So, had a feeling that my start nut was slipping inside the steerer because of a weird creak. I knocked the old star nut through and fitted another. Creak came back after a few rides.
I figured that my method of (badly) fitting a star nut with a bolt, a hammer and some perseverance might be the issue.
Took the stem off and wound the bolt into the star nut. It was clearly not central.
I bought a star nut setting tool (cheap from amazon) and wow. That's easy!
I know the star nut was concentric when it went in. The creak came back so I whipped the stem off and fitted the setting tool onto the star nut and it had definitely slipped 4/5mm because the button bit that you hit on tool wasn't flush with the top.
I've smacked it back down but it doesn't feel like it's biting into the steerer properly when I nip up the topcap.
Whenever i remove the stem, I nip up the topcap bolt and usually stop after a few miles just to double check that there's no play and that everything is seated properly. I'm convinced that the star nut is slipping.
Are they all the same? There's load of brands that offer them. I've always figured they're probably from the same factory?
I'm also not totally convinced that the stem (Raceface Turbine R) clamps the steerer well enough at the specified torque . I'd it was the stem not clamping hard enough, I guess that would wiggle the SN out of the steerer? Surely a properly inserted SN should be able to back out though...
I think it's unlikely to be the star fangled nut making the creaking noise. It's only required to preload the headset, it doesn't hold it together, once the stembolts are all tightened up shouldn't be able to move. More likely something headset related or perhaps bar stem interface. As you mention maybe the stem isn't clamping properly if it has moved.
Did you use a new star fangled nut?
The star nut is only to set the bearing endfloat / preload. ~the stem clamp is what holds everything together. So your issue here is the stem slipping not the star nut. You should be able to remove the top cap completely after its all set up and nothing will move
I agree with TJ. But be aware bolt torques are usually quoted with a dry fastener, so if you've greased the bolts you're going to have to go to a higher torque.
As a mechanical engineer l'd recommend F.T. (****in' Tight)*
* Actually, I'd not. I Don't use a torque wrench on stems unless it is a particularly lightweight one or a carbon steerer, just go by sensible feel for a 4 or 5mm bolt with a normal length Allen key.
Is it a low stack stem or sat above the top of the steerer at all? Either could contribute to it trying to walk off.
You could try a expansion type plug, like a Hope Head Doctor, or similar. Some star nuts do slip, particularly if not set in straight to grip evenly all the way round.
I've had a couple of headsets which have required washers between the compression ring and top cover to stop creaking or play. Took me ages to find the cause on one bike. A Chris King headset is surely above suspicion.
definately not the star nut. something wrong with the headset assembly/installation.
could even be the headset cups moving in the frame.
or at the interface between stem and bars.
Yeah, the star nut should barely be under any tension, enough to take the play out of the headset bearings and that's that. Once the stem bolts are tightened you should be able to take the top cap out off and it'll make no difference to things. So I'd suggest it's not a star nut issue.
That leaves either the headset assembly (bearings moving? shims in the wrong order), a build issue (is the headtube ovalised at all) or a slipping stem (is it tightened to the right torque? If carbon, could you put some paste on it?).
It's not the star nut, it's the stem. So try some carbon paste between steerer and stem, or as a minimum clean the visible steerer with IPA before putting the stem on in case of any grease on there. Torque to spec, not well over. Some stems do have a poor grip even with that so if all that doesn't work, swap the star nut for a bung with a deep insertion length for maximum grip and all that should do it.
Agree it is not the function of the star nut to keep the stem on so not sure why swapping it to a bung is a good idea?
If cleaning, torquing etc,. doesn't solve it then trying another stem would be my first step.
I assume the entire stem clamp is in contact with the fork, not just a portion?
Agree it is not the function of the star nut to keep the stem on so not sure why swapping it to a bung is a good idea?
Because if the star nut is slipping under normal torque then there are alternative options that may help, whether or not it's contributing to other issues. Is the steerer steel? Star nuts don't work so well with those. Or carbon.
The theory behind a stem staying in place on its own is all fine and good, except in real world use things don't always work like that. In theory a Shimano type crank should stay on the spindle without the fixing bolt. In reality the tiny amount of preload provided by the fixing bolt can be what's preventing the crank working off. If a star nut is slipping it could be all it takes to allow a otherwise perfectly good stem to start moving.
