My guess was that the headset needed to be overhauled, or even replaced.
I'd seen some exploded view diagrams of headsets, and having overhauled wheel hubs, thought I might be able to give this a try. Since the Tricross uses a threadless headset, I was a little afraid of tackling this newer technology.
I searched the web and came across various tutorials and videos on how to do it. YouTube is indispensable here. Just take your time and watch lots of videos and take away the best parts from each. After seeing some how-to videos, I thought I might be able to give this a try.
All I needed were a hex key set, hammer, flat headed screwdriver, WD-40, bearing grease, a bowl to soak the parts in, and a rag for wiping and cleaning.
I took the headset apart and took some reference photos along the way so I could be sure I'd get it all back together right. The first thing I noticed that there was a lot of dirt or sand right under the top cover on the stem. I can't figure out how all that got there! Note that the bike is new to me, but it's a three year old bike, and likely, the headset was never serviced.
I used a flat screwdriver to knock out the races and bearing retainer. The bearings were really fouled. I soaked the races, ball bearings, retainer, etc. in WD-40 to get all the gunk off. I also used WD-40 and a rag to clean the cup and races. It seems the cups are integrated into the frame, which is bad news, since I think the top cup is damaged a bit. I think the BBs are a little mashed, too. I might get some new ones and do it all over again.
After getting everything clean, I put the BBs back into the retainer rings, packed it all with grease, and put all the parts back in the opposite order that I took them all out. I did have to tap the races with my screwdriver and hammer to get them click back into place inside the fork tube.
The end result is a remarkably smoother turning fork. I think I can still detect a little roughness, but it's smooth enough now that the fork will turn freely if I lean the bike from side to side.
Here are a few photos from the process. If you view the larger version, you can really see the caked on sand or dirt.
The bottom of the fork tube with the bike inverted. A little blurry, but you can see the ball bearings and some of the rings.
The purpose of this rambling fix-it is to encourage any other newbies like myself to try some basic repairs. With some research and patience, I've found that I can do some of these basic repairs on my own. It's fun, saves money, and gives me a little more confidence in tackling the next job.
To any experts reading this post, please let me know if I missed any points, or if I totally did it wrong and am now riding a rolling death trap.