blue steal

Hope someone can help me with my headset problem. I have a 1" headset, threaded. After every ride, 15 miles or so, the headset becomes loose. Not by much, but enough to make that "clunk" sound. It seems to be coming from the lower bearing area. I have read the Park tool website for headset adjustments, and have adjusted the headset many, many times, but it loosens up again. It seems that it is either to tight, or loose, with not much adjustment room in between, less than 1/16th of a turn. The LBS did my headset last year and it works well for a while. I have also noticed that each time I loosen the lock nut, the washer with the tab in it has moved out of alignment. What could be going on here? I measured to see if the lock nut was hitting the top of the threaded part of the fork when tighten, but there is still some space when tightened. I am out of ideas.

koine2002

I'd pull it apart and inspect the bearings, cones and cups. It could be that one or all are worn out. A switch to loose balls will often fix such a problem if one or all three are worn out. That many 5/32" loose balls are tedious, but it does make a difference.

seaneee

I recently had the same issue, took it to my LBS and all they had to do is add a spacer. It's been fine since.

Moose

What do you mean when you say the LBS "did" the headset? Did they replace it or overhaul it?

LCI_Brian

I'm having the same problem as the OP, with a 1" threaded Chris King headset, steel fork, steel frame. Only difference is that mine loosens after every 200 miles or so. Any ideas? Would upgrading to a threadless carbon fork help?

Mothra

Remove the washer with the key, that's the problem. When the keyed part gets turned when you turn the lock-nut on top, it binds the washer to the fork. You feel resistance in the lock-nut and think that everything's OK. However, that's just friction and binding in the washer, while the actual vertical-compression onto the adjustable cup is insufficient.

Also, when locking things down, it's IMPERATIVE that you use TWO wrenches; hold the adjustable-cup still while fully tightening the locknut. An even more secure method is to tighten the adjustable-cup a little too much, like an extra 10-20 degrees. Then as you tighten down the lock-nut, unscrew the adjustable-cup upwards into it.

And yes, upgrading to threadless headset & fork/stem will take care of that problem permanently...

Brian Ratliff

Upgrading to a threadless carbon fork will help all problems, up to and including world hunger.

Sometimes the problem is the top nut is bottoming out against the top of the steering tube before it makes good contact with the bottom nut. This is solved by using one of those keyed washers between the two nuts. Then use two wrenches to tighten the two nuts against each other so they won't come loose. If the key on the washer is binding (though this usually isn't a problem, since it is steel on steel), you can use an unkeyed spacer made for the threadless stem as well (make sure it is aluminum or steel though, don't use carbon fiber or plastic).

HillRider

This is a problem that often comes up when discussing threadless steerers and headsets but is rarely mentioned with threaded set-ups. However, you are correct that a too-long steerer will bottom out against the headset's top nut and prevent getting enough tension to hold the headset adjustment. There should be 2 or 3 mm of clearance between the top of the steerer tube and the upper face of the top nut when the headset is adjusted and tightened down. A washer or other thin spacer can be used to assure this gap is correct.

I'd further recommend the top nut be thigtened VERY FIRMLY while holding the upper race in place with a wrench.

powers2b

File the "tab" out of the washer or get another tabless washer.
+ what everyone else said.

blue steal

Moose, I had the LBS replace the headset maybe a year ago. Seanee, I will try to add an additional spacer to make sure there is adequate clearance between the threaded tube and the top nut. Powers2b, I may also just file off the exsisting tab. If this does not work, then I'll switch to loose balls. Right now it is a caged typed. How do I know what size on the loose bearings? Is 5/32th a standard for 1"? I have always used two wrenches, first tightening down the adjustable nut until there is no play, then tightening down the lock nut while not letting the adustable nut move. That works for about 15 miles, then loose again. Thanks all, I'll have a go on it this weekend.

simplify

This is an extremely good idea in any case. One of the best things you can do for your headset. Most 1" headsets take 5/32 ball bearings, however I have a mid-80's vintage Campy 1" headset that takes 3/16 bearings. Only way to know for sure is to take out the old ones and compare them to the new ones you're buying. The difference is very visible when they're side by side.

LCI_Brian

In my case, my headset has the Chris King "Grip Nut".

blue steal

My steed is a 93 Univega and has used caged bearings for 14 years. I've gone thru maybe 3 or 4 headsets in that time. I am curious as to what would be the advantages of loose balls over caged? Smoother turning? Easier to adjust?

