Headset keeps coming loose!

Discussion in 'Bicycle Repair' started by kjparker, Jun 12, 2008.

  1. kjparker

    kjparker Member


    I have a problem where my headset keeps coming loose!

    It is a threaded headset, in three parts:
    • A knurled circular nut
    • a slotted curcular nut
    • a hex shaped nut / seal

    I have (many times) tightened it all down, yet it still comes loose!

    the process I have followed is as follows:
    • tighted down knurled nut untill the tension on the headset is correct
    • tighten down slotted nut to lock it
    • tighten down the hex nut on top of it all to further lock and seal

    Yet it still comes loose!


  2. turkeyssr

    turkeyssr Guest

    Don't take the following as criticism, but you have a cheap headset. For about $20, you could have a good quality headset that won't give you fits like this one. I, as you, have not had good luck with this type of headset. The better versions have a 'nutted' version of the 'knurled' nut that you have. You then can get a wrench on it to hold it as you tighten the nut on top.

    If you decide to get a new headset, make certain you get the correct size. It sounds like you have a 1", but 1" isn't always
    1". There's BMX 1" that takes a .833"/21.15mm stem and there's "modern" 1" that takes 7/8"/22.2mm stem. There are other dimensions to consider depending on what parts you're going to replace. Let me know if I can help.

    Last edited by a moderator: Jun 12, 2008
  3. kjparker

    kjparker Member

    no offence taken. I'm looking for answers as to why it's comes loose. If that answer is beacuse it's ****, then so be it!

    I was also wanting to make sure I wasnt doing something wrong with the procedure I was following.
  4. turkeyssr

    turkeyssr Guest

    I would also check your slotted washer. Is it worn at all? They're not expensive if you want to try a new one from your LBS.
    Last edited by a moderator: Jun 12, 2008
  5. kjparker

    kjparker Member

    doesnt look to be, Might be changing the headset altogether shortly, want to change to a threadless heatset....
  6. lennyharp

    lennyharp Member

    If the above still fails the frame may not have been properly finished. The head tube needs to me milled after manufacture before the headset is installed. You can have a shop do that for you with a milling tool. A quality headset is important too. A junker will often keep this problem for life.
  7. kjparker

    kjparker Member

    It isnt worth spending a huge amount on this frame, it's a malvern star, and quite old.

    I have some suspension forks coming, which will necessitate the need for a new headset, so hopefully this will address the issue!
  8. bikejohn

    bikejohn New Member

    Actually, the cheapness of a headset doesn't determine it's ability to stay tight. If it were every bike sold at the 'mart stores wouldn't make it two blocks.

    To properly tighten a headset you need to tighten the bottom nut (technically called a threaded top race) upwards against the lock nut--or lock ring. Find your bearing adjustment, thread on your lock ring, then once they touch each other--with a wrench on the bottom nut, and proper spanner on the ring (could be a wrench or something to fit the slots) tighten them together--clockwise on the top, counterclockwise on the bottom. Recheck your adjustment, then loosen and readjust--and tighten against each other again. Repeat as necessary. And tight means good and snug against each other. Then screw on the top nut and just snug with a wrench.

    Reading your first post it looks to me that you are adjusting the first nut, then tightening the lock ring down to the first nut, then tightening the top nut. What is probably happening is that since the bottom nut isn't actually tight (it's only slightly touching the balls--not much contact surface there) it can move--and when it does the lock ring is now loose. You tightened the lock ring against the bottom nut and the bottom nut moved. When you added the top nut and tightened it, and the bottom nut and lock ring loosened--it loosened as well.

    You have to tighten the bottom nut and lock ring against each other. Some headsets use an indexed or toothed washer between the nuts, but you still have to tighten the two nuts against each other.

