Bicycle Mechanics - Questions about Suntour cartridge bearing hubs

I'm wondering about something I'll probably have to deal with at some point in the future. I'm building up an early '80's touring bike, and it has Suntour hubs with cartridge bearings (40 spoke rear freewheel hub, 36 spoke front). For now, the hubs spin as smooth as silk, but I've never worked on cartridge bearing hubs before, and I'm wanting to know what I'm in for if and when the bearings go bad. The bike is nearly twenty-five years old, I've just bought it, and I have no reason to think the bearings have ever been replaced. Like I said, for now the bearings seem fine, so my thinking is that I'll probably just ride it and see what happens. It's a touring bike, but unfortunately I've got no immediate long tours planned, the bike will be ridden mostly for city riding and some longer road rides.

The thing is, in looking at the available cartridge bearings in various catalogs, etc., I'm a little overwhelmed by the selection that's available. As far as the size of my bearings, they have an inside diameter of approx. 13mm, and an outside diameter of approx. 27mm. This was as close as I could get measuring with a metric ruler. In looking at the available bearings, it seems I may need to use calipers to get the precise dimensions, because the sizes are often listed in tenths of millimeters. And beyond the size, is there a certain type, brand, etc. that I'll need? There does appear to be some text and numbers on the plastic seals on my bearings, but it's not legible. Also, is it possible to carefully remove the plastic seal with something like the corner of a razor blade and simply flush the old grease out and re-grease the bearings, and then pop the seal back in? If that's possible, I could easily service the bearings with the cartridges still in the hubs.

And the other thing is how to get the cartridges out of the hubs if I have to replace them. I've removed oil seals from automotive axle housings with a seal puller, which works more or less like a larger version of a cartridge bearing puller. Do I need to get one of the bearing puller tools, or is there another way to pull the cartridges out? It seems that a properly sized socket could be used to tap new cartridges into place, so I'm not too worried about that part of it.

Any help is greatly appreciated-

You need a special tool to remove the bearings and I believe the bearing are standard size (ie you could pick them up at bike store or industrial supply store.)

You can use a nail longer than the width of the hub to remove the bearing. Place the nail head-first into the hub, resting it against the inner surface of the bearing. Tap on the point of the nail with a hammer, moving the nailhead periodically around the bearing.
Replacements can be found at loosescrews.com.

I had a set of wheels built up in the 80's with Suntour Sprint (?) cartridge bearing hubs. Didn't ride them enough to need to service them.....but, they had the same internals as some Specialized sealed bearing hubs I previously had on another bike. I replaced bearings on one hub (with simple tools from Specialized). Method above (Nick Burns) sounds about the same.

You need a special tool to remove the bearings and I believe the bearing are standard size (ie you could pick them up at bike store or industrial supply store.)

The tool you need for removal is here (http://www.biketoolsetc.com/index.cgi?id=27808617305&d=single&c=Tools&sc=Hub-and-Axle&tc=Bearing-Tools&item_id=UB-TA340)

That tool looks like what Specialized packed with their hubsets.

One thing to remember when you replace the bearings is to press the new bearings into the shell by the outer race only. If you use force on the inner race you will distroy them. One trick is to use to old bearing as a tool to press the new bearing in as it will exactly match the outer diameter.

Thanks for the tips and replies everyone. I guess the best plan may be to just remove the bearings when they go bad and take them into the LBS and have them match them to the correct bearing. The problem with that is that the last time I went into the LBS, I was interested in ordering some aero-style brake levers, and I had to argue with the "mechanic" and convince him there was such a thing as road brake levers that don't have shifters built into them. I have zero confidence that they can help me if I take a twenty-five year old cartridge bearing in to them. I would imagine most cartridge bearings sold these days are for suspension pivots in full-suspension mountain bikes, so I can imagine them matching these bearings up to something like that. That may be fine, I don't know. I was just hoping to figure out exactly what I'm looking for and just order it online, there seem to be plenty of sources. I just don't know enough about cartridge bearings yet to figure it out-

I'm wondering about something I'll probably have to deal with at some point in the future. I'm building up an early '80's touring bike, and it has Suntour hubs with cartridge bearings (40 spoke rear freewheel hub, 36 spoke front). For now, the hubs spin as smooth as silk, but I've never worked on cartridge bearing hubs before, and I'm wanting to know what I'm in for if and when the bearings go bad.
Those hubs were just great ...in their day...

I would not recommend using the rear one, because cassette Freehubs are superior in every respect to the old thread-on freewheel system.

These hubs are a great example of "if it ain't broke, don't 'fix' it." Other posters have addressed the issue of getting the cartridges out of the hub shell.

If you do need to replace the cartridges, they are a perfectly standard size. If you don't find 'em at your LBS, look in your Yellow Pages under "bearings" to find a local bearing shop, if you live in or near a medium sized city. These are common industrial products.

