Ultegra Hub Question (Service)

[Ken C]

I had an Ultegra 6600 front hub repacked with new grease by a local bike shop last November. They were two years old at the time and that was their first service (I know I should have it done yearly) Anyway the grease began working its way out around the edges of the dust covers. At first I thought it was just a little extra, but now it seems liks most of it has come out. When I spin the wheel it sounds like the bearings are grinding. My question is what would cause this to happen? Is the the dust covers or is there a seal that holds in the grease?

I bought Zinn and the Art of Road Bike Maintenance and I was going to repack them myself, but I thought maybe I should bring them by the shop that did the repack. I am in no way blaming them for what happend, the rear works flawlessly and they have a solid reputation for service.

Also for discussion sake, lets say I did pit out the hub from a lack of grease, is it possible to replace the cups and cones? Thanks for your help.

[staggerwing]

The bearings on all Shimano hubs that I've seen are more shielded than sealed. You mention having them repacked in November. By chance, did you use them in the winter slop. I had a set of Campy Athena hubs on my commuter rig, and they didn't take kindly to running in midwestern winter salt water. About 6 weeks was all I could expect between repacks in the winter. If you never ride in the rain or slop, I can see going much longer.

FWIW, this is not a difficult job at all. A jar (leftover peanut butter jar is fine) with a couple of ounces of mineral spirits, some tweezers, cone wrenches, grease, and a roll of paper towels are all you need. Work over a clean lunch tray, to catch the loose balls, when they fall out. Tweezers will grab the ones that don't immediately drop out, and are helpful for putting the cleaned balls back in the grease lubed cups. The cones can be replaced, if damaged. However, the cups are pressed into the hubs and I don't know of any way to replace them.

Park Tool will likely have a completed, detailed guide on their site.

[AgilisMerlin]

repacking a hub makes me warm and fuzzy.





repack the hubs, read how. It is all good. :D

[barry1021]

it depends what you mean by grinding. It it feel like it "catches" a bit when you spin it, probably just a re pack, but if its really grinding, it could be damaged. Since you haven't done one before, I would take it to the shop. JMO

b21

[Peter P.]

Rotate the axle with your fingers. If you feel roughness, the races are contaminated with grit or they are pitted. If grit, then clean and repack. If pitted, there's no sense in repacking them. Either ride them into the ground as is, or replace them.

If you rotate the axle and they feel smooth, then there's no problem. Excess grease will always ooze out of the hub. You'll always be left with the right amount of grease and a watertight seal.

[jthurow]

If you do repack it yourself, splurge and get new ball bearings. They'll cost you all of about $5.

jimi

[Ken C]

I did it the myself. The races and the cones looked fine and there was plenty of grease still in the hubs. It just seems like some grit made its way in. The two shops near my house did not have the correct size bearings (they both are lame) so I repacked with new grease and the old bearings. The hub now spins flawlessley and smoothly. Thanks for the encouragement to do it myself, it was not hard at all. I will however go tthe shop I like that is more out of the way and go get new bearings to put in later. Thanks again.

Ken

[11.4]

Actually sounds more like the cones are a bit tight. This can happen easily if the locknuts weren't quite tight enough, and a surfeit of grease can conceal the problem at first. Those hubs put up with a lot of bad weather without problems, so when relatively young hubs get gritty I suspect adjustment as the cause rather than dirt contamination.

[Ken C]

It did take me a few takes to get the cones right, loose enough so they spun freely, but ever so tightly enough that there was no play. On one of the first passes I did have them way overtightened and they did have a similar feel to before I repacked them. Anyway, it was a great learning experience and now I have them cleaned out and adjusted so they are back in business.