    Hopes this helps.
  9. Let's go back to that slotted washer. It's in that slot,I assume of course. Does it have any play when it just sits in it's groove by itself? Does it look like it can go past the groove and ride on the threads?
    Try getting two slotted washers on there. That top nut should not in any way get loose if it rides on a washer that can't turn.
    Another thing to check is your bearing nut,meaning the top nut that sits on the bearings. It must turn freely with handlebar movement. If you turn your handlebar and that nut does not turn then it's stuck on your bearing cage and it's actually riding on your threads.
    If your bearings are worn to the point that your bearing nut is so screwed down that it's rubbing against the bearing cage of the bike frame that this will cause your bearing nut to move loosening your assembly.
    But that slotted washer is key here. Even if that bottom nut moves that slotted washer should keep everything above it from getting loose.
    Last edited by a moderator: Jun 14, 2008
  10. bikejohn

    bikejohn New Member

    Large, I'm assuming that there isn't a slotted washer, but a slotted nut (see o.p.). The slot on this type is a slot similar to a wide screwdriver slot in the top of the lock ring (or nut)--which is usually countersunk into the bottom nut. Since the slot is in the top, it's impossible to hold this when tightening the top nut--so you have to tighten the lock ring against the race. The top nut on this type of headset then somewhat jams the lock ring/bottom nut by holding the bottom nut and tightening the top nut against the pair.

    If you're using a tabbed washer type of headset where the tab goes into the slot cut into the headtube,--or the European type with holes or teeth-- then you absolutely have to back the bottom nut into the top nut. The washer won't hold --it's just floating between the two nuts. Usually backing the bottom nut involves less than a 32nd of a turn or so--not much.

    The bottom race should never move on the headtube once the nuts are installed. If you rely on just the two top pieces to keep the bottom nut from backing off, you run the risk of it tightening itself--and this would be more disastrous. If a headset loosens when riding, you can probably stop safely. On the other hand if it tightens itself, especially in a turn (where it's going to tighten), by the time you force it straight, you're probably going down. The bottom race has to be snug against the the lock nut--whether a ring or a nut.

    Obviously the bottom race needs to turn smoothly on the bearings, but not on the headtube, not on the threads. If it turns at all on the threads (the handlebar moves but the race doesn't) the bearings are immediately out of adjustment. You set and hold your adjustment with the bottom nut against the locknut.

    Not trying to be a hardnose here and certainly don't mean to offend, but I've seen headsets lock or bind up on both bikes and motorcycles--with bad outcomes (including a friend)-- mostly from improper installation. I guess I'm sorta' fanatical about these things.
  11. lennyharp

    lennyharp Member

    All the fine adjusting techniques will not keep a headset tight and adjusted if the top and bottom of the head tube are not parallel and at 90 degrees to the steering tube plane. A simple head milling will correct this if it is a problem. It is a job for a shop or you can order a head tube reaming and facing set for the right size head tube http://www.parktool.com

    A well made cheep bike and headset can work but I would not trust my life to a bargain at 25 + mph. I have ridden a number of well built, good quality cro moly bikes at up to 60 mph with little fear of it falling apart on me. That we are adding weight and vibration to these bikes calls for some wisdom in how well we build them and the quality of materials used. I looked for sturdy quality even when I raced, as the stresses are phenomenal on a machine that supports 10 times it's weight for the rider to bike ratio alone.
  12. kjparker

    kjparker Member

    BikeJohn is correct. All the nuts, apart from the top one, are circular. There is no tabbed washer.

    The notches I was referring to are in the sides of the washer, and appear to be for using a drift or similar to turn it. I have no way of tighteneing the lower nut against the upper nut, as the lower one, which is the one that goes against the bearings, only has a knurled outer surface, unless i put a set of multigrips on it, it can only be done up hand tight.

    i have just done it up again, this time tightened down everything, then backed off the slotted circular nut against the top locking nut, hopefully, this will last more than a few days before coming loose!
  13. bikejohn

    bikejohn New Member

    kj--just a silly question here...I noticed that you asked the forum in another thread about ball bearing sizes for headsets. I'm assuming that it was for this bike? And did you measure your old bearings and get the exact same size? (OK--2 silly questions).

    If perchance you had 5/32" bearings and you replaced them with 1/8" --or vice versa-- they'll never stay adjusted. They wont interchange. Just a thought.
  14. kjparker

    kjparker Member


    Not a stupid question, however yes I did end up measuring. I was hoping to order the new ones, keep riding, then replace them once they came.

    I ended up ordering both sizes (was only a few dollars extra for peace of mind), and installed the correct ones after measuring.