I wrote a long reply earlier. Not idea where it's gone!
So, steerer pokes out the top of the stem.
No grease on the bolts, just a dab of blue loctite.
I've cleaned the steerer and stem with IPA.
Tried going over the recommended 5nM torque but not by a massive amount because the stem doesn't have a huge amount of material around the bolts. I've just tightened up until it felt tight.
Headset is integrated bearing so no cups to move.
Whenever I've removed the stem, I always stop after a couple of miles to check there's no play etc. It's a gradual thing over the course of a few rides. Last time, I backed the stem bolts off and nipped up the top cap bolt and it was better for a few miles but then it obviously loosened off again.
You're all right, it has to be the stem.
I've still got the original stem somewhere so I'll dig that out and see if it's any better.
If a star nut is slipping it could be all it takes to allow a otherwise perfectly good stem to start moving.
Completely disagree. That is not the function of the star nut and if it is moving then there is clearly an issue to be fixed (which has nothing to do with star nut). Also, a bung is not going to work any more effectively as a backstop than a star nut.
Headset is integrated bearing so no cups to move.
What's the frame, out of curiosity?
Imo some stems are poorer than others at gripping a steerer well. Could be amount of material, how it clamps etc. Yeah, changing the stem is the best answer. Another answer is adding a bit more resistance by swapping the star nut for a bung. For slipping lightweight xc stems, it can be just the small extra needed to make the system solid and resistant to slipping. Deep bungs with lots of surface area are very resistant to slipping and far better than a star nut with it's minimal contact area.
But generally, I have only had this issue with lightweight, not much material, xc stems. The beefier trail/enduro type stems are better, and usually with bigger bolts also torque up to 8Nm.
Completely disagree. That is not the function of the star nut and if it is moving then there is clearly an issue to be fixed (which has nothing to do with star nut).
As I wrote before, 'in theory' that's all very well and good. But it's not how things work in real life sometimes. You'd know this with enough experience working on bikes.
Also, a bung is not going to work any more effectively as a backstop than a star nut.
It can and does in many cases. Some expander types are considerably more effective than a star nut, easy to seat straight, and stay that way. A star nut isn't ideal for all situations.
What's the frame, out of curiosity?
It's an alloy Orbea Rise
In terms of bolt torque, this review has a pretty good picture of the steerer clamp. There's not much contact area with the steerer so maybe that's the issue
The other thing I considered is that although I can nip the top cap up enough to take out any obvious play, the SFN could be slipping so it's not actually giving enough compression in the headset? This is the first integrated headset I've used. My method is the same as it's always been which is wind the top cap bolt in until the play disappears and then nip it up slightly before tightening the stem.
I've noticed that I can't tighten it to the point where the steering goes stiff. I'm not sure if that's because the SN is slipping or whether IS headsets are less susceptible to binding. Maybe both?
When I try to tighten it further, resistance increases to a point but then it feels like something gives. Same as when you damage the thread or start to stretch a bolt. With how tight it is at that point though, there's no way I'm anywhere causing that kind of damage.
I'm fairly confident that the headset is assembled correctly. I'm going to take it all apart and play around with it and then stick a different stem on there.
Starnuts: Horrible, medieval things. Hope head doctor for me. Not perfect but better than butchering the steerer.
Now I've got that off my chest - it does sound like the stem. Maybe try a bit of carbon anti slip paste between it and the steerer - and do it up a bit tighter (but don't strip the threads)
My tuppence, if theres enough spacers above the steerer tube so the top cap isn't bottoming out, and the headset is installed correctly with no missing parts, then i'd change the stem. In fact, maybe change anyway if theres cracking nosies
Top cap shouldn't be holding anything on i'm not sure what bitmuddytoday is talking about, but i'm all ears if you fancy explaining.
When I try to tighten it further, resistance increases to a point but then it feels like something gives. Same as when you damage the thread or start to stretch a bolt.
It's not something as simple as an aluminium bolt with damaged threads, is it? I once had an undergauge fork steerer many years ago (Pace) but doubt that'd be an issue now.
It's not something as simple as an aluminium bolt with damaged threads, is it? I once had an undergauge fork steerer many years ago (Pace) but doubt that'd be an issue now.
Top cap bolt is steel as are the stem bolts. No damage to the threads on the stem or the bolts.