However, don't try to take the hubs apart unless/until they actually fail (which may be a LOOOOONG time--they're super reliable!)

If you have the model I'm thinking of, the axle locknuts are aluminum, with 4 notches for a special, no longer available wrench. In my experience, even _with_ the special wrench, it is just about impossible to get 'em apart without wrecking the aluminum nuts. SunTour evidently used some pretty powerful Loctite-like thread adhesive, and they're hellaciously tight.

Sheldon "Love/Hates Those Hubs" Brown

+---------------------------------------------------------+
| The Law, in its majestic equality, forbids the rich, |
| as well as the poor, to sleep under the bridges, |
| to beg in the streets, and to steal bread. |
| --Anatole France |
+---------------------------------------------------------+

Those hubs were just great ...in their day...

I would not recommend using the rear one, because cassette Freehubs are superior in every respect to the old thread-on freewheel system.

These hubs are a great example of "if it ain't broke, don't 'fix' it." Other posters have addressed the issue of getting the cartridges out of the hub shell.

If you do need to replace the cartridges, they are a perfectly standard size. If you don't find 'em at your LBS, look in your Yellow Pages under "bearings" to find a local bearing shop, if you live in or near a medium sized city. These are common industrial products.

However, don't try to take the hubs apart unless/until they actually fail (which may be a LOOOOONG time--they're super reliable!)

If you have the model I'm thinking of, the axle locknuts are aluminum, with 4 notches for a special, no longer available wrench. In my experience, even _with_ the special wrench, it is just about impossible to get 'em apart without wrecking the aluminum nuts. SunTour evidently used some pretty powerful Loctite-like thread adhesive, and they're hellaciously tight.

Sheldon "Love/Hates Those Hubs" Brown

+---------------------------------------------------------+
| The Law, in its majestic equality, forbids the rich, |
| as well as the poor, to sleep under the bridges, |
| to beg in the streets, and to steal bread. |
| --Anatole France |
+---------------------------------------------------------+


Thanks for the reply, Sheldon. I figured they were nice hubs, the bike's an '83 Centurion Pro Tour, and pretty much everything on it is nice stuff for touring (Sugino AT triple cranks, Suntour Cyclone Mk II RD, Mountech FD, etc.). Heck, the fact that it's got a 40-spoke rear wheel impresses me. And I appreciate the reassurance that the cartridge bearings are a standard type, that's very good to know. As for not disassembling the hubs, too late :D , I just had to tear into it and see what I was dealing with. I haven't removed the cartridges, though, and won't unless I have to, as you say. As for the disassembly, it did have a very strange, large, notched aluminum "nut" on it, and it did appear to have some loctite residue on the axle threads, but it actually came apart pretty easily without a special tool. Got lucky on that one, I guess. Thanks again for the reply!

In older cartridge bearings, the grease may have dried out. Is there a good way to force new grease in or otherwise provide fresh lubricant without removing the cartridges? I am thinking about the Suzue sealed hubs on my new/old tandem, fresh from sitting under cover in a garage for almost 20 years with all original components and only 200 miles on the clock.

In older cartridge bearings, the grease may have dried out. Is there a good way to force new grease in or otherwise provide fresh lubricant without removing the cartridges? I am thinking about the Suzue sealed hubs on my new/old tandem, fresh from sitting under cover in a garage for almost 20 years with all original components and only 200 miles on the clock.

I was wondering the same thing about possibly servicing the bearings with the cartridges still in the hubs; there's just something about using a bearing assembly that I'm pretty sure is quite old, and not servicing it, replacing it.......something. I've decided to take Sheldon's advice, though, and just ride mine as long as the bearings feel smooth, have no play, etc. But I do wonder about the possibility of popping the seal off and cleaning everything up and re-greasing, as I said in my original post. Cartridge bearings are cheap, but I wouldn't mind trying to service them if I was fairly well convinced I wouldn't ruin a perfectly good set of bearings by trying to remove the seal. FWIW, I have a Chris King headset on one of my bikes, and the instructions give a maintenance schedule instructing you to carefully remove the seal, clean everything up and re-grease. To tell you the truth, I'm way behind on that particular maintenance schedule (i.e., I've never serviced the bearings), but the bearings in that headset are the cartridge type of course, so apparently it can be done on at least some cartridge bearings............And btw, are you sure your Suzue hubs have cartridge bearings? I've had a bike from the '80's with Suzue hubs that had stickers on the hubs saying "sealed bearings," but they weren't the cartidge type, just a cup and cone assembly with a rubber seal-

Interesting point about "sealed bearings", but the front hub is definitely a cartridge and I assume the rear is too. I may just pop off the seal and try to squeeze some thin grease like Phil in there.