migrantwing

I had added this query to an earlier post, but it seems to have gone unnoticed so will ask here:

Would it be possible to change out the radial cartridge bearings/deep groove of my wheel hubs and swap them for angular contact bearings of the same size?

joejack951

What do you expect to gain?

I haven't spent tons of time searching bearing catalogs but I suspect that you'll have trouble finding the same size bearing in the other style.

FBinNY 

Assuming you can otherwise match the bearing, yes you can, but there are implications.

An angular bearing converts some of the radial load to an axial load. That's fine on a classic hub where cones thread onto the axle and can resist axial loads. However many radial bearing hubs lack this kind of positive resistance to axial loads and the hubs will tend to loosen. Angular bearings also need more precise micro-adjustment of the kind that threaded cones can provide. Without that it's strictly a nogo.

That said, I echo Joe's question ----why?

fietsbob

And (following on from FB )some hub designs wont work with anything But Radial contact bearings..

My Bullseye Hubs are an example . a 6001 bearing, I just dropped in an Enduro Replacement.
a 90% fill, all Balls in the race , Bearing..


https://img.alibaba.com/img/pb/843/58...web12_1084.jpg

https://wheelsmfg.com/enduro-6001-max...d-bearing.html

miamijim

Correct me if I'm wrong but 6001 refers to a bearings dimensions. 6001's are available in either Radial and Angular designs.

FBinNY 

You're not wrong, but you missed the point. The hub's design - specifically the axle must be compatible with the requirements of angular vs. radial bearings. Most radial bearing hub systems aren't.

WizardOfBoz

I think the 6000 series are for deep groove radial bearings. A 7000 series designation is used for single row A/C bearings, and 3000 for double row a/c bearings. There may be some dimensional matches between a 6000 and a 7000.

fietsbob

There are code additions to dimensional size standards for seal vs shield and all that .
Look at industrial Bearing supplier websites for more Information.

DOS

Kimmo 

Many radial bearing hubs develop a little bit of slop in the bearings. If your hub can adjust preload, this can be fixed, and AC bearings work a lot better with that (preload adjustment with radial bearings is a nasty kludge).

fietsbob

Depends on Hub Design.. un stated ..



roger durham, designed bullseye hubs, around a radial contact bearing ..
axle has 3 sleeves over it, 2 ends , and one between the bearings,
(+ shim washers)
tighten the QR, compresses the inner race ring, in the stack of sleeves
bearing balls themselves see no angular load,,

run out at the rim is not a significant amount..






...

FBinNY 

Two points to consider.

1- you absolutely cannot mix angular and radial bearings on the same axle. Angular contact bearings require a thrust load to maintain contact, and the reaction forces would be harmful to a radial bearing which isn't intended to handle significant thrust forces.

2- Angular bearings require micrometer adjustment to establish proper preload and zero play contact. Many (most?) hubs using radial bearings lack that kind of precise adjustment capability, and likewise cannot be set for an axial preload.

From a practical standpoint, there's no benefit to angular contact bearings other than the fact that hubs designed for them have the precision adjustability (beause they have to), while many hubs designed around radial bearings lack it. OTOH - if your hub has that level of adjustability, then you can use it to eliminate any play on the existing bearings, so a change isn't necessary.

FWIW - the most significant rational for choosing angular vs. radial bearings in bicycle hubs relates to design and manufacture, and not to function Angular contact was the logical choice for years because they made sense when using threaded axles. The user fine tuning that design offers frees the maker from manufacturing to precise tolerances. It's a rude/crude design, easy to produce, and easy to maintain, and has served for over a century. Radial bearings require close tolerance manufacturing, unless some user adjustability is provided. With modern manufactucturing methods, the required precision isn't a problem, freeing the maker to use radial bearings, and saving the costs and weight that the angular contact designs imply.

HillRider

Wow, I saw this and had to check the posting date to be sure it wasn't from a long time ago. Welcome back Francis, I hope this means you are going to be a contributor here again. We've missed you

FBinNY 

Thanks for the compliment, but while I may post again, I doubt it'll ever be to the same extent as in the past.

