I'm specifically referring to things like this: https://www.skf.com/group/products/be...ngs/index.html

Would those type of bearings provide any sort of advantages for bicycles?

Not really. The angular contact bearings traditional to bikes are forgiving of the slight misalignment that may occur on some bike parts. And those components that used paired commercial (cartridge.aka sealed) bearings are usually built accurately enough to work fine with traditional bearings.

Are angular contact bearings the ideal sort for bikes then?

Ideal is a good way to start a debate. The beauty of the old fashioned cup/cone angular bearings is that they're forgiving of imperfect manufacturing,tolerate abuse, and are very field serviceable.

Radial contact bearings are also excellent, but call for closer manufacturing tolerances.

It isn't a matter of better or worse in an absolute sense, but choosing a bearing appropriate to the design, and manufacturing precess of each component.

If you go back to that skf catalog you'll find all manner of bearings, including many specialized designs made to address all kinds of unique situations. None are better or worse, just different.

That is a good point! I did not mean to start a debate! lol

I guess a better way to put it is with two questions:

1) What is the norm for current manufactured bikes?

2) Ignoring serviceability, which is more efficient?

Hoo boy...

[QUOTE=krfkeith;15597065]That is a good point! I did not mean to start a debate! lol

I guess a better way to put it is with two questions:

1) What is the norm for current manufactured bikes?[quote]
Most parts are designed with thrust surfaces for lateral location, thus obviating the need for self-aligning or angular contact. The tolerance-range used tend to be in the middle-range as well. Larger-clearances aren't needed as for high-RPM motors. Nor tight-clearances with thick grease for high-load applications.

The only bearing actually needing angular-bearings would be the headsets. However, the best bearings used here are roller-bearings for high-loads. Stronglight headsets with their roller-bearings tend to last 10x longer than the ball-bearing models. Along with replaceable bearing-races makes it a great design in headsets. Several decades later when manufacturers went to integrated headsets, they used a design very similar to the Stronglight.

Pretty much all usages of bearings incorporate two widely-space bearings. Traditionally cup & cone bearings were used. When upgraded to cartridge-bearings, the dual-bearing designs pretty much guarantees the shafts are always perpendicular to the bearing surfaces. You simply cannot shove the shaft out the 2nd bearing if it was out of alignment.

So needle bearings are good for the headset? I guess that makes sense, I never thought about that.

Norm depends on price range. There are exceptions, but basically the cheaper the bike, the more likely you are to encounter traditional cup & cone bearings. Higher price tends to bring more cartridge bearings with it.

Efficient is tricky. Cup & cone are more forgiving for production spread. Takes longer to assemble but you can use crappier stuff.
Cartridge bearings are faster to install, but you have to run production at tight tolerances.
A factory with good machines and high salaries would want to use cartridge bearings. Low salaries and poor machines, go for C & C.
Brand new cartridge bearings can have comparably high seal drag compared to cup & cone designs.
The big thing is that bearing drag is such a tiny proportion of overall drag to make the question entirely academic apart from the most extreme and clear-cut racing applications.

Serviceability is also a so-so thing. Sure, C & C can be disassembled, cleaned and relubed. That's fine as long as you aren't getting pitting and grooving. Those things can be definite showstoppers.
Cartridge, then it's a replacement job. Different designs reach different levels of user friendliness, but as long as I have the spares available, I reckon swapping bearings in my one cartridge bearing wheelset is about a 10-minute process.
But of course I'd find some reason to touch up spoke tension, clean & relube the pawls and whatnot while I'm still in there, which'd extend the process....

Ha ha. Everything was going along fine, and then up pops the word "efficient"

What's most efficient is riding instead of spending time on something that is a few hundredths of a percent contributor to drag on a bike.

I understand what you are saying, but don't you think responding in that manner was a little needlessly glib? I'm new to bicycles/cycling, but I find mechanics and mechanical engineering sorts of things very interesting in their own right. Moreover, I don't really think discussing theoretical questions and riding bicycles are mutually exclusive, it isn't a zero-sum game.

I suspect that you're getting facetious answers because you've asked an unanswerable question. There's no one superior, or more efficient bearing, except to say that ball bearings are better than plain bearings (or bushings). The key is suitability of the particular design and application, then quality of execution and finally and in reality most important quality of maintenance.

There are also some tricky, counter-intuitive decisions, for example most lubricants are chosen to maximize service life, not necessarily for least drag, so good maintenance usually comes at the expense of efficiency.

