Hey, y'all. Thought I'd try my hand at a mechanics tutorial since we haven't had much content to post lately (but hey, if you only posted original content how often would you post?). Heres the first in what may become a series -- how to overhaul a threaded, unsealed headset.
Note: I posted this on a popular online bike forum and asked for some feedback and have a couple things to add.
1. The orientation of the ball bearing cage isn't always necessarily ball-side-down, the ball side should face the bearing race, which is almost always down for the bottom race, but can be either way on the top race.
2. When tightening/adjusting the top nuts of a headset, use two wrenches, one to hold the bottom nut in the correct position, and the other to tighten the top nut.
3. Some people suggested that the amount of cleaning of the ball-bearings was overkill. Indeed, if you regularly maintain your headset, all thats really necessary is a wipe down with a clean rag and some fresh grease. This headset (like a lot of "track" headsets, which have no grime seal on the bottom) was thrashed, so it needed a lot of cleaning.
4. I wrote "biodegradeable, please" about what degreaser to use. I was informed that "bio" degreaser is no longer bio-degradeable after it has grease and grime entrained in it. So I'll take the opportunity to say this, use as little degreaser as possible and dispose of it responsibly. Degreaser should be landfilled or taken to a solvent disposal site, not dumped. Regardless of what jerks on the internet say, I still think citrus degreaser is better for the environment than a solvent like tetrachloroethene.
5. The frame (not mine) in the photos is busted, you can see damage in the paint/tubing where the headtube meets the top tube and down tube. If your bike is damaged in this area, its not too safe to be riding hard, and you should keep a close eye on the damage to make sure it doesn't get worse.\
6. Finally, this Park Tool page has everything you could possibly want to know about threaded headsets.