Hello all,

My steering is really loose. I used to be able to ride with my hands, no problem, no if I let go of the handlebars my front wheel starts to wobble terribly. Also, If I lift the front of the bike up and let go of the handlebars, they will turn and bang into the frame.

I think my headset bearing is too loose, but I can't figure out how to adjust my headset. It's an older bike, 1986 Miyata two ten, and the headset only has one nut, then below that this knurled piece. I've looked up tons of how to videos on how to adjust headsets and it seems all of them have two different nuts that you can adjust, but not mine. How do adjust this type of headset? I've included a picture for reference.