Cup/cone to Sealed Bearing Conversion
 

Has anybody attempted to remove the cups from a hub and replace with a sealed cartridge bearing?
I have a Shimano Deore XT hub with a bad cup. Removing the cups is no big deal.
Seems like a 26mm x 9mm x 8mmw sealed bearing (629 RS)would press in just about fine.
Those are a deep-groove bearing. I have not as of yet found affordable angular contact bearings in that size.
I could just reuse the axle and locknuts, adding spacers to get 100mm OLN and go from there.
Would I need an internal spacer to prevent too much side loading?
Any thoughts? (preferably useful thoughts..........the "you're crazy" is a given)

Why not try to find the parts you need to use the cup/cone setup again. I personally think the cup and cone, especially Shimano's are the best around. They are easy to maintain, and when maintained correctly last forever.

I would do that, if I could find a source for the cups.
Can you recommend one??

Rebuild the wheels around a sealed bearing Hub. its simpler that way..


If you want to try it , seek out angular contact sealed bearings instead of radial contact.

Cup and Cone are an angular contact type arrangement.

where you find the threaded part to hold the bearing ID,
onto the axle is the chore you have to sort out.

Machine shop .. a Lathe and the right tap will allow ones to be made.

I tend to seek repair parts, for mass market parts, through Bike shops, first.

Regarding the internal spacer, if you do use cartridge bearings (the correct term for what you're hoping to fit - cup and cone bearings can also be "sealed") you will need something to prevent whatever locknut you use from pressing the inner race of the bearings towards the inside of the hub. Most cartridge bearing hubs have shoulders machined onto the axle for that, but you can also use a spacer tube like the ones in the BMX press-fit BBs I work on. A piece of aluminium tubing in an appropriate diameter would do the job.

I've never found a supplier for new cups for Shimano hubs. I have considered replacing with cartridge bearings, but a few things would stop me.
a) where would one find the internal threaded axle sleeve and nut?
b) what about the dust covers?
c) how would we deal with freehub bodies?

In the end, I could never source a complete set of parts for any hubs I had. So it was easier to rebuild wheels with new hubs/spokes which are easily available.

Replace the shimano hub and take better care of it. With proper maintainance the hub should be alive past your due date.

At least consider stepping up to better wheels. bk

Yup. As I said, I have not located any affordable angular contact cartridge bearings in the required dimensions.

The hub was acquired in its current condition, but, thanks for the tip.

The very nomenclature I used in my initial post.

Ah, but your title refers to "sealed" bearings, and it set my engineering OCD off :thumb: Apologies if it sounded harsh.

I do not think you can find them new, as others have mentioned. You might be able to go to a good local shop that has spare parts around then they may have a hub that has other issues but has good cups/cones. Just go in a ask, you never know.

I received a wheel on a used bike that had this conversion done to the rear parallax hub, and it was a disaster, unusable.

Nuke-Proof used to adapt a Shimano freehub body to use a cartridge bearing. I'm not sure what in the way of machining was involved, but they used a threadless axle.
You didn't mention what hub you have, but many hubs would not have room inside the shell for the added OD of a sleeve.
And you wouldn't want a cartridge bearing's inner race resting on top of the axle threads, that's for sure.

Also, if one side is converted to a radial-groove ball bearing, it couldn't be paired with the original angular contact bearing on the other end of the axle without immediate bearing damage under load.

This project would involve a lot more work than would replacing the hub, with no discernable advantage.

This is pretty doable. I don't like the idea of supporting a bearing directly on a threaded axle, since the thread peaks could mash making a sloppy fit.

Maybe you could add some epoxy filler in the critical area to make a better bearing seat. When SunTour made the cartridge bearing hubs I still use, they made a threaded part analogous to a cone, which was a 12mm baring carrier, properly toleranced for a solid.

No center support is needed, but you need to be aware that radial bearings don't want a preload. Instead be careful to bring in the locknuts only enough to take up any axial play. Ideally you want some kind of system so the locknuts (in name only) don't move after they're set. Possibly a nylon paint on the threads is enough, so you don't need a true locknut.

Good luck with the project.

dddd: the hub is a Deore XT front HB-M750

FBinNY: Thanks for the input. Maybe the better bearing would be a 26x10x8.
That would permit the use of a full-length sleeve that could be 12mm or so OD
reduced to 10mm (a thou or 2 less for clearence, for the engineers out there)
with a 9mm ID. That would permit use of a standard threaded axle w/ locknuts and
avoid preload.
I am successfully using a Ritchey front hub designed for a "Skraxle) which was a 9mm skewer/axle all in one,
but using a 9mm threaded front axle w/QR and conical springs. It is a similar configuration.
More work, I know, but I love to tinker.
Who knows, maybe a kit could be marketed??

As for angular contact cartridge bearings, I understand the need for such in theory.
I will check some sealed cartridge bearing hubs to see if they employ angular contact units.
Those that I have found are close to $100.00/ea and up.

I have replaced the rear non-drive bearing of a Dura-Ace hub with a cartridge. I think the replacement was a 6001-RS; anyway it fit perfectly. And it functioned perfectly. Of course, I needed a threaded sleeve to support the bearing (12mm I.D.) on the 10mm threaded axle. I also needed some spacers and a dust cap that was spaced about 2mm outside of the cartridge to provide an additional layer of protection. Cartridge bearings are in fact very poorly 'sealed' for bicycle use, so you need to create a second labrynth seal to keep the worst of the water and dirt out.

Keep in mind that the cup dimensions of XTR and Dura-Ace hubs are different than anything else in the Shimano lineup. You have to measure...

And don't put too much side preload on the cartridge - the standard 6001 bearing can take a certain amount of preload, but don't overdo it.

On decent Shimano hubs I have also replaced the ball cups. I had another Shimano hub with the same dimensions; I scavenged this for the cups, balls and cones. You need to rig out a cup extractor, and some way of immobilizing the hub shell while you hammer away during the extraction. And then a bearing press to push the new cup in. This is the better solution, as Shimano's hub design is superior in every way to any hub that uses cartridges.