Movement in the headset - after every ride (SOLVED - PAGE 2 UPDATE)

Secteur

Hi folks, I'm a fairly accomplished / competent amateur mechanic, but just wondered if I could run this by you guys.

Towards the end of every ride, I notice slight movement in the headset under braking.

Carbon steerer, aluminium stem (both stock).

3 year old bike, and only recently been doing this. Prior I'd only need tighten up the bearing pre-load perhaps every month or two.

Once home, I loosen the stem bolts, nip up the top cap bolt and re-tighten the stem bolts using a torque wrench.

Again, the following ride, after an hour or so, play starts to develop under breaking, and the cycle continues.

I use after-market titanium bolts with copper anti-seize grease and torque to 6.5N (suggested range 5-6N as printed on the stem).

Does the fact that I am using titanium bolts, or the fact that I am using copper grease mean I should be using a higher torque?

The aluminium stem clamps to the carbon steerer tube "dry" - it occurred to me today that perhaps I should use some carbon assembly paste at the interface?

Or could this be indicative of a problem elsewhere?

Thanks.

jgsi

Undo the bars and remove the bung... get some isopropyl cleaning fluid and clean the inside of the steerer tube and the bung itself... any trace of grease etc can cause the thing to slip during a ride and cause the movement in the headset.... it's one thing to try at least.

Secteur

Good idea - I'll do that, as well as my idea of using assembly paste. I'll wait a couple of days before looking at it though to see if any other additional advice is forthcoming. Thanks!

imposter2.0

Sounds like the top cap is not tightening down properly - ie it may be tightening on the top of the steerer, rather than the stem itself. Add another spacer over the stem.

Secteur

Imposter wrote:

Sounds like the top cap is not tightening down properly - ie it may be tightening on the top of the steerer, rather than the stem itself. Add another spacer over the stem.

Ok, will certainly check that, but the initial tighten and first hour or so of the ride it's "tight & tidy", with just the right amount of bearing pre-load. It seems to loosen after that, but never gets to rattling - just that very slight knocking under front breaking; felt rather than heard.

cycleclinic

Some bungs just dont grip the steerer properly as well (if it is a new setup). I had the same issue once on my sannino can remember how I resolved it though but I did suspect traces of grease and I cleaned everything up as suggested. Also some top caps are deep and you sometimes need more than the 3mm gap you normally need between the top of the steerer and the top of the spacer. Campagnolo record 1" top caps are a prime example of this.

6wheels

If everything adjusts correctly, it's probably lack of grip between stem and steerer tube. Anodising will create quite a 'slippery' surface, so, with 180 grit emery give the inside of the stem a good rub to break the anodising and also do the same with the steerer but with a very fine grit (600 grit or even steel wool). You're not trying to change the size of either, just breaking the surface. HTH

mfin

Either the expander bung is shifting ...or, try putting an extra shim under the top cap like this if the conical headset topcap is possibly touching the steerer. In cases where the latter is happening the behaviour you are getting is quite common.

https://www.mcconveycycles.com/0-4mm-headset-shim-spacer.html?gclid=CPi7ndLh388CFeoW0wodRjcJUw

You'll need to find one in 1 1/8 for a standard steerer column, not in stock on that link, search for a "headset shim washer".

(most bikes normally need one of those, I have one bike that needs two of these to avoid what you are finding is happening).

You should not need to use any compounds on the steerer tube for stem clamping, that's not needed, but you must make sure that the expander bung is not shifting and creeping upwards.

As above too, you must make sure there is enough spacer showing above the top of the expander bung otherwise the top cap will be pulled down by the bolt and foul the top of the expander bung.

Secteur

Great advice all, thanks!

