Alrocket

I've recently replaced my threadless MTB fork. I got a new starnut but left all the other pieces in place. After installation and some mileage it felt like the headset was very slightly loose, that slight knocking you get. Yet steering seemed to be more difficult than prior to installation of the new fork.

I've loosened up and reset the fork and stem several times, and although turning is "easy", I can feel a drag as I move the bars all the way from one side to the other. I'm wondering if this is because my headset is worn out, or if I'm missing a piece. There is nothing removable at the bottom of the head tube where the bottom of the fork steerer tube meets the frame. Should there be another circular pack of bearings there too? Do I need a new headset? Any other suggestions for figuring out what the problem is here?

moxfyre

Are you sure there are NO bearings at the bottom of the head tube, neither loose bearings nor a sealed cartridge? I have great difficulty believing that the bike would be even slightly rideable with these missing

If there is in fact a sealed cartridge bearing, it is removable, but press-fit into the headset, so you need a special tool or something like a PVC pipe to remove it. The good news is that if you replace the bearings (loose balls or cartridge bearings), you'll likely rejuvenate the headset. Assuming it is a cartridge bearing headset, it'll probably cost $5-10 for new bearing cartridges online.

Alrocket

No, I'm ashamed to say I'm not 100% certain there's not a "pressed to fit" device of some sort. I didn't feel anything movable. Is the pressed frame race on the bottom distinguishable easily? Maybe I'm confusing it as part of the frame.

Headset is a Cane Creek Aheadset stock on an '04 Trek 4300. It's a sealed headset - can I open it up to regrease and replace bearings?

I think it looks a bit like the "Integrated- Angular Contact System (without cups)" as here: https://www.parktool.com/repair/readhowto.asp?id=68

moxfyre

The pressed race may be a bit hard to distinguish. It should look like a round cartridge with a thin seam around the outside. The cartridge in that Park Tool page is the black and red round thing held by the gloved hand.

You'll know it's the right part if you can spin half of it independently of the other You can't open these up, but the whole cartridge can be replaced for a few $ generally. The nice thing about cartridge bearings is that they're less messy and require less adjustment than C&C bearings. Also the cartridges typically are well-sealed and last a long time... though yours has only lasted 2 years it seems.

dlapasky

It sounds to me like you didn't remove the bearing race off your old fork. It's hard to tell for your picture, but it looks like the headset bearings are sitting directly on top of your fork crown. If you look on your old fork, you will see a piece that is designed to go against the bearings in the headset. If you turn your old fork upside down, you can take a flathead screwdriver and hammer and tap the race off of your old fork. It is a press fit piece, so it may take a little work to get it off. Once you get it off, you'll want to take your new fork and the race from your old fork to a shop to have them install it. If you don't have the proper tool, you can damage the bearing surface on the race and your headset will not work smoothly. Good Luck!!

moxfyre

+1 ... that sounds like it could definitely be a possibility, a missing fork crown race

Also: you *can* reinstall the race without the special tool. One way to do it that works well for a lot of people is to find a piece of PVC pipe of the appropriate diameter. You slip it over the fork crown and use it to push the race down into place. It's soft enough to prevent damage to the race.