John E

Best of both worlds -- full-complement caged bearings. Sounds like a winner all around.

rootboy 

Awww, but that's too easy. Then whad'a we going to talk about? What kind of grease to slather those bearings in ?

smontanaro 

Don't get started on grease. I'm not about to open things back up just yet.

Moe Zhoost

What documentation can you provide to validate these statements?

jethin

Maybe, but I assume he’s in the business of selling caged bearings for industrial applications.

“Applications with extremely light loads, for which the friction introduced by ball cages can present issues.” — Note “friction introduced by ball cages.” Also wouldn’t “light loads” include most/all bicycle applications? If they’re superior why wouldn’t hubs used caged bearings too?

SamSpade1941 

What documentation can you provide that loose balls are superior .. my guess none but I’m willing to be convinced other wise.

SamSpade1941 

Actually he’s in the business of building precision manufacturing equipment that uses caged bearings as part of their assembly. As far as the friction you’re referring to in those light load applications . I will concede that a bicycle is a light load application, but I would ask that you prove to me you can feel or measure a difference between a headset or bottom bracket with cages vs loose balls . I’m willing to bet you can’t.

Again if you like using loose bearings because it makes you feel good treat yourself. I’ve read a lot of these arguments it always comes down to feelings not facts. I will stick with the option that retains lubricant better .

jethin

And likewise you can’t prove that caged bearings in bicycles are “superior.”

Do you use a precision tool to adjust your hubs, or is good old fashioned feel good enough? I do believe that loose bearings feel a bit smoother, but I’m willing to concede that I might be crazy. But on this forum I know I’m not alone in such peculiarities.

Thanks, I’ll continue to do as I please, and you have my permission to do the same.

63rickert

Bicycles are not light load applications. Stand a 200# rider on a 6-3/4" crank arm and that is a lot of torque. At super low rpm, which is worst case for maintaining lubrication. Add in that everything on a bike is underbuilt and nothing remains in alignment. If it ever was in alignment.

Bandera

Let's ask Sheldon & Jobst if those angels dancing on the heads of pins are wearing ballet slippers or tap shoes.....
Same irrelevance regarding "performance" as the "caged vs loose" bearings in a bicycle BB, but Seraphim in tap shoes gets my vote for a Bugsby Berkeley version of heaven.


-Bandera

SamSpade1941 

You have a point and one I did not think about . A bicycle could indeed be considered a heavy load applicAtion especially when I’m on it

jethin

If you say so, but I’d still like to see the engineering specs. I still believe bikes are relatively light load compared to industrial applications. Anyway I don’t really care all that much, so I’m gonna to go for a ride.

Moe Zhoost

I made no statement to validate. Nor do I have a strong opinion about the topic one way or another. Had I posted an opinion, though, I would have wanted to be able to back it up. I asked for documentation specifically because I like to learn all I can about the engineering and technical aspects of bicycles.

Archibald Sharp, in his book "Bicycles and Tricycles - An Elementary Treatise on Their Design and Construction", has a great discussion related to bearing friction due to mutual rubbing of the balls. This book is a bit dated (1896) but shows that this question was being discussed very early in the modern bike era. His bottom line is that caged or uncaged, the friction due to ball-to-ball or ball-to-cage was minimal. He did mention that cages were quickly abandoned in manufacture specifically because a less balls could be put in the bearing rendering it less reliable than uncaged. He points out that wear on well adjusted and lubed bearing balls, caged or not, is not significant.

Personally, I usually use caged balls, but when replacing balls will sometimes opt for loose when I don't feel like cleaning and refilling the cages. I often use loose balls for headsets because I think it helps avoid indexing, but also because I love the challenge of getting everything together with so many small items that go easily astray.

clubman 

My wife took tap dancing lessons once. Once.

As someone who once repaired trains for a living, a 300 ton freight car would run on 4 axles, a total of 8 plain bearings. Each 'journal bearing' was simply a piece of brass babbitt sitting on polished steel, with oil wicked out from a bath into the bearing via fibrous cloth. After 200 years, they were finally phased out for roller bearings but still, pretty amazing.

There you go, you all learned something new today!

d_dutchison

@SamSpade1941, Thanks for the interesting reply, and ensuing lively discussion.


While I believe the first 3 points that your authority lists are not a factor in a very low speed application like a bottom bracket, their last point about retaining grease certainly is, and one I hadn't considered. I've opened hundreds of BB's and finding a row of completely dry ball bearings running between two walls of grease is pretty common.

Add to this a point made later...

...and yes, I will concede that there is an advantage to using a precisely made set of full-count caged bearings in a bottom bracket.

Prowler 

I cannont argue the points made but, here's the rub: how do we find "quality caged ball bearings"? I can imagine that quality balls are easy but determining the quality of the cage ( given the variety of ways to cut costs and corners on a stamped, rolled n welded cage thing) is beyond me. I have no idea what the relative quality of that drawer full of caged bearings at my LBS is. As pointed out above, even wide tolerances in cage dimensions can alter performance consistency. Finish of the edges on the stamping can as well. Spacing, rolling of the cage 'fingers', cage height and OD. My head spins.

How to know what's what".........

Road Fan

I don't think torque is the issue for the bearings. I think the issues are bearing speed, radial contact pressure, and axial force, calculated in consideration of worst-case static misalignment (frame or BB shell not aligned or poorly bored/threaded/finished; poor tolerances) and dynamic misalignment (flexing of BB and chainset due to pedaling and road bump stresses).

And a clear industry criterion for "heavy," a definition of proper design margin versus life, and a good understanding of how the options in material properties figure in.

Then we can talk. I'd like to know how to margin BB design and impose a sealing/lubrication strategy that would give 30 years/100,000 miles in a utility bike like a classic roadster. Maintenance free, guaranteed durability.

