May 9, 2001 2:14 AM
|I've got a dilemma - please read the following novel, as I'll try to get all pertinent info included in the first try. I have an 8sp Campy Chorus rear hub I recently rethreaded for a new wheel. Its been a good, solid performer for a couple years now (~1700 miles). The other night, I noticed some brake rub while riding. I checked the wheel, and there was some play (~3mm side-to-side), just like a hub/wheel feels like when the cones are set too loose. I assumed my cones needed adjustment, so I readjusted them that same night. The play wouldn't disappear. I tore apart the hub and noticed that the bearings needed new grease...so an overhaul was performed. I cleaned the bearings/hub surfaces, added copious amounts of Phil Wood Waterproof grease, and reset the cones. The problem disappeared.
I rode my bike for a couple of days, only to see that the problem reappeared. The cones were set as tight as a smooth running hub could get before it had noticeable resistance. I did observe that the hub's grease ports oozed alot of the grease out, as I probably overstuffed it.
The questions: 1) Should grease be a factor in the play I'm observing? 2) If not, what would cause the play? I should add that the correct size bearings were replaced on their correct sides during the overhaul. 3) Would initial overtightening of the cones compensate for excess grease in the hub, and then stabilize?
Any help would be greatly appreciated...I really don't want to have to rebuild the wheel with a new hub!!! Thanks for your help!
|re: Hub Play||grz mnky|
May 9, 2001 1:05 PM
|The grease should be irrelevant when setting up the cones. It just adds some viscosity, but is squeezed out of the way. Over packing with grease pushes the excess through the seals, makes a mess and attracts more dirt. You could actually blow the seal out and thus allow grit to enter. |
It sounds like your cones/races/bearings are worn from not keeping up with the service. The typical symptom is that you can't seem to ever get the setting just right. This doesn't happen over night.
|Yes but||Kerry Irons|
May 9, 2001 7:01 PM
|A Campy hub certainly shouldn't need an overhaul after 1700 miles unless you got caught in a lot of rain. A visual inspection of the cups and cones should immediately tell if there is any pitting - pitted cups or cones would show as indentations or width variations in the wear line on the cone. The bearings should be shiny when cleaned of grease - a dull finish suggests wear. Axles should be checked to be sure they're straight - roll the axle on a flat surface. And double check that you have the smaller bearings on the cassette side of the hub and that you have only 7/32" on the right and 1/4" on the left. The fact that the hub can be adjusted properly and then "gets loose" after a few miles suggests something is amiss.|
May 9, 2001 9:10 PM
|Thanks for the help guys...I ended up figuring it out, so I'll post the solution for others' reference if needed.
I ripped the hub apart again. Bearings were installed correct, no pitting in bearings or cones, axle's straight. I reassembled the hub and in doing so, realized that I had not allowed the rubber seal in front of the non-drive side bearings to seat correctly. Playing with it abit, I found that a person could accidentally press the seal too far inside the dust cap, and still get a seemingly OK seal against the cone (which was the case I had experienced). The play I was noticing was the rubber slipping in and out of the space between the bearings and the hub race. I installed the seal correctly and voile'...everything's great...Campy smooth as expected.
Moral of story: Don't make a habit of doing repairs in dim light late at night...get some sleep and look at it in the daytime. I frequently do "bike" things at night when I'm not as likely to be disturbed...but in this case, it ended up creating the problem.
Thanks again for your responses...