Hub dissection...help!?!

[killacks]

I recently purchased a used wheelset and it appears to my novice sensibilities that I should put in a little work before riding them. They spin true, but the hubs sound a little gritty. So, have I stumbled on an opportunity to repack the hubs??

They are Mavic OPs to Suntour Superbe track hubs. Sheldon Brown had some good advice on how to do this, but are there any other pitfalls to avoid, especially for a tinkering newbie like myself?

Thx

[Gummee]

Mavics typically have sealed bearings. All mine have had em anyway.

G'luck!

M

[vsefiream]

Just repacking might not cut it. I would completely disassemble the Superbe hubs and clean everything thoroughly. Then inspect the cones where the bearings ride on the axle. The cones should be smooth in the con-caved area where the bearings contact. If the cones are black, I would not be surprised to see a silver mark where the bearings ride, that's fine, but it must be smooth. I would bet that you will find wear in that area (pitting) causing your grinding feeling/noise. If not then bonus!! Usually replacing the bearings and cones will fix the problems if the cups in the hub body are still OK.
When you reassemble, use a good quality grease to repack the bearings and be sure to adjust the cones properly. This requires the use of a cone wrench and a standard open end wrench. The axle should spin smoothly with no axle play and only the slightest hint of pre-load on the bearings. When you are done they will spin smoothly and quietly.
Good luck

[forrestw]

Track hubs generally don't have seals (not intended for outdoor riding) so plan on frequent maintenance and maybe don't ride these wheels in rain if the hubs have no seals.

If the bearings races are pitted a thorough cleaning and replacement of the bearings will breath new life into the hub. New bearing balls should *all* be new, don't mix any of the old ones in no matter how good they look.

Even if you can get similar quality cones to what was in there before, you're stuck with the cup (hub) races. The good news is that while they may not be perfect, you can continue to ride on damaged cup/cone hubs for many moons, just plan on more frequent overhauls than would be normal.

I still occasionally ride on a rear wheel with an old but working Maillard hub / freewheel. Back when I didn't take such great care of my rides it suffered a couple of split bearings and significant scoring. + the axle bent multiple times and eventually broke to be replaced with something a little stiffer but still prone to being too weak. Even given the past abuse this hub has more miles on it post-abuse than prior and still spins freer than many modern sealed rear hubs.

[killacks]

I started to take apart the hub and low and behold the bearing was not of the loose ball variety, nor the sealed cartridge style. Rather, it looks like a mix of both. After some googling, i cam across the following link, which addresses the issue specifically, but the discussion ends before adequate follow up is given.

http://www.bikeforums.net/archive/index.php/t-367171.html

What I am looking at now is a hub shell with only the outer bearing race pressed in. How can I remove it? (I know suggestions are offered in the link but any new ones??)

Secondly, if I were to attempt to replace the "hybrid" bearing setup with a standard cartridge bearing, do I need to replace the cone nut that acts as the inner bearing race?

Please excuse me if any of these questions sound stupid. Im pretty new to all this. Thanks in advance!

[forrestw]

That sounds to me like an angular contact bearing, Surly uses them in their track hubs (spec 7901 in that case) I happen to have bought a set of those in poor condition a couple years back (adjusted the bearings lastnight).

What I did to extract the race was chopped the end off a spare 5mm allen wrench, forming a 'J' shape w/ a short/thin tail which I re-hardened and then used to carefully tap out the race -- 'J' tool thru hub engaging the inner edge of the race, working around the race moving each side maybe 1/32" at a time. Depending on the hub, you might be able to use / make a headset extractor - like tool but that would not have worked in the Surly.

I like this bearing type but they can be hard to work with.

[Gummee]

Reading comprehension. I haz it.

Duh!

Sorry guys!

M