Bicycle Mechanics - loose-ball BB keeps loosening

Hey all,

My loose ball BB keeps coming loose (or misadjusted) after riding a few miles.

When I first install it, I make sure it is properly adjusted (no play, I check with the crankarm attached). Then I crank down really hard on the lockring, making sure to hold the adjustable cup in its proper position. Again, I check to make sure there is no play.

But after a short ride, there will be noticeable play in the cranks. The lockring doesn't feel loose. It just feels like it is misadjusted.

Any ideas?
Thanks

Are you sure it's the BB not the crankarm that is coming loose because when they fal off once they get wider, and fall off every few miles

http://bikeforums.net/showthread.php?t=413985
(http://bikeforums.net/showthread.php?t=413985)

Does the BB use retainer rings for the ball bearings? Are you sure you have them in correctly? If you put them in backwards, then you will experience the problem you describe.....you might want to just double check. Its easy to do as I've done it myself......

Does the BB use retainer rings for the ball bearings? Are you sure you have them in correctly? If you put them in backwards, then you will experience the problem you describe.....you might want to just double check. Its easy to do as I've done it myself......

Which would be the right way round??

would the part at the front of this pic be facing inside (towards center of bike)?
http://i249.photobucket.com/albums/gg201/jacktaylor-timmy/bbring.jpg

Which would be the right way round??

would the part at the front of this pic be facing inside (towards center of bike)?
http://i249.photobucket.com/albums/gg201/jacktaylor-timmy/bbring.jpg

Who cares. You shouldn't be using retainers when you repack a bb anyways. Toss the retainers and reinstall.

Which would be the right way round??

would the part at the front of this pic be facing inside (towards center of bike)?
http://i249.photobucket.com/albums/gg201/jacktaylor-timmy/bbring.jpg
If you continue to use the retainer (I agree they aren't necessary but are a convenience) the top of the part in the picture should face the cups, i.e. should face outward away from the center of the bike.

If you continue to use the retainer (I agree they aren't necessary but are a convenience) the top of the part in the picture should face the cups, i.e. should face outward away from the center of the bike.

Ah thanks

That's why it was wrong when I set it up then :o

Yes, it is indeed play in the bottom bracket and not in the crankarms. The BB does use retainers,and I do have them with the balls towards the cups.

One other issue is that the lockring is a generic one that did not come with the BB (Hatta Swan). I will look for a higher quality lockring, although I don't see how that would be causing the problem.

I may also try to run the BB without retainers, as suggested, to see if that has any effect.

In the meantime, any other suggestions?
Thanks

A lock ring is a lock ring. As long as it keeps the adjustable cup from turning, it's doing its job!

Going to loose balls over a retainer will make the bb run smoother and longer... the retainer is there to make assembly easier and in a place that has to sustain high torque loads, having more bearings is a good idea.

Use grade 25 bearings and a a good deal of quality waterproof grease (marine grease is excellent) and you will be a happy camper... if the lockring is poorly threaded or there is some wear or damage to the cup's threads this might explain why things are loosening off.

Sounds like your fixed cup is coming loose. Be sure its on very tight.

taking out the retainers entirely seems to have solved it thus far... thanks all

Which would be the right way round??

would the part at the front of this pic be facing inside (towards center of bike)?
http://i249.photobucket.com/albums/gg201/jacktaylor-timmy/bbring.jpg


Rounded side of the retainer goes toward the inside of the BB. In other words, the rounded sides of the left and right bearings face toward each other. Flat side goes out toward the crank arms.

Ideally, you will use loose bearings and toss the retainer. However, if you do this you have to add bearings. Make sure the bearings are all the same size or replace all of them.

Rounded side of the retainer goes toward the inside of the BB.
???
The side facing up in the pic goes against the cups.