The fact is that I don't visit the site often, and only responded because the "you were quoted" email, brought the thread to my attention.

DOS

Thanks

I posed this question to my wheel builder, Jude at Sugar, and here is what she said about using AC bearings with my White T11 hub:

Yes, it would be ideal to have angular contact bearings as the outermost bearings in the hub. White Industries doesn't do this as a stock option because it's a lot of bearings for them to manage in inventory. But, as we replace bearings here, we use angular contact bearings which will require an adjustment.

Then I asked about the preload issue and her response was:

The locking collar on the non-drive side is actually an adjusting collar. So you'll lock down the collar just until the play disappears which is much like doing the bearing adjustment but you will have to be aware of any play in your wheel.

So I guess its possible but not clear why its ideal on the outermost bearings.

Andrew R Stewart 

Because it's easier to access the bearings for adjusting purposes if they are the outer set. Andy

FBinNY 

To add, it's likely impossible to adjust any non-outer bearing, so angular contact on an inner bearing is a no-no. Even if it were possible to adjust an inner bearing, the odds of getting any more than the outer pair properly adjusted are astronomical. Think about Newon's 3rd law. The preload on any single pair will always be equal, but if more than two are involved there's no assurance that all the bearings will be equally loaded.

In any case, you're greatly overthinking this. The question you need to ask yourself is what advantage do you hope to achieve with angular contact bearings. Without a material reason to try to out think the designers at White,there's no reason to assume that there's anything to gain.

Kimmo 

If you're adjusting preload on radial bearings, this is what's happening. As I said, it's a nasty kludge. If your cartridge bearing hub has preload adjustment, IMO the bearings should be AC.

Consider the angle between contact points on the races on a sloppy radial bearing that's had the rattle adjusted out. It's nasty.

DOS

Kimmo 

Proper loose balls is one of the main reasons I like Shimano hubs so much. Adjusted right and cleaned and regreased as necessary, they last practically forever. Cartridge bearings don't handle contamination at all.

FBinNY 

As I said earlier, the best choice of bearing type is a design consideration. The specific design details determine which bearing is called for, and the choice of bearing type will drive various design choices.

The claim that the radial bearings don't handle thrust (axial) loads well is correct, but immaterial because there's no inherent thrust loads in this application except for (possibly) those created by poor tolerances and/or user adjustment errors. For example, many users misunderstand the oft repeated claims of the need to preload, and adjust accordingly, not understanding that that advice is specific to angular contact bearings and does not apply to radial bearings.

I agree that you're seeing poor service life and should do better, but without knowing exactly why, it's impossible to advise about improving it. If this is a 3 or four bearing design, it's very possible that it' your adjustment, though it could be that there's a tolerance or bearing location issue, causing one bearing to have a thrust load because of the positions of the other 3. Or, there may be a dropout alignment issue, flexing the axle and overloading a single bearing.



FWIW - the type of radial bearing used by most hub makers is the same as used in electric motors where service life is near infinite (tens or hundreds of thousands of hours).

DOS

Kimmo 

Most issues with cartridge bearings on bikes are due to contamination. Usually not much of a consideration for electric motors.

DOS

63rickert

If bearings wear out as quickly as DOS states there is an evident design problem. I don't have any knowledge of current Shimano hubs. The longevity champ remains Maxicar hubs with shielded annular bearings. Most who ever serviced those did so only to see what was inside that lasted so darn long. 100,000 miles was normal. Spoke holes lasted that long too. They were heavy. Sanshin Gyromasters and most of the proprietary versions of that hub gave very good life with simple bearing replacement. I am now riding a 1960 version of Sanshin, no idea how many original miles, I've done 5000 and the bearings remain very smooth. Maxicar and Sanshin were freewheel hubs, both had axles with a reinforced section that ended the possibility of axle breakage. These are very old engineering issues. Expensive modern hubs should work.