I’ve been having some bottom bracket (BB) woes. Noticed a click on the top of the left pedal stroke so decided to re-grease the BB. Took it apart cleaned and re-greased everything, then put it back together.

Roll forward a week. I notice that my cranks sticking here and there, it gets progressively worse on the ride. I get it home and off the bike notice my bike has turned into a rain-stick (this provided no calming effect).

Queue another strip down of the BB. Upon inspection, I found all the bearings on the drive side were out of the cage, which now would no longer hold them. I pinched the cages with pliers to secure the ball bearings back in place, re-greased & repacked.

I lifted my bike out today for my cycle to work and jingle-jingle; LOOSE BEARING! Cycle to work was sub 3 miles so risked it. Want to take care of this ASAP, so my questions are:

1. I figure I am over-tighting the bottom bracket, causing the damage to the cage, however what else could cause it?

2. What size bearings does an Italian threaded BB take?

BB info:

  • Campagnolo Italian threaded
  • plastic sleeve is in two parts, the smaller part pushes into the other.
  • 2 caged bearings from memory 8/9 bearings in each cage.
  • Two screw-in cones, one locking.

Here are pics of my spindle: enter image description here

Brev. whatever that means enter image description here

  • "Italian threaded" doesn't tell us much apart from which way the BB threads into the frame. I suspect the best thing would be to take it to your local bike shop and ask them what size BB/bearings you need. – Olly Hodgson Jun 15 '12 at 12:05
  • @Criggie thanks. have deleted comment now as edit record is in place – Swifty Aug 27 at 21:52

Take everything apart,get all the grease out of the bb and feel inside where the bearings go,it should be fairly smooth,do this to both sides and compare the "feel" of each..If it doesn't feel right(burrs,cracks) there's your problem...I just replaced the bearings in my bike and they were 1/4 inch but your bearings will probally be metric in that general size,it's easy enough to find online...don't skimp on the bearings,get grade 25 bearings,there the best...amazon has them for short money and good luck

  • +1 The old campy cup/cone bearings on BB and hubs are very hard hard steel. The surfaces where the balls ride should be completely smooth almost like a mirror. You do have to get the hardest ball bearings for this. – Angelo Aug 18 '12 at 15:09

Note that most bottom brackets don't use a cage. Rather you get enough loose balls to fill the race, gob some grease into the race of the cup, press the balls into the grease, and install. The cage should not be necessary to hold the balls in place.

In your case you may want to consider replacing the cups, bearings, and shaft with a cartridge -- much less to go wrong.

That is a nice campy BB you have there.

If it is in good shape, keep it.

Make sure the bearing surfaces are not pitted or marred. I recommend running loose bearings, not caged. You might fit one more bearing in. If memory serves, they are 1/4 inch. If you want to keep the cage, you can push the old ball bearings out and replace them. Make sure all is clean.

On the clicking.... It might not be the bearing itself. Check that the bottom bracket bearing cups are tight in the frame. Also, make sure the bottom bracket shell ( part of the frame ) has not become deformed. If you run the bearing cups loose, they can pound out the bottom bracket shell, elongating it. ( I did that once, had to ream and re-tap the frame from french to italian ( they are the same thread per inch, different internal diameter, if memory serves, french is 35 mm, italian is 36 ). Both are right hand thread, so make sure your lock ring ( left side ) is tight, or it will auto loosen. ( English is right on right, left on left and avoids this ).

also, check that the crank arm is not greased, pulled on tight, and that the pedals are tight ( grease these threads ).

  • British threads left on right and right in left. But not really relevant to the question – Swifty Aug 9 at 14:54
  • This question is 6 years old, so the original poster has probably already found a solution. We have plenty of new questions that could use an answer. – ojs Aug 9 at 16:36

To question 1, if the bearings all came out of the cage just a week after a re-pack, I was wondering if it would be the bearing cage being inserted the wrong way round.

No doubt its a bit too little too late but who knows

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