Bicycle Mechanics - Loctite on Threaded Headset Lockring: Asking for Trouble?

The headset on my fixed gear bike is always coming loose (I get a little "knocking" when applying the front brake and pushing the bike forward). I've never really had this problem on threaded headsets before. I greased it, but it seems like I have to tighten the lockring/adjusting cup every other ride. Should I try a little blue loctite on the threads of the lockring? I'm hesitant to get this stuff anywhere near bearings, so I'd like to avoid having to use it. Am I missing something?

Make sure the mating surfaces on the top of the race, the lockwasher, and the locknut are clean with no grease. Adjust properly. Tighten firmly with wrenches on both sets of wrench flats. It should not come loose. If you start off with the headset adjusted too loosely it can tend to loosen up more while you ride. If you can't adjust it to eliminate play, may be time for new bearings or headset.

A properly adjusted threaded headset shouldn't require constant re-adjustment and tightening.

sounds like you need an additional spacer. after you adjust the headset, remove the stem: there should be a mm or two between the top of the steerer and the top of the locknut. either that or your fork crown race is loose.

This is how I'm adjusting it:

1. Loosen locknut.
2. Tighten threaded top race by hand as far as possible. Back off a quarter of a turn.
3. Tighten locknut all the way down.
4. Press brake, push bike forward. Feel a "knock". Back off locknut, tighten race. Tighten locknut.
5. Making small adjustments, continue until there is no play left.
6. Torque down locknut.

I only have the one headset wrench, but I don't think having two would make a difference (when I'm turning either the locknut or race the other one is not moving). I think maybe the headset is done, it was a cheap no-name that came on the fixed gear bike.

Thanks for all the suggestions, I'll see if it gets better or I'll just buy a new headset. Is there anything obvious I'm missing?

Second wrench does help - greatly - but if your race really is not turning when you tighten down the locknut than I agree that


sounds like you need an additional spacer. after you adjust the headset, remove the stem: there should be a mm or two between the top of the steerer and the top of the locknut.

+1 to second wrench. In fact, I think it's crucial to setting things up so that you don't have loosening. Here's my progression:

1. Loosen top nut.
2. Tighten top race until I have the right amount of spin in the headset without loose fork.
3. Holding the top race with one wrench, crank the topnut down with another. In this step, like on hub cones, you're tightening the two together so that they don't loosen.

Without the 2nd wrench, all you are doing when you tighten the top nut is compressing the whole headset and thereby losing your perfect adjustment and setting yourself up for a loose topnut in the near future.

I have this problem on my fixie, but it's because I bought the cheapo Nashbar headset with aluminum cups. Won't do that again.

This is how I'm adjusting it:

1. Loosen locknut.
2. Tighten threaded top race by hand as far as possible. Back off a quarter of a turn.
3. Tighten locknut all the way down.
4. Press brake, push bike forward. Feel a "knock". Back off locknut, tighten race. Tighten locknut.
5. Making small adjustments, continue until there is no play left.
6. Torque down locknut.

I only have the one headset wrench, but I don't think having two would make a difference (when I'm turning either the locknut or race the other one is not moving). I think maybe the headset is done, it was a cheap no-name that came on the fixed gear bike.

Thanks for all the suggestions, I'll see if it gets better or I'll just buy a new headset. Is there anything obvious I'm missing?

You have to have two wrenches to do this properly, you simply won't get enough torque to secure the assembly otherwise. If you have a headset wrench already, just use the headset wrench on the cup and a BFAW (big f@cking adjustable wrench) for the locknut. Be sure the threads are clean and lubed and that the mating surface between the locknut and cup are lubricated.

I'd concure with the two wrench crowd. Also something that helps is a keyed spacer between the threaded top race and the locknut. I had the perpetually loosening headset problem once, and it turned out that the locknut was bottoming out and hitting the top of the steering tube, preventing it from fully tightening down to the threaded race. You should be able to get this from the bike shop, though anymore, you might have to make due with a thin 1" threadless headset spacer in place of the keyed spacer. With the keyed spacer, you probably can get by without a second wrench. Without the keyed part, you need a second wrench to keep the threaded race from turning while you apply torque to the locknut.

Here's what I normally do:

1) back off the locknut
2) tighten the threaded race all the way down (no backing off a quarter turn)
3) thread the locknut to the level of the threaded race
4) using two wrenches, one on the race and one on the locknut, I tighten the locknut while keeping the race from turning
5) test rotation to see if it binds. If so, using two wrenches again, keep the locknut from rotating while loosening the threaded race. If done right and with round and relatively unworn bearings, the race should loosen just enough to keep the bearing from binding while allowing no play in the headset. That rotation will be waaay less than a full quarter turn.

FWIW, I'm with San Rensho on the BFAW. I have one headset wrench and a big crescent wrench which pulls double duty with other tasks. You really do need the headset wrench on the race though, as the flats are pretty narrow. And again, the keyed spacer helps with the tightening process.

Oh yea, don't use locktite. You shouldn't need it and you'll just gum up any attempts at adjusting the headset in the future. Plus, locktite dripping down in amongst the ball bearings is probably bad.

The second wrench really helps tighten down that locknut.

New headset wrench (or bigger adjustable wrench) on the way. Thanks for the advice.

A properly adjusted threaded headset shouldn't require constant re-adjustment and tightening.

or Locktite

The headset on my fixed gear bike is always coming loose (I get a little "knocking" when applying the front brake and pushing the bike forward). I've never really had this problem on threaded headsets before. I greased it, but it seems like I have to tighten the lockring/adjusting cup every other ride. Should I try a little blue loctite on the threads of the lockring? I'm hesitant to get this stuff anywhere near bearings, so I'd like to avoid having to use it. Am I missing something?
do the oppisite, and de grease, and tighten as best you can, should never grease the thread., if it persists you should have it fited at bike shop, i'tll cost the same as a new bike.

if it persists you should have it fited at bike shop, i'tll cost the same as a new bike.
:roflmao:

Using two wrenches is necessary to get the torque on the locknut needed to keep the top race in place. I've had a threaded headset loosen on me of I don't get it torqued with two wrenches. If you only have a few mm's of threads above the race, then you should be alright there, else get a 1mm spacer and try adding that. Should allow you to get the race and locknut set snugly.

Going to have to disagree with not greasing the threads. You probably don't want to grease the mating surfaces of the locknut/spacers/race so that there is a good set between them, but having a little grease on the threads will help prevent anything from seizing up.

Using two wrenches is necessary to get the torque on the locknut needed to keep the top race in place. I've had a threaded headset loosen on me of I don't get it torqued with two wrenches. If you only have a few mm's of threads above the race, then you should be alright there, else get a 1mm spacer and try adding that. Should allow you to get the race and locknut set snugly.

Going to have to disagree with not greasing the threads. You probably don't want to grease the mating surfaces of the locknut/spacers/race so that there is a good set between them, but having a little grease on the threads will help prevent anything from seizing up.

Sorry to nitpick about the mating surface issue, but the reason the headset stays tight is because of the clamping force between the cup and lockring. If you lubricate the mating surface you will get more clamping force for a given amount of torque and therefore more holding power.

If you use enough loctite that it is dripping off, you are using to much(Not that you need it for this)