Cycling UK Forum

I mean if I'm asking the question, the answer is probably "tighter".

I've got an old fashioned style quill stem type headset, and it keeps coming loose. The keyed washer doesn't have much of a key anymore, so I grip the bottom rig with pipe pliers, and tighten the nut. Even so, the with level of force, I'm not surprised that the washer key is kind of mashed, they aren't hard steel.

But it keeps coming loose after a few weeks. Any recommendations?

Currently I'm carrying the pliers around in my bag...

The “keyed washer” thing is a bit of a gesture really. Even if the whole headset, fork thread, etc. are all in first class condition, you need to do the locknut pretty tight for the thing not to loosen off. I usually ended up holding the adjusting cup in either a proper headset spanner or a really big adjustable spanner; but it needs to be a good make where the jaws are properly parallel.
If the thread is a bit worn or the headset doesn’t seat properly in the frame then it’s going to come loose.
You might be able to find a headset where the adjustable cup has a bolt which nips up a clamp on the fork steerer thread, or a “repair” headset with a substitute steerer thread; I might have something in my shed.
If the fork thread is good, it may just need a new headset.

You could try thread lock as a last resort.

Tange Seiki says in the following document, which SJS Cycles has on its website:

https://www.sjscycles.com/Instructions/ ... ctions.pdf

(linked from here: https://www.sjscycles.co.uk/headsets/ta ... ack-height)

… to tighten the lock nut to 300–400 kg/cm2, which I’d just call kgfcm. Divide by about 10 to convert to Nm, so 30–40 Nm.

That is indeed quite a lot. Approaching pedal-installation torque.

By the way, I use a 10-inch Knipex pliers wrench for this job (and many others for which I used to use an adjustable spanner). It does a great job of clamping down hard on such nut flats to prevent marring their corners or slipping. This sort:

https://www.knipex.com/products/pipe-an ... ol/8603250

commonly, the first part to start wearing badly (apart from your patience) in such circumstances is the steerer, where the adjusting race screws onto it. Provided you still have something there (not much is required) all is not yet lost. If the adjusting race is a bad fit on the steerer (too loose) then the trick is to improve it by whatever means necessary. Commonly the best solution is to apply a few turns of PTFE tape to the steerer; be sure to apply it correctly, ie. on a RH thread (so CW to tighten) the tape should also be wound on CW.
Obviously if you use too much tape,you won't be able to move the adjusting race, even with the aid of a very big spanner. However, because the tape does not easily/immediately fill the available space, prior to complete immobility there is quite an extended phase in which the adjusting race can still be turned, albeit perhaps with the help of a big spanner. It is useful to know how many turns constitutes 'too much' because as this limit is approached, the required locknut torque goes down. In fact if you get it just right, you may not need a locknut at all. Very often the critical point can be easily/accurately determined using a variant of the 'tapered wind' procedure. In this, PTFE tape is applied in a LH helix, such that each successive CW turn is applied to the right of the one immediately prior, by a fixed increment. For example if the tape is 12 thread pitches wide, winding 12 turns on, each set 1 thread pitch rightwards of the one previous, will result in a tapered wind of 0-12 layers thickness. If you then try to screw the adjusting race on, the point at which it becomes immobile (even with a big spanner) is the critical point, when the PTFE layer is sufficiently thick to fill the thread clearance entirely. Normally it is possible to use 1 or 2 turns less than this along the entire length of the thread.
PTFE tape is almost ideal here, being thin, easy to apply/remove, cheap, low friction, a contrasting colour to most metalwork, of uniform thickness, and widely available. Because the steerer is thin-walled and might collapse, it is a very good idea to keep something exactly 7/8" diameter inside it whenever high levels of torque are being applied.

btw it is important that the flange that is atop most locknuts does not bottom out on a slightly overly long steerer. If it does this, all locknutting action is lost, but this may be easily remedied by use of a file, or spacers.

