robertofergy

I just picked up a new(old) Sekine and I was cleaning out the bottom bracket but I found this weird tube in it.









Here it says OSAKA S.P.S TOKYO. It also says C.B.C on the top but my pic cut that off




Here its says PAT. NO. 55899


I assume its in there to keep things clean if debris falls from the seat post, but should I put this thing back in there after I repack the BB?

KtownDougie

Can't see the pics, but if it's an accordion-shaped or other plastic tube that just fits into the BB, it keeps crud out of the BB. Yes, put it back.

robertofergy

Sorry, first time using an image host to post pics. Should be good now.

old's'cool

I can see the pics and yes, KtownDougie is correct.

robertofergy

K, thanks guys. I guess ill put it back afterwards.

KtownDougie

Yep, thought so :-) I found one of those when I tore apart a '76 Nishiki Custom Sport. I meant to use it in my '74 Favorit, but I was in a hurry to assemble it and I forgot

ilikebikes

It serves a purpose! So clean it all up and put everything back where you found it. ;0)

auchencrow

I think they do more to direct slag and crud into the bearings than not having one at all.
-And since I don't reuse old bearing retainers, I don't want it butting against the shiny new ball bearings. JMHO.

rothenfield1

^^^
I don't have a strong opinion about whether to keep or ditch the bearing retainer, but the one mechanic that I have come to trust on the subject agrees with you that it is unnecessary. Also, If this is your first BB overhaul, it is easier to keep the caged bearings. But; eventually, you may find that it is better to let your balls hang-free. Sorry Ladies. Oh No!

stronglight

The plastic sleeves just block any falling rust or crud which may rattle loose inside your frame tubing. By the 1970s Campagnolo, Stronglight, Suntour, Shimano and most other manufacturers were supplying these with their cranksets and bottom brackets. The "accordion" bands on that one would allow it to fit many different bottom bracket widths and cup sets. They even came with Campagnolo Record and Shimano Dura-Ace bottom brackets until sealed cartridge bearings gradually began to replace loose ball BB cup sets during the 1990s. I'd clean it and keep it.

The metal ball retainers on the other hand were a convenience item intended for faster BB assembly in a factory or maintenance at a bike shop. Less chance of anyone losing loose balls or installing an incorrect number. To be honest, retainers really do make assembly of headsets with as many as 50 tiny ball bearings MUCH easier and far less messy. But, they were always far from creating any sort of sealed cartridge bearing smoothness by simply spacing the balls evenly apart. If you plan to re-use those same ball bearings, be sure to thoroughly clean all the grease from the retainers and inspect the individual balls for any wear or damage.

Be sure to place the retainers back in the cups with the correct orientation. Since most retainers now found on older bikes were later generic replacement parts, the cages can often scrape against the cups if they are not set back in place facing the right way.

Road Fan

Depends - if you have a vintage Masi or something else with a big cutout in the bottom of the BB, a lot of crud thrown up from the front wheel can be thrown into the bearings. I found the Campy sleeve with a Campy BB reduced crud problems on my Masi. I don't know if any others have any degree of effectiveness.

Some French bikes had a wine cork stuffed into the seat tube. I think one benefit of that was to prevent dirt from falling down from the top of the seat tube into the BB area. Perhaps the BB sleeve helps with that as well.

Grand Bois

You really believe that?

Lenton58 

Just my opinion on BB sleeves: I would not put a BB in without such a tube. And if I could not readily get one, I'd make one. In my experience, V&C steel frames can often produce more slag and crud, even though you were sure that you scrubbed it all out at the beginning of the build. And you can predict where gravity will deposit it. And if the BB has a cut-out, you really do wanna have one. Back in the days before sealed bearings, champion team racers had mechanics tearing these machines down and reassembling them more regularly than most of us are doing. Then it may have been no big deal leaving them out. And by the way, I don't believe ... or rather, I have not found them to be butting up against the bearings. I feared that they might and was ready to ditch the tube if that were the case, but so far they haven't.

Bearings: All things considered they are cheap as borscht, unless you have to order some special size campy wheel bearings! So for BB's, throw the retained bearings or old loose ones in the recycle scrap bin and install fresh loose ones every time you overhaul. According to my research, and against my prior assumption, bearings do not just go around and around. They wear eccentrically. So IMHO, if you had to reuse them, at the very least you would want to put them back on the same side.

I buy bags of Dura Ace bearings which are top grade for roundness and hardness. And by buying from the same shelf, you can be reasonably sure that they were all from the same production run. The results are buttery smoothness on otherwise well-used spindles and cups.

auchencrow

Absolutely.

(With the exception of a wide-open Masi bb noted above.)

From what I have personally witnessed, the dirt does not stay in the accordion pleats: Rather, it is directed away from the middle of the bb shell (where it would do no harm) and ends up nearer the outer ends of the tube. -(As shown in the last pic above, with the rusty-looking ends!)

So - instead of a plastic sleeve, I typically apply a little extra grease on the inside-bottom face of the bb shell: I don't have any data or photos to prove it, but intuitively, I would think this could help more to prevent outward migration of particles toward the cups. I also endorse the idea of plugging the seat tube if it is one with an open end.

- Either way, with or without accordion tubes, I don't think it makes a huge difference: It is much more important to replace and re-pack the bb bearings, which people rarely do, based on the many bikes I've purchased.

sekaijin

I recently homemade a BB sleeve for the first time, for my current winter project.

But wow, I had no idea there was such fierce controversy around this topic.

Hope this was worth doing ... my BB is installed and my preferred next time to open it up (just like you say, auchencrow) is NEVER!

Chris_in_Miami

While I agree that the shield is not much help, you could also grease the outside of the pleats and let them act as a dirt trap. I don't think the dirt on the ends of the OP's shield got there by migrating outward from the center, it looks more like stains from dirty grease that was thrown from the bearings.

Apart from that, I don't have a strong opinion about them either way

SJX426 

Is there a source for new Campagnolo sleeves?

Grand Bois

And you also believe that there's any chance that the sleeve will contact the bearing balls? Take a good look at the picture in #1.


Do they really have to be genuine Campagnolo? Who will know?

auchencrow

Picture #1 has a bearing retainer.

Old Fat Guy

Makes no difference. When the cups are tightened, the sleeve is compressed by the cups, it comes nowhere near the ball bearings.

Do you really think that the manufacturer would go to the added expense and installation hassle of a sleeve if it weren't necessary?

Grand Bois

It also clearly shows that the sleeve stops near the inside edge of the cups. It doesn't get anywhere near the bearings whether a retainer is used or not.

OFG is quicker than me.

Old Fat Guy

Probably faster on a bike, too

auchencrow

10-4. I was wrong about this aspect.
Still, they're always clear in the middle and contaminated at the ends, so I don't think they are directing the dirt where I would like.

treebound 

We won't talk about the first BB I regreased a long time ago. Stuff that tube full of grease figuring that's what it was for. Afterall I'd seen grease zerts on housings and headtubes and figured that pumping in grease would fill the tube, so therefore the tube must be filled. Made sense at the time, but I only did it once.

Now if I find one I clean and reinstall it, if there isn't one in there then I don't worry about it.

As to plugging the seat tube? I've torn down bikes where the seat tube was full of water. After seeing that a few too many times I tend to leave things open and like to see a drain hole.

auchencrow

Agreed - but I think a cork in the top of an open-ended seat post to keep the water out would be a good thing.