In any case, from best to worst case, the differences are so tiny compared to wind drag, and tire rolling resistance. Something like correct tire pressure has a far greater effect on efficiency than improved bearings.

In any case the so called "best" debate remains up in the air. Among top quality hubs, some have user serviceable angular contact bearings, and others have commercial bearings, mostly radial, and some angular. To date no one has demonstrated that there's a best among the best.

BTW- as a newbie (here) you need to know that your question isn't new, and for most of us there's a been there, done that sense to it. We're a bit jaded and tired of endless meaningless discussion about some niggly fine point that's already been discussed ad nauseum. Rather than be offended, or justify your question as worthy of discussion, you might take some time to do some research, here on the forum, or on the internet in general.

Speaking for myself, (I only ever speak for myself) I'm always willing to help someone who needs it, but much less willing to try to satisfy someones intellectual curiosity on some minor issue when there's already enough info, if he'll just make the effort to look.

Conic needle bearings for headsets were better , though the stronglight ones were made for the puropse.
and assemble on the bike, not a sealed cartridge , Delta version added the O rings to the aluminum parts.
and are much flatter a cone, than the roller bearings used in automotive application.


Efficient for What? state the Goal ..

As noted, there certainly are exceptions. All of Shimano's hubs, including Dura Ace, and all of Campy's individually available hubs (limited to Record these days) use cup and cone bearings and these certainly aren't cheap or cheaply made.

I do understand what you mean. I asked the original question because I couldn't really find anything on it specifically. I understand there is no one, single answer. Like I said, I asked more out of a desire to clarify. It's easier for me to tackle a project if I understand all the different options one has, and what the effects of these are.

I have done a little bit of research, and I didn't mean to try and suggest my question was unequivocally a worthwhile one. I don't doubt that there is a mostly negligible difference. I only asked because it's hard to find conclusive answers.

You didn't find conclusive answers for the simple reason that that aren't any. Once you get to a decent quality lever, it's more like a Coke vs. Pepsi debate, with a few Dr. Pepper fans to keep it interesting.

You speak of a project. If so, start by defining the needs and prioritizing them. Then factor cost and your capabilities maker an outline and that will point you toward the right answer (for you).

I finally clicked the link and went in for a look. The line about being tolerant of shaft deflection and mis-alignment tell me there would not be an application on a bike I can think of. I think it's intended more for high load applications where the outer ends of the shaft are supported by the bearings and maybe a two ton roll of paper loaded on the shaft.

No, because they don't solve the problem on a road bike. Fretting damages the races. Read and learn grasshopper. https://draco.nac.uci.edu/rbfaq/FAQ/8f.13.html

In regards to the bushing comment. High quality bronze bushings would be more than adequate for our use. A bike wheel is turning about 670 rpm at 60 mph and a track racer may hit a cadence of 200 rpm. Rolling resistance of our tires are more of a factor than the bearings.

And at moderate-to-high speed, aero drag is the dominant force holding the rider back. One of the folks on the recumbents.com forum tested several wheels with a power meter to see which was fastest. The "winner" was a very cheap, ordinary wheel with wheel covers fairing in the spokes.

It's fun to build up a really high quality hub and spin it in your hands to feel the smoothness of the bearings. Whether this translates to real-world improvements in "efficiency", well

While they don't solve the problem, they extend the service-life of the headset by over 10x over ball-bearings. And the races are replaceable, so at that 10x longer service-interval, you just replace the lower bearing-race rather than the entire headset.

To give the OP more data on efficiency and following up on some other's post, here is where rider's energy is expended on a bike at various speeds:

Note that bearing and tyre-drag represents a smaller and smaller percentage of total-drag as speeds increase. That's because drivetrain-drag goes up linearly with speed while wind-resistance goes up to the square-power of speed and the power-required to overcome that wind-resistance goes up by the cube-power of speed. In order to go twice as fast, you need 8x the power to overcome the extra wind-resistance.

Most effective way to improve your power-output's efficiency is to combat total aero-drag: A*cD. With traditional bikes, one can improve A*cD by tucking in as low as possible. Even with trained cyclists, there's some loss of power-output, but is more than made up by the reduction in aero-drag. You can get even better reduction in A with recumbents, and total-drag can be only 50% of an upright bike. Once you've minimized your A as much as possible, you start playing with cD by using fairings. These aero mods will increase your speed for the same power much more than any improvement in drivetrain-drag.