Originally Posted by
masi61
What was wrong with the original CK no-thread headset? Just curious because I thought these lasted pretty much indefinitely.
Almost indefinitely but even the King headsets can be vulnerable to decades of neglect.
My 1993 Trek 5900 OCLV came with lots of nifty titanium components, including a titanium Chris King 1" threadless headset. I bought the bike used from a friend in 2019, and it had been used as a TT/tri-bike by the previous owner.
After several months of happy riding, in December 2019 I noticed a bit of grinding and sluggishness in the headset. When I tried to drop the fork for inspection it wouldn't slide out easily so I tapped it very carefully with a rubber mallet. The CK headset came apart and the fork steerer tube was coated in a tan/brown crust. Even the cartridge bearings came apart and the headset was filled with the same crusty brown stuff.
At first I thought it was rust or lime scale, so I used CLR to clean it up. Zero effect on the crusty gunk.
Then the penny dropped and I realized what it probably was.
My best guess was it was an accumulation of years of sweat and electrolyte/drink mix drooled down the headset and fork from the rider leaning across the aero bars. Eventually it built up and dried out enough to cause problems.
I've seen identical stuff in the rear hub of another tri-bike, also sealed cartridge bearings. Again, it appeared to be dried crusty residue from sweat, electrolyte/drink mix or... worse. Like, urine. Not unheard of with diehard tri-folk. Or marathoners -- recently a 30something woman sort of shame-bragged about pooping herself during a full marathon but refusing to make a pit stop. She was prepared with absorbent undies and determined to finish with her best time, exhaust problems be damned. Endurance athletes are a strange breed.
Anyway, I emailed the folks at Chris King. They offered to service that older titanium headset for $25. I keep forgetting to send it to them. The 2020 pandemic rolled around and other stuff took priority. Meanwhile I've installed a basic Origin8 1" threadless headset, but eventually I'll re-install the original CK unit. If I'm correctly recalling an interview with Chris King himself several years ago he admitted the titanium headsets weren't any better but, hey, it was the early 1990s, the first monocoque carbon fiber frames were catching on with some pros, and suddenly everybody was a weight weenie, so titanium seemed spare-no-expense sexy. And it is. That early Trek 5900 has a titanium American Classic seat post, single-bolt Ibis stem (much prettier and more svelte than the 4-bolt FSA stem it wore for awhile in 2019), White Industries bottom bracket and one or two other titanium bits. Properly set up that bike could still be a featherweight by contemporary standards, although it really needs a lighter fork. The original carbon fiber fork was made like a steel fork -- solid wrapped, not hollow -- and the steerer tube is steel, quite heavy.