Bottom bracket bearing retainer problem
 

Whenever I take apart my 3-pc. bottom bracket I find one or both of the bearing retainers damaged. The grease looks good as new, and plenty of it, but the retainer is broken, and the fingers that curl around to hold the bearings in place get uncurled, and there's usually some damage to the spindle wherever that happens. Last time, I replaced the spindle, both cups, and both retainers, but I just tore it apart the other day and found the retainer in the fixed cup was pulled apart and the spindle was chewed up on that side. What am I doing wrong?

I didn't have a spare retainer this time, so I put it back together without the retainer, with 11 loose bearings instead of the 9 in the retainer. Is there any reason not to do that on a permanent basis? That was standard on the bikes I had before this one.

No issue of running a BB with all loose balls provided you don't overload it with one extra. (you'll know right away because it won't adjust). The main purpose of retainers on bottom bracket and headset bearings is as a convenience in assembly. Imagine if they had to hand count and pack these in production volume on an assembly.

BTW- retainers normally don't undergo any strain in a bearing, so if you're having issues with them you're doing something wrong. Either you're putting them in backward which is very common, or you're not properly adjusting the bearing to extablish 100% contact with slight preload. When there's play in a bearing the loaded spindle presses down and the balls try to migrate toward the top which can tear a retainer apart. Even without a retainer the migration is a problem because it causes excess ball on ball friction under load, increasing wear.

So no retainer is fine, but be sure to get the adjustment right.

Thanks, FB. I must be adjusting them too loose. I always think of adjusting car wheel bearings, which someone showed me how to do once, tightening and then backing off a little. What does "100% contact with slight preload" mean? I've never heard that before.

The ideal bearing adjustment is zero play (for the reason I described). But it's impossible to get a perfect adjustment. So you have a choice of erring to the loose or tight side. Preload means that the bearing is slightly over tightened, and within a small range is preferable than too loose by the same amount (short Tech sheet from Timkin). Be aware that too much preload makes things worse again, so care and judgment are called for.

When I adjust a cup/cone BB I adjust until I can't feel any play, then I tighten a bit more (<1/8 turn), to ensure that I didn't err loose. If all is right I can feel the smooth slight drag of a loaded bearing, but it's still in the range of a loose adjustment. With experience you develop the feel for this. You can also attach the right arm before making the adjustment, which will help you feel any trace of play.

One problem with BB adjustment is that tightening the lockring pulls the left cup back slightly loosening the adjustment. You need to check for this when finished, or compensate for it in setting the adjustment.

Got it. Thanks for the very clear explanation. I've definitely been adjusting too loose. Wheels, too, though I haven't had any problem with them yet. I'll re-adjust the bottom bracket. Much appreciated!

Wheels are a bit different, so you're technique needs to be altered accordingly. First of all, while tightening a BB lockring loosens the bearing, tightening an axle locknut tightens it. Also the compression of the quick release compresses the axle slightly, and if the dropouts aren't perfectly parallel, they bow the axle which does the same thing. After adjusting, recheck in the bike with the QR closed. You want minimum drag, and no detectable play at the rim.

Yes, I've always noticed that the wheels don't spin quite so freely when installed, and wondered if I should make the adjustment looser to compensate. But it sounds like I've been doing them just right. That explains why my wheel hubs don't seem to wear nearly as much as my BB. Thanks again!

Sounds like your wheel bearings might be a bit tight if they don't spin as well after installation. You should be able to feel a little play in the axle when off the bike, then the QR tightening will remove that play. Too much play, and you'll still have a loose axle. Not enough play and the bearings will be tight.

I think I said that wrong. My wheels do spin freely when installed, and they keep spinning for a long time. But they feel tighter in my hand when I spin them, as compared to when they're off the bike. Maybe what I'm feeling is just the lack of play. I'll check that next time I take a wheel off. Thanks!

It's one of those hard calls. The perfect adjustment (installed) is just to the tight side of the zero play point. Any play noticeable at the rim is too loose, noticeable drag is to tight, someplace between those is spot on.

I have a pair of front & rear dropouts that I use during adjustment. I can clamp the hub on them then get a good feel by hand of play & drag. It's harder to feel drag when the wheel is on the bike. There are some other methods listed somewhere ... Sheldon Brown most likely.

Regarding bearing retainers - 11 loose balls is better than 9 in a retainer. Spreads the load out more. I just throw the retainers away.

The only place I use them is in 1-piece BBs (virtually impossible to install loose) and headsets out of convienence.

FWIW, some companies, e.g. Campagnolo, provided 11-ball retainers with their bottom brackets:
http://www.os2.dhs.org/~john/11-ball.jpg

Great! It makes me wonder why anybody uses 9-ball retainers.

But I like that idea of loose bearings. I only used retainers because that's what this bike had when I got it. All my bikes have been second-hand, and until this one they came to me with 11 loose bearings in each cup. I just copied what I found, and didn't realize it was an option. I had less trouble with those old bikes and their 11 loose bearings, even though I was making the same mistake back then when adjusting the bottom bracket. I've got a new spindle on order. When it comes, maybe I'll install it with all new ball bearings without retainers, just like old times.

Or maybe I should switch to a cartridge, assuming that's possible. Is that another option? A square-taper JIS cartridge? That would work, wouldn't it? I think I just need to buy some crank bolts and a splined wrench. Any opinions on whether it's a good idea to switch over? I gather that cartridges are much more widely used now, judging by the availability of parts. Do they last longer? It sounds like they don't take any adjustment, which I don't get around to as often as I should anyway, and which this forum thread shows I haven't been doing a very good job of. And it probably wouldn't be much more expensive, given that I keep having to buy new spindles and cups when I finally do get around to servicing the BB.

Yes, you could switch to a cartridge BB if you wish. Loose BBs are history now but I still like them. While a cartridge BB may last thousands or even tens of thousands of miles, a loose ball BB can last "forever" if undamaged and maintained properly.

I meant why 9 balls in the retainer instead of 11? Until John's post I assumed the retainers had 9 balls because that's all that will fit.

Most people assume that more balls is better, but that isn't necessarily true. If you look at this heavy duty industrial bearing you'll notice that there are fewer balls used than possible, separated a bronze retainer. This is a common design. I assume the makers and buyers know what they're doing, and want good quality, load and wear characteristics, and aren't trying to cut corners by skimping on balls.

This isn't offered as a technical explanation, but just to show that more isn't necessarily better.

Success! Thanks to the good advice in this forum, I've finally learned how to adjust a 3-pc bottom bracket correctly (and only, what, 10 or 20 years after they became obsolete :))

I repacked my bearings today, and everything looked shiny and new. I didn't have to replace even a single ball. Thanks very much to the forum and everyone who gave advice in this thread last Fall, especially FB.

I've got a new problem now (chainring wobble), but I guess I should post that in a new thread with a new title.