Play in an aheadset. Updated.

[Vetus Ossa]

Hello everybody, could use some advice please.
I have just bought a new (used) bike and am very happy with it.
So far I have found only one thing that needs fixing on it and that’s the headset.
Other than knowing it’s an aheadset, I am not familiar with them.
When you apply the front brake there is quite a lot of play.
I know how to adjust it and have tightened it down a fair way but it’s still there so assume its knackered.
Will it just be a case of replacing the bearings or am I likely to need to buy a whole aheadset.

[simonineaston]

I've not found Aheadsets partic. easy to adjust. I've adopted the tactic of leaning directly on the stem to preload the bearing. That way, I've removed play that had been there when I've adjusted them using the top cap. Don't know if that's acceptable behaviour, but it seems to work for me...

[peetee]

It will depend largely on the type of bearings fitted. They may be caged ball bearings or sealed units.
Caged will run on wearing surfaces on the cups that are pressed into the frame so replacement of the whole headset is necessary (Specialist tools are needed for this). It is rare for wear in loose headsets to be even around the circumference so replacing the bearings alone is not a cure in itself.
Sealed bearings are much more accommodating in that all wear is internal and the cups should not need replacement. However in extreme circumstances a loose headset can destroy these cups too.
Online video tutorial is a good way to learn how to dismantle and adjust aheadsets.

[roubaixtuesday]

Try an additional spacer on top, I'm struggling to explain precisely why but often solved this problem.

[geomannie]

Hello everybody, could use some advice please.
I have just bought a new (used) bike and am very happy with it.
So far I have found only one thing that needs fixing on it and that’s the headset.
Other than knowing it’s an aheadset, I am not familiar with them.
When you apply the front brake there is quite a lot of play.
I know how to adjust it and have tightened it down a fair way but it’s still there so assume its knackered.
Will it just be a case of replacing the bearings or am I likely to need to buy a whole aheadset.

Forgive me if I am teaching you to suck eggs, but you say you are not familiar with aheadsets. When you tightened the bearing load by tightening the top cap, you did loosen the stem clamp bolts first? I have seen folk ignore this step.

[slowster]

Remove the top cap and check how far below the top of the stem is the top of the steerer.

The top of the steerer must be a few millimetres or so below the top of the stem, otherwise when you tighten the top cap it will bottom out on the top of the steerer, at which point it can no longer remove play from the headset.

If that is the problem in your case, you need to add an extra spacer. The extra spacer can be added underneath the stem, or above it*.

* If the steerer is carbon, it is best to have the steerer protruding a few millimetres above the top of the stem, so that the stem does not clamp on the edge of the steerer, where it is weaker and might be crushed/damaged, but rather slightly lower down the steerer. Consequently with carbon steerers it is necessary to have a 5mm minimum spacer on top of the stem to allow the steerer to protrude above the stem. If it's a steel steerer this does not apply.

Edit - Photograph below from Park Tool website illustrates this, with the expansion plug (aka steerer bung) sitting on top of the carbon steerer and protruding above the stem, and around the steerer and the top of the expansion plug there is a 5mm (carbon fibre) spacer, the top of which is ~3mm higher than the top of the expansion plug.

https://www.parktool.com/blog/repair-he ... stallation

[Vetus Ossa]

Update.

Things haven’t improved. I tried to tighten it a tad more and something pulled away from the inside if the steerer tube and now it’s totally useless.
Not in the mood to look at it again today but guess I will have to strip the front end down tomorrow and have a good luck.
I don’t imagine its unrepairable, at least I hope not.

[DevonDamo]

(Re. your update: if I'm understanding you correctly, it sounds like the star nut has pulled out. Should be an easy fix - putting a suitably-sized bar down there and whacking it into position again with a mallet - or replacing if damaged.)

There are loads of possible causes here. In my case, I found a second hand mountain bike I'd bought was missing a component from the headset which meant that play couldn't be removed and you'd end up putting in a shed-load of forced trying to tighten it up, and it would still clunk when you applied the front brake, even though the steering had become seriously notchy because of all the excess torque through the top bolt. I only discovered the problem when I disassembled it. I started a thread on here about tracking down the missing component, which was a bevelled spacer thingy, but in the end found it easier and more cost-effective to just buy a new headset, including bearings, from Halfords. The bit that I was missing was this:

https://www.thebikefactory.co.uk/shop/c ... 88/option/

A mate of mine had a similar problem, but in his case the cause was that he'd replaced the top cap with a new one that included a bike-computer mount, and there was an interface problem between this new cap and the bolt.

So your best bet on getting any input via this forum would be to disassemble and get a photo of all the components to see if anyone can spot anything.

[Vetus Ossa]

(Re. your update: if I'm understanding you correctly, it sounds like the star nut has pulled out. Should be an easy fix - putting a suitably-sized bar down there and whacking it into position again with a mallet - or replacing if damaged.)

There are loads of possible causes here. In my case, I found a second hand mountain bike I'd bought was missing a component from the headset which meant that play couldn't be removed and you'd end up putting in a shed-load of forced trying to tighten it up, and it would still clunk when you applied the front brake, even though the steering had become seriously notchy because of all the excess torque through the top bolt. I only discovered the problem when I disassembled it. I started a thread on here about tracking down the missing component, which was a bevelled spacer thingy, but in the end found it easier and more cost-effective to just buy a new headset, including bearings, from Halfords. The bit that I was missing was this:

https://www.thebikefactory.co.uk/shop/c ... 88/option/

A mate of mine had a similar problem, but in his case the cause was that he'd replaced the top cap with a new one that included a bike-computer mount, and there was an interface problem between this new cap and the bolt.

So your best bet on getting any input via this forum would be to disassemble and get a photo of all the components to see if anyone can spot anything.

Thank you. Yes I will take some pic’s when I strip it down for a more expert opinion than mine.
I think I have managed to pull the threaded part of a star fanged nut out somehow. It’s not impossible I forgot to loosen the two stem bolts before I did but think I did
Anyway I have ordered a 1” sf nut and will set about what’s left of it in the steerer when I remove the forks.
On the plus side I will be able to have a look at the cups and bearings when I do.

[slowster]

Is it definitely a star fangled nut inside the steerer, not an expander plug?

Is the steerer tube steel, aluminium or carbon fibre (or, rarely, carbon fibre with an inner aluminium sleeve)?

[Vetus Ossa]

Is it definitely a star fangled nut inside the steerer, not an expander plug?

Is the steerer tube steel, aluminium or carbon fibre (or, rarely, carbon fibre with an inner aluminium sleeve)?

Good question, to which. I don’t know the answer, tbh I have never heard of an expander plug.
The forks are carbