Sealed bottom bracket longevity
 

Question, curious more than anything.

Would you trust a NOS sealed BB that sat on a shelf for the last 30 years? I honestly don't have a ton of experience with sealed stuff so I really don't know if the lubricant inside would hold up longer over time.

Specifically, one of the F.A.G. brand BBs, if you need technical details, see: http://www.schaeffler.com/remotemedi...14_5_de_en.pdf

Yes.

I have a Phil Wood BB that I bought in 1975. It's been in 4-5 bikes and still works great! I also have a Shimano UN72 BB cartridge that I've been using on an off road bike since 1992...

Two problems can happen: seal failure and grease deterioration.

verktyg :50:

Chas.

francophile, The sitting on a shelf part would have me a bit worried. I have a Shimano sealed BB, non UN designation, that is OEM in my '95 touring bike and I trust it.

Brad

German mechanical engineering? They usually know what they're doing, as long as it doesn't involve the EPA.

Sealed unit, in a plastic bag, in a box. Limited chance for the elements to affect the metal or the lubricants, so long shelf life should be fine.

I have a pair of wheels with Suntour sealed bearings from, probably, the early 80s. I pulled the seals and found they were excellent with good grease. I smushed some new grease in just cuz I was there but they are doing great and sound-n-feel very smooth.

I now have an old wheel from, I'm told, a Viscount Lambert with sealed hubs. Someone may have an idea of how old these might be. I've pulled those seals and the grease is fine and the bearing are clean and smooth. I'm guessing that a sealed bearing can last a very long time.

However, as with anything, quality of a sealed bearing can vary all over the map. There's cheap ones that give up the ghost too soon and real good ones that last a very long time. Buyer beware.

The modern *** assembly I don't think was the same 30 years ago. The modern version has the races machined right into the spindle. Be interesting to see how they load the ball bearings into that, there must be a lateral trough somewhere.
Some grease lasts longer than others, but 30 years is a long time. Outside the planned chemical stability I would think.

I have two crunchy Phil bottom brackets I received with bikes I bought, one day I will send them in for new bearings.

Cartridge bearing manufacturers do specify shelf lives . Even modern synthetic greases as used in sealed cartridge bearing will eventually demulsify when stagnant for long periods. So, there is reason for concern. Regular use will keep the oil and carrier emulsified, so active bearings can have a very long lifespan and outlive stagnant bearings.

As others have mentioned, the old grease does degrade. Also, rubber seals will harden, turn brittle, shrink, and/or crack as the rubber ages. Tires actually have shelf lives too, for example.

This one sat on a shelf, unbagged, in a climate-controlled room, for an unknown period of time. It seems to spin fine, not crunchy or gummy (low resistance).

It sounds like the overall words to heed with sealed units are: With no crank attached, spin the spindle and assess whether things are smooth or gummy (should be obvious, eh?) and if gummy, move right along?

Thanks as always for the feedback.

So, dumb question: I've got a couple of spare Shimano cartridge BBs in boxes since I hate being without a replacement part when I need one -- should I twist them once a year, or every couple of years, or is it really only a concern if a part goes unused for 20 years? :)

Mostly 70's vintage. They are press-fit and replacements are a standard size and available & fairly inexpensive.

The nice thing about cartridge bearing BBs is that they don't take a lot of work. Use them until they fail, then replace them. What's the worst that could happen? If you bring your bike home at night, you'll be fine, especially if you have a spare. I guess I wouldn't put this unit in and take a month-long tour, but you're not doing that, are you?

Oh, the VW engineers knew what they were doing all right... they just happened to choose an unethical objective. :rolleyes:

As a guideline, SKF specifies a shelf life of three years for their sealed bearings. I imagine other manufacturers' shelf lives are similar. Consequently, I'd be exercising the bearings to stir up the grease at intervals no longer than that, to ensure you get maximum life expectancy.

I have a NASHBAR integrated cartridge BB in my Cannondale installed 5yrs ago and is working quite reliably.

That sounds perfectly reasonable. Thanks, T-Mar! :thumb:

Not really,.......Biggest piece of junk I ever bought in my life was my 1997 Passat GLX VR6....
It was reliable for exactly 276 miles.... then the first big thing broke.....ECU, fried, left me stranded on the freeway at rush hour traffic....which gives anyone the idea on how the next 70K miles went.....
Sorry any VW fans out there, the truth just have to be told about German engineering....:rolleyes:
Only German engineered thing I own and trust enough these days is my Braun shaver.... but dang, the head still manages to snag my mustache if I'm not careful....Owwie!!:rolleyes::D

I've got over 307,000 miles on my 1991 Mercedes Benz 560SEL.

Granted, it's not perfect. The self-leveling hydraulic rear suspension is dead, the front passenger side window needs manual assistance to go all the way up, the sun roof has decided it doesn't care to open anymore, a speed hump ate holes in the spare wheel well of the trunk earlier this year, and it has hail dents all over, but at least the A/C still works. :thumb:

Thing to remember is that German engineering is mostly great, but Germans are still human beings capable of making mistakes.

Attachment 529046

If the grease feels fine, it probably is ok.

The BB in my PX10 probably hadn't been touched since the early 70s. It felt horrible, but when I pulled it, the bearing and races were perfect, but the campy grease was the consistency of parmesan.

I vaguely remember those BB from my bike shop days - frankly mostly for the jokes as you might imagine. You might be able to put fresh grease in them - I can't remember.

The cartridge bearing on my fatbike lasted 550 miles on the beach. The GXP BB bearings (sealed type) have lasted 1500 beach miles and are going strong (Quando hubs too). By beach I mean salt water beach of blacks sands with magnetite, titanium, iron, quartz, silica, and various granites and basalts ground to a lapidary paste.

This BB does not have cartridge bearings; it is the assembly which is sealed.
The plastic sleeves give me pause, as do many of the design details. But like anything for a BMX bike, if it works, and they price is right, lifespan isn't much of an issue. Definitely would not use it for an adult size fixe.