63rickert

I'll respond to that. First off the number of consumers/owners/riders who will ever keep a bike 30 years, much less in service for 30 years, is trivial. The number of riders who will ever ride a bike 100,000 miles is trivial. The motivation for any manufacturer to design bikes to that standard is not there.

Torque is not so much the issue as are the consequences of torque. Let me give an example of dynamic misalignment as you call it. I have two bikes with bent steerers in the house at the moment and recently worked on a third. None of these bikes were in accidents. None of these bikes have bent frames. Two of the bikes have real complete histories known to me and have never been abused, never even had loose headsets. So how does a steerer take a permanent set into shape of a banana? Heaviest tube on a bike. Some want to dance angels on heads of pins and ponder whether headsets last longer w/caged or loose bearings and whether we should call dented head races fretted or brinelled. I look at short stout pieces of tube bent out of shape and wonder how riding a bike at all is possible. Once the steerer is bent the headset should be under impossible load. But two of three headsets from above bikes are still in use and show no evidence of wear.


It's not even possible to get owners or manufacturers to accept that a frame needs a drain or a vent to keep inside of frame dry. I read comments on this forum from supposed experts who say these things are not necessary because they have never seen a frame rust through. That's just one. No limit on that kind of nonsense. There are likely seven threads a week here where completely absurd claims are made about service life or durability. Same absurd claims are made about fragility of various parts and brands. Endless assertions that bicycles have fundamentally lousy brakes not suited for use in traffic. Keep that up and we can look forward to bikes being banned. Given that perception and reality just do not connect what is there to talk about?

Galileo described designed and drew bearing retainers. We are still arguing about this?

My wife rides a bike 44 years old that has way over 100,000 miles. Many original parts. Original bottom bracket, original headset. Campagnolo. Just saying Campagnolo gets a good many here upset and angry. Reason that bike and its parts are still going is she is very lightweight. Everyone has noticed that light riders get unusually long service from most anything. Which would tell me that parts just as they are and have been are really close to level of durability you want. Weighing twice as much seems to reduce service life orders of magnitude. I can't claim to understand that any more than I understand bent steerers. Weight n gives durability, n+1 cancels durability. Dunno.

63rickert

Another take. 100,000 miles on a utility bike is roughly 10,000 hours of service. Cranks went around about 40,000,000 times. Nothing is designed for that kind of service life. That is civil engineering. Bridges. Not mechanical engineering.

Road Fan

Well, as you know, neither of us is likely have another 50 years of pedaling. My main point is that if we are going to talk about "heavy load" et cetera, I want some solid concept. I know bearings aren't new, and I have read Sharp and Galileo. My point was not that we all need the kind of durability I stated, not did I say it is possible. It was that with good understanding of bearings from a technical point of view, we can talk about what it takes, and hence the benefit of cages or whatever other design feature. I don't see that understanding. I'm not a mechanical engineer. I am a Systems Engineer by role, and we are skilled at assessing the technical capability present in a discussion and whom to listen to, even in a crowd of many disciplines.

I don't know if your steer tube observations are related to BB bearings, but something surprisingly big is going on in those steer tubes. Could be 50+ years of Chicago riding has accumulated in your steer tube walls at the point where your quill stem ends, or another steer tube reinforcement ended. You might want to reinforce or even replace them. Point taken, old bearings can do a superb job of transferring force. Could some of it have been communicated through the BB? I suppose yes, since the BB translates side to side, rolls as that happens, and yaws due to chain reaction force pulses.

BFisher

While I agree that the motivation for those high manufacturing standards isn't there, it really should be. Manufacturing standards should be much, much higher than they are across the board. We waste too many resources producing disposable goods. Ever have your 6 year old washing machine crap out, only to discover that the machine, by design, cannot be rebuilt? How wasteful. But that's another conversation...

I also agree that so many seem to over think things to the point of absurdity at times. The truth is, most bicycle parts and systems in good condition are serviceable. They may take a certain degree of adaptation on the part of the rider, but they will work. We may prefer one over another, say for weight savings, strength, cost, aesthetics, etc., but the differences aren't usually quite as great as we make them out to be. Loads of riders get loads of miles out of bikes with bearing retainer cages, and never really think about it. Some still ride wood rims. Some use 50+ year old internal gear hubs. One of the nicest rides I ever took was a ten mile trip on a Schwinn Varsity with original brakes, alloy wheels, upright bars, and a 1x5 drivetrain that utilized a Shimano Eagle II derailleur. It worked way better than the internet says it should. I've got a 51 year old Fitchel & Sachs Torpedo Duomatic hub that still works like a Swiss watch. It has caged bearings. The headset on my old Raleigh had loose balls. Both are fine.

Now go ride your bikes!

jethin

I think it bears mentioning that frame of reference is important here. I’m coming at this from a performance perspective; others longevity, extreme conditions or just basic service. When it comes to marginal issues like this I think performance is the primary issue. If you just care that your cranks turn you could probably put pebbles in your bb.

Some folks here like to wax poetic about buttery smooth bearings. Some manufacturers tout their expensive bearing applications for when seconds count. Fact or fiction? We may never know. But my hands generally tell me that less metal / uncaged bearings feel smoother.

And hey, what would we do with ourselves without ridiculous, speculative discussions of minutiae like this?

Road Fan

Anybody wanna talk about chain lube now?

Road Fan

10k miles at 1 hour a day is 10000days, or 27.4 years, 10 miles a day.

Ok, it's not normal vehicle engineering.

I still don't want to talk about high loading or low loading without some kind of criterion.

bikemig 

I'm going to be disappointed if this thread doesn't make it to at least 5 pages,