I don't think it's an underaozer steerer either as I had thebCSU replaced under warranty and I've had the same issue in both so unless Manitou have got serious QC issues then I reckon the steerer is good.
Carbon grip stuff had crossed my mind. I'm not so worried about stripping the threads on the stem, it's more cracking the clamp area of the stem that I'm worried about.
Top cap shouldn't be holding anything on i'm not sure what bitmuddytoday is talking about, but i'm all ears if you fancy explaining.
Really surprised I'm having to explain this, but okay. Firstly I didn't say the top cap would be holding anything on. The stem should indeed do this on its own. I suggested the downward force might help stop a stem working its way upwards. Once the top cap has been used to tighten all the spacers, stem, headset parts and head tube together you don't then undo the top cap, leave it on the work bench and go ride, do you? No, it's left in place providing some downward force. Therefore if the star nut doesn't slip but the stem wants to, creak by creak thousandth of a mm at a time over weeks and months, a small amount of compression from the top cap could be all that is required to stop that happening. It may not be the intended purpose of a star nut and top cap according to some on here but is a potential secondary benefit. If a expander that didn't slip fixed the issue then it has saved buying a new stem.
Not all stems are manufactured to precise tolerances, or immune to extreme forces of being wrenched up and down by the likes of singlespeeding, bike park use, or a bloater riding the bike. A long road stem or one with only a single steerer bolt would also be more prone to movement.
I actually agree the stem should be replaced, but also don't see the point of us all giving the same answer rather than thinking about things a little differently and suggesting other causes and solutions.
Once the top cap has been used to tighten all the spacers, stem, headset parts and head tube together you don't then undo the top cap, leave it on the work bench and go ride, do you? No, it's left in place providing some downward force.
You can if everything else is working fine. I ran a bike for weeks with no top cap
It may not be the intended purpose of a star nut and top cap according to some on here but is a potential secondary benefit.
Nope - the star nut will work its way out if the stem is slipping.
I actually agree the stem should be replaced, but also don't see the point of us all giving the same answer rather than thinking about things a little differently and suggesting other causes and solutions.
There is the right way to do things and the wrong way.
You can if everything else is working fine. I ran a bike for weeks with no top cap
What's your point? That you have a stem that stays put for a few weeks? Why don't you leave the top cap off permanently? And while you're at it take any fixing bolt out of your cranks? Do that on a few bikes for a reliable conclusion and report back after a year or two.
Nope - the star nut will work its way out if the stem is slipping.
You've failed to understand what I wrote, which was really fairly basic. I've explained it enough times now. There are situations where a small amount of preload down on the stem is all that is required to stop it working upwards. If the stem is completely buggered then obviously that won't be the case. If a star nut is slipping then there are other solutions that won't.
There is the right way to do things and the wrong way.
Wrong. It's important that differing ideas are put forward and that we don't all bleat the same thing like sheep. I stand by what I've posted in this thread.
I always back the top cap bolt off once the stem is done up properly and then just nip it up. Absolutely no pressure being applied, just keeping the top cap on. Which is basically only there for the same reason you have bar ends....
Do the stem up properly it should never move. Unless the stem is shit!
Op, try another stem and stop over tightening your top cap bolt.
The top cap does not stop the stem moving up. Its only there as a convenient way to set the preload / endfloat on the bearings. Once the bearing preload / endfloat is set and the stem tightened there should be no force at all on the top cap. to try to use it to stop a faulty stem moving up the steerer is putting forces on it its not designed for and its not its purpose.
The correct thing to do is to sort the issue - the stem slipping on the steerer.
The top cap does not stop the stem moving up. Its only there as a convenient way to set the preload / endfloat on the bearings. Once the bearing preload / endfloat is set and the stem tightened there should be no force at all on the top cap. to try to use it to stop a faulty stem moving up the steerer is putting forces on it its not designed for and its not its purpose.
It sounds like you've gone off the deep end in a further attempt to misunderstand what I wrote. I know full well what the top cap is intended for. However, leaving the top cap at the correct torque used to tighten everything up will in some cases prevent a stem from moving that otherwise might. Once again, not if it's completely buggered. It's really not that inconceivable for a stem to move a tiny bit over time, without it being considered faulty. Also, there is always force on the top cap unless it is completely loose, which it shouldn't be.