When I get at it (hopefully tomorrow night) i''I'll report back.

sungod

the bung slipping or not should make no difference, it's the stem that must hold the steerer in place, not the bung/top cap

either the stem is slipping, or the bearings/headtube/steerer/stem have a problem, might be worth stripping it all out for a good look, corrosion, cracks, wear - it's been ok for three years, it seems something has changed, find out what

does the bung extend within the steerer to cover the full length that the stem clamps? if not, i'd consider getting a bung that does; as mentioned above, if the top cap is fouling on the bung it'll prevent bearing preload, but as it's been ok previously it'd be odd if this were the problem now

degrease steerer and inside of stem, adjust preload (2 Nm on the top cap bolt should be plenty), clamp

grease on the bolts will *reduce* the torque needed to reach a given clamping force

i wouldn't use carbon paste on the steerer as if it gets washed down into the bearings they'll get gritty

pilot_pete

sungod wrote:

the bung slipping or not should make no difference, it's the stem that must hold the steerer in place, not the bung/top cap

either the stem is slipping, or the bearings/headtube/steerer/stem have a problem

You reckon? I disagree. I don't think the stem is slipping. If it were loose you would be able to move the bars left or right whilst holding the front wheel. The stem can only grip the steerer where it is set by the top cap preload.

Bearings a fault? Pretty obvious if they were - they would be rough and graunchy if you tightened the preload and they were collapsing. If they hadn't been pressed fully in (if indeed they are pressed into the frame) then this could lead to play. But, the play would manifest itself due to them moving further into their seating, thus after a couple of 'resets' this should be eliminated.

It would be pretty obvious if the headtube had a problem upon inspection. This is highly unlikely, as is the steerer itself being the problem - simply inspect it.

What problem could the stem have? Crack? Stripped thread? Again, easy to ascertain with an inspection.

The problem sounds like the preload is not being set correctly before the stem bolts are tightened. This could be due to the bung slipping as the top cap is nipped up or the top cap is being tightened against the top of the steerer thus not applying the load to the bearings.

If the bung is slipping it would appear that preload has been set, but it will not have been. This will lead to the inevitable play once the bike is ridden and everything settles. Sorting out the preload is where I think your solution lies.

PP

Secteur

Ended up having a play just now and I *think* the bung is slipping - a bit more inspection required tomorrow, but the stem clamp seems very tight with no movement.

I am not sure exactly how the bung slipping is directly causing my issue, if indeed it is that, but I have a feeling it is this just from inspecting all the parts.

It's an aftermarket bung, but is lined up internally and been problem free until now. On inspection it looks intact with no obvious wear, but it just won't seat as perfectly as I'd like, and something tells me it's not doing it's job perfectly.

Anyway, I have ordered a new headset (including new manufacturers compression bung) as the bearings are a couple of years old, so I will do a deep clean, inspection and re-fit and then take it from there.

Thanks folks.

Secteur

PS there's no fouling of the top cap on the steerer tube - I have checked and double checked that.

cycleclinic

Stem slipping would do it. I remember now that was the problem i had. Carbon padte solved it.

sungod

Pilot Pete wrote:

sungod wrote:

the bung slipping or not should make no difference, it's the stem that must hold the steerer in place, not the bung/top cap

either the stem is slipping, or the bearings/headtube/steerer/stem have a problem

You reckon? I disagree. I don't think the stem is slipping. If it were loose you would be able to move the bars left or right whilst holding the front wheel. The stem can only grip the steerer where it is set by the top cap preload.

this is incorrect

unless the steerer is stretching, or the headtube/bearings/stem compressing, the stem must be slipping

it does not need to be noticeably "loose" to slip, loading during riding could cause it to creep, vertical loading is far higher than any likely rotational loading, a loose bung would compound this

but the issue would still be that the stem is slipping, not that the bung is...

once preload is set and the stem clamped, the top cap's function is to fill in the hole and cosmetics, a correctly clamped stem can be ridded perfectly safely without the top cap present

The Rookie

Try steel bolts, Ti has a lower Youngs modulus than steel so under the same load they stretch more and that may be just enough for your stem to move, that said I'm using Ti without issues (alloy steerer).

With all the above, the top cap and compression bung is meaningless, once the stem is done up, you can remove the top cap and ride a bike, the steerer clamp should be doing all of the job.

I'd try a little carbon gripper paste on the, erm, carbon steerer as well.

Are you sure the headset is loose and you're not picking up play from somewhere else, how are you testing it?

svetty

If there is wear in the bearings this could be enough that the upper bearing cover isn't clearing the head tube fully. I'd remove the head set, clean and re-grease the bearings (replace if worn) and then add a shim under the upper bearing cover. Re-set the preload, making sure the bung is correctly seated, and make sure stem:steerer interface is clean.

Another possibility is that the crown race is cracked/compressing slightly - I'd check the whole fork.....