Moose

A new, properly installed headset should be easily adjusted and hold that adjustment. I would make sure the mechanic did not take a short cut and re-use the old crown race.

blue steal

I have noticed that the crown race is somewhat loose on the fork, that is, I'm able to turn it when I have the fork removed but there is no play. I am not sure if the crown race is supposed to be "pressed" onto the fork stem or what? Any thoughts on this? I was going to take the fork to the LBS to have it checked out, pick up an additional spacer, and some bearings. The race itself looks clean with no pitting.

simplify

You can fit more bearings into the headset if they're not caged. More bearings means more surfaces to receive the impact, meaning less force on each one. It takes longer to develop pits in the races (called "brinnelling"). Also, the position of the bearings is not fixed, as it is in a cage. Therefore, the bearings move around more and don't always impact the exact same spot. Again this helps prevent brinnelling.

simplify

The crown race should be pressed onto the fork crown, and shouldn't move. Since you have no play in it, it may not be critical now, but over time, it may develop play. If you can take it back to the shop that installed it for you (assuming this is one of the several replacement headsets you've gotten in the last 14 years), they should press it on properly. It sounds like they did not install it correctly to begin with.

HillRider

Or they installed a JIS crown race on an ISO fork but that should give a noticable amount of play when the headset is disassembled.

OLDYELLR

The crown race should be a press fit. If it's the right one and just not tight enough, remove it, clean it and the steerer and reinstall it using Loctite. The advantage of loose balls icer caged balls in this application is that there are more balls to take the load, so less chance of denting the races. You should use one less than the maximum number that appears to fit. Caged bearings are for higher rotational speeds where you don't want the balls rubbing against each other. They are also quicker to install, which is probably why they're used by manufacturers.

Mothra

Slightly smoother and more durable due to the larger number of contact points to spread out the load. However, due to the tiny, tiny contact area of ball-bearings, the pressure where they roll is immense. Using roller-bearings spreads out this force by a significant amount and those pretty much last forever. I've got a Stronglight headset on my bike for over 16 years now and have only regreased it about every 5-years.

As for the loose fork-crown, you should definitely measure the ID of the crown-race and OD of the fork-crown. You want a tight interference press-fit of about 0.05mm. There's two sizes of crown-races, 26.4mm and 27.0mm. Make sure you don't have the larger crown-race on the smaller fork-crown...

blue steal

Well I took it all apart and the top lock nut was not hitting the top of the threaded part of the fork, had about 3-4 threads left. The crown race was loose and upon closer inspection it did some some play. I took the fork back to my LBS. He replaced the crown race with a new one. I have reassembled and adjusted everything back up and tried a small ride around the block. Seems to be okay for now. I will give it a good ride Tuesday. I did not switch out to individual balls because I want to see if it was in fact the crown race causing the problem. I think I will make the switch though. I counted 16 bearings in the cage with both top and bottom appearing to be the same size.
Some people are saying to fill the area, then remove one ball and others say remove two. Would like to know where to buy the bearings as my LBS guy wasn't to keen on it. I know there are different grades of bearings and sounds like I may need about 50.

mechBgon

That shouldn't be happening. Inspect the key (the "tab") and the fork. The fork shouldn't have had its threads peeled off by the key. Neither should the key have had threads cut into it by the fork. The purpose of this guy is to keep the headset adjusted the way you left it.

It's not hard to accidentally "spin" the keyed washer when tightening the top nut, particularly if you're not holding the adjustable cup stationary with a second wrench. You can help by greasing the bottom face of the top nut, so it's greased where it lands on the keyed washer, and thus it's not as likely to spin the keyed washer and strip the key (or the fork's threads).

Also, look at the keyed washer and it may have one face with rounded edges and the other face with sharp edges, like a stamped-metal part often does. Put the sharp side down, and the rounded side up, so the top nut is turning against the side that's got rounded edges.

If the keyed washer is damaged, get a new one, preferably a steel one.

blue steal

mechBgon I think the tab has worn down enough to where it is not catching in the slot on the fork. I may either just file the tab off competely or get another washer with a tab. You are right, I noticed the washer has a sharp serrated side which I place down and the smooth side up. I like the idea of a bit of grease between the smooth side of washer and bottom of lock nut.

HillRider

Now I'd put money on the fact that somewhere, someone installed a JIS crown race on an ISO fork.
You want "Grade 25" bearing balls (lower grade numbers are higher quality. Grade 25 is far superior to Grades 200 or 300.). Any auto supply or bearing supply house can sell them to you in packages of 100 for a few dollars. Bike Tools Etc. also has them at very reasonable cost. Measure one of the original balls and get a bag of the same size. BTW, replace all of the balls when you redo the headset, don't just add new ones to the existing set.

blue steal

HillRider thanks for the information on the bearings, I'll look for Grade 25. How does one measure those little boogers? I don't know the difference between a JIS crown race or an ISO, but I still have the old race and it does look different in it's shape.