to be the conventional wisdom. However, I don't have a way to reliably measure bearing or their smoothness to know if there are issues only with the bearings. When I have rough wheels, it always seems to be pitting in the cones...not bearings.

That's how I see it. New ball bearings will set you back a couple of bucks at most. And since there is no easy way to measure the old bb's for wear, replacement should be a no-brainer...

If the ball bearings are not Shiny even the slightest bit dull replace them if they look shiny new leave em in unless your going on a tour.
I just finished servicing some Campagnolo hubs all shiny so back in and I always lightly foil the hubs with aluminum foil.
The Aluminum foil will show you exactly how much wear is on the cone because the race where it is worn will turn grey immediately even after a few hundred miles..
I wrap the axle in duct tape or use and old axle then put the cones on and spin while holding aluminum foil on it. it takes about 1 second to see the wear...
Then I wipe it off and either replace or reuse.

I replace them if I have the bearings available. Otherwise I go by their appearance after being cleaned of residual grease. If they're nice and shiny they should be ok to reuse. If they look dull then I'll go buy replacements before putting the hub back together.

For a dollar/wheel, it's not worth the time to clean, inspect and hope you didn't miss something + you keep your hands a lot cleaner.
Clean grease washes of the hands with cheap bar soad.
Dirty grease doesn't.
Just wipe out the old grease with a used paper towel you drained your bacon on that morning.

Bill
I don't miss anything it's 9 or 10 or 11 bearings I use two magnets and I like to know the condition of my stuff... bearing wear would indicate cone wear.
It is interesting That I take a class from a well respected builder and racer he has no trouble getting his hands dirty neither do I I actually touch the chain when I clean it without gloves!

Also that's Just LAZY why replace what does not need to be replaced? I wish we could use bacon grease for bicycles the Men's Room would love to hear that story... Maybe I'll try that just for fun...


Flame on

Using a magnet to extract/manipulate the BBs, you run the risk of magnetizing them, causing them to attract ferrous wear particles in the vicinity. New BBs are so cheap, it's a no-brainer.

I don't know if magnetizing the balls is a real problem or just theoretical. However, while I use a magnet to be sure all of the old balls have been removed I position the new ones with a large pair of tweezers.

Thanks for the comments. All bearings have been replaced. I finally have my road bike road worthy again. Now if the weather would just cooperate....

I get my hands dirty quite often, but I'm not stupid enough to do it if not necessary!
Why waste time & solvent?
I can look at the bearing race in the hub to see if there's a "wear" problem!
Do you you use an "organic" cleaner and then wash the old grease down the drain?

+1
+1