Semantik

You will go on forever trying to regrease,retighten everything,almost certainly with the same inevitable result.
Been there, done that.
In the end I bought and fitted a new, complete quality integrated headset to replace the cheap, unbranded, one which had seen little use, so was theoretically still serviceable. After this I never had any such problems again.
FSA Orbit CE has proven faultless in 12 months over 2000 commuting miles

bungalballs

I agree with Rookie; titanium has a lower stiffness than steel and can effectively 'stretch'; titanium skewers can do the same if over tightened, though I would add that the first thing I would be doing is removing the stem bolts completely and checking for any signs of distortion or damage. Unlikely, but better safe than sorry.

Also, how are you checking for play;? If you are using the method of grabbing the front brake and 'rocking' the bike, it could be play elsewhere.

dee4life2005

What if the split ring that is used center the steerer isn't fully seated correctly against the bearing. This could result in rocking the bike in one direction appearing to indicate the bearing is preloaded correctly, however if it's not seated correctly then this could in theory move slightly when the bike is used either by rotating with bars or through a jolt from riding over potholes. If this happened it could cause a very slight change to the bearing pre-load mid-ride. I'm sure I had just this scenario that caused a bit of head scratching over the course of a few rides until I stripped the headset back and rebuilt it.

Secteur

HI, thanks for all the excellent replies.

Well, my technique for testing is indeed holding the brakes and rocking the bike, but there is very definite (if small) movement of the fork on the headtube - you can actually see and feel it, and it causes the fresh grease applied last night to ooze out.

This was in the garage straight after tightening, not after an hours riding as before, so perhaps something has broken somewhere.

Something has definitely changed.

I have ordered a new headset and will strip and inspect the whole thing when it arrives, including the headtube, fork/steerer etc. Pulling it all apart properly will help as I am currently dabbling without removing the front brake meaning I cant fully remove the steerer to inspect it.

My only concern is can I ride it tomorrow / Wednesday as I usually do mid-week, or am I on the couch! I will have to really look at it tonight and make a judgement.

Incidentally, I note that the upper bearing has a split ring spacer, but the bottom bearing seems to just fit into the lower headtube with no other components local to this - no crown race, nothing. I believe this isnt unusual, but just wonder if perhaps something is missing from when it was built up new - however this being 3 mostly problem free years ago, I doubt it, but the bike came with a "bag of bits" on the handlebars when new, which included several small spacers and a crown race which all look to be part of a headset.

All that said, intense googling leads me to believe the lower bearing doesnt require any spacers / races, though even cannondales own technical drawing are remarkably non-specific and lack detail on the exact headset set up.

The Rookie

Depends on what headset you have, which is?

Its usual fro the top compression ring to be split, ideally the split should face left or right (point of lowest load) although in reality it makes no odds.

Where was the grease put that is coming out there shouldn't be any grease there unless the cartridge bearing itself has failed (and hence it's seals).

Secteur

This is the most technical drawing cannondale seem to do of the headset, and assuming this is a complete drawing, these are the only parts (not including headset spacers above).



As for the grease - I liberally applied aquaproof paste around the bearing before and after slotting it into the headtube to help keep grit out - have always done this as I find it significantly prolongs the life of the bearings. It was working out of the gap between headtube and fork at top and bottom of the headtube due to the slight but noticeably abnormal movement there.

My gut seems to be leaning towards a faulty or worn compression bung which doesn't seem to be tightening and pre-loading the bearings properly. It's the only part of the whole set up I am not confident about on initial inspection - all other parts seem "tight" and well fitted etc, but the compression bung is awkward and problematic to fit - it just feels to me that the problem somehow lies here.

In any case, as above, I have ordered a whole new headset and bung / integrated top cap - manufacuters own - so should resolve the problem with a full strip down and re build, assuming no cracks etc to the frame / fork.

I may also replace the Ti stem bolts with steel ones (I only changed them as they had rusted and the Ti ones were a nice blue colour!) but at £7 a set from wiggle, I will see if the new headset solves the problem first (but will clean and examine the bolts anyway).

Secteur

OK! Problem identified & solved!

This has been bugging me all day; the fact that I have never been able to get the compression bung to fit in a satisfactory and solid way - it is the only piece of the puzzle that I haven't been confident about.

So I got home and took it out and ha a really good look at it and how it works - well, I'm a bit of a fool because upto now I had simply been sliding it into position inside the steerer tube where it sat snugly but not firmly. I didn't realise that there was a hidden hex shaped hole inside it, which when turned with a long Allen key, expanded the bung to fit tightly inside the steerer.

This hex key is very well "hidden" and not obvious until you really look at and think about how the bung works. The topcap bolt lies through the hex shaped gap, so I never realised it wasn't just a hollow part of the bung.

Anyway, once solidly seated and expanded tightly against the wall of the steerer tube, the topcap bolt had something to pull against which wasn't going to slip, and the whole thing has come together very nicely, and now enables me to really feather the bearing pre-load perfectly - before it was pretty sloppy, but I thought nothing of it.

So, the problem was the compression bung slipping.

Thanks to everyone for the input and advice, and well done that man above who first confidently said it was the bung - you were right and you made me really think about the problem and solve it!

pilot_pete

Do they do a smug smilie? apologies gratefully accepted from all the nay sayers who insisted it must be the stem slipping.

PP

p.s. that was a joke, don't get offended anyone. Glad to hear you got it sorted secteur.

sungod

Pilot Pete wrote:

Do they do a smug smilie? apologies gratefully accepted from all the nay sayers who insisted it must be the stem slipping.

PP

p.s. that was a joke, don't get offended anyone. Glad to hear you got it sorted secteur.

nope, because the top-cap is immaterial

if the headset unloads, the stem is slipping, otherwise the headset would stay loaded

relying on the top cap to hold it down is bodging it

btw i'm not offended nor apologetic, just concerned that the op thinks relying on the top cap to hold a safety critical component in place is a solution

6wheels

Agree with sungod, in fact my Canyon has the Acronis headset and that doesn't use a compression bung.

Main thing is...it's all good.

jermas

You're correct that the bung doesn't hold the stem secure when the stem has been tightened BUT the problem the OP was encountering, was that the bung was being pulled up during the installation, therefore no pre-load was being applied to the stem/headset bearings. I.E Pilot pete was correct.

Secteur

jermas wrote:

You're correct that the bung doesn't hold the stem secure when the stem has been tightened BUT the problem the OP was encountering, was that the bung was being pulled up during the installation, therefore no pre-load was being applied to the stem/headset bearings. I.E Pilot pete was correct.

This.

And the OP (me!) isn't relying on the top cap alone to hold it all together. I do appreciate your time and input (genuinely!) but maybe go back and read all the posts again (if you still have the will to live !!).

Anyway, thanks again all!

StillGoing

Still doesn't make sense. The top cap merely preloads on top of the stem. If the stem is tightened correctly, the steerer still shouldn't come loose even if the top cap is then removed as the stem is holding everything in place.

daniel_b

Secteur wrote:

OK! Problem identified & solved!

This has been bugging me all day; the fact that I have never been able to get the compression bung to fit in a satisfactory and solid way - it is the only piece of the puzzle that I haven't been confident about.

So I got home and took it out and ha a really good look at it and how it works - well, I'm a bit of a fool because upto now I had simply been sliding it into position inside the steerer tube where it sat snugly but not firmly. I didn't realise that there was a hidden hex shaped hole inside it, which when turned with a long Allen key, expanded the bung to fit tightly inside the steerer.

This hex key is very well "hidden" and not obvious until you really look at and think about how the bung works. The topcap bolt lies through the hex shaped gap, so I never realised it wasn't just a hollow part of the bung.

Anyway, once solidly seated and expanded tightly against the wall of the steerer tube, the topcap bolt had something to pull against which wasn't going to slip, and the whole thing has come together very nicely, and now enables me to really feather the bearing pre-load perfectly - before it was pretty sloppy, but I thought nothing of it.

So, the problem was the compression bung slipping.

Thanks to everyone for the input and advice, and well done that man above who first confidently said it was the bung - you were right and you made me really think about the problem and solve it!

Ah that old gem, the one on my Scott had that issue until I found an online article that said to tighten it to 8nm - since i have done that, it has not budged.
Glad you have it sorted anyway.

I suspect the reason it seems fine to start with, is that it is tight, but then as you ride, the vibrations go through the frame, and the bung succumbs to the pull from above and slides up the steerer, as it's not tight enough within the headtube.