What make of headset? Photos might help. They can be very good if the problems described by others do not apply, but the good ones have spanner flats on both nuts.

Thanks all for the input!

The headset brand is definitely "miscellaneous". Only the upper bit has flats, so I've been using large (Bacho) pipe pliers on the ring and a decent adjustable spanner on the upper bit.

Based on the torque numbers I was not going tight enough (though that's a bit tricky without flats). I'll try cranking it up properly and see if that works. If not I'll work through the other solutions.

For now I'll keep the big pliers in my pannier bag

They're lighter than the spanner anyway and I've got that in case I get a puncture.

I might consider an upgrade to one with flats on both. Not because flats on both are in themselves the answer, so much as their being a marker of a decent brand that will be more likely to stay put once tightened.

Again though, no brand is going to resolve the problems described above by others. They need to be addressed directly.

Looking now like it's most likely to be not tightened properly, an second choice maybe a new headset. Steerer tube thread is very fresh (the forks are pretty new). It's also a slightly oddball size, or not what I was expecting at any rate. Also the head tube is bigger than expected, so headsets are a bit rarer (the one my LBS gave me was too small).

Samuel D wrote: ↑22 Oct 2024, 2:46pm ...

By the way, I use a 10-inch Knipex pliers wrench for this job (and many others for which I used to use an adjustable spanner). It does a great job of clamping down hard on such nut flats to prevent marring their corners or slipping. This sort:

https://www.knipex.com/products/pipe-an ... ol/8603250

Thanks for that. Knipex tools are good and of course not cheap. I should replace my old Crescent adjustable spanner and use the Vise-Grip less. Off to Bauhaus...

mister_ed wrote: ↑24 Oct 2024, 9:06am... the head tube is bigger than expected....

the most common size for threaded headsets is 30.2mm ID for the head tube, but there are some that use a 30.0mm ID head tube. I think it is OK to use a little adhesive (eg. epoxy resin) to hold loose-fitting cups in place. The first time I did this, I thought it was probably a bodge. However, being almost stress-free, I now consider it to be an improvement. In fact I consider most interference fits to be fairly barbaric.

If a headset won't stay tight, it often means the head tube and fork crown seat want facing.

Brucey wrote: ↑24 Oct 2024, 7:28pm

mister_ed wrote: ↑24 Oct 2024, 9:06am... the head tube is bigger than expected....

the most common size for threaded headsets is 30.2mm ID for the head tube, but there are some that use a 30.0mm ID head tube. I think it is OK to use a little adhesive (eg. epoxy resin) to hold loose-fitting cups in place. The first time I did this, I thought it was probably a bodge. However, being almost stress-free, I now consider it to be an improvement. In fact I consider most interference fits to be fairly barbaric.

A beer can shim is better, as it doesn't affect removability.

Over the years I have found headset loosening in threaded headsets to be a perennial curse.
I think it's due to the fact that due to being vertically challenged I have always had smaller frames and hence shorter head tubes.

I found a solution when browsing at a jumble and found a cheapish Chinese made headset with three grub screws in the top locknut.
When the headset was satisfactorily adjusted the grub screws were tightened onto the steerer effectively preventing movement.

I copied this and drilled and tapped the locknut on a stronglight headset using 3mm grub screws - this worked well.

All in all though I prefer the crude but effective "aheadset" which I find very satisfactory in use.

Hi, I had a similar problem this summer with a 1” threaded headset on an old MTB. A 1996 Raleigh. It is used off road and has had a good innings, which probably explains why the fork steerer threads were a bit knackered.

Luckily I had the option to saw off 5-10mm from the fork steerer. This exposed the headset locknut to better condition threads, which seems to have fixed the problem.
I didn’t know of Brucey’s PTFE tape trick, so will try that first next time.

On another frame I tried a different solution. I filed flat some fork steerer threads and used a specially shaped spacer. It has worked really well but it was quite expensive all in (delivery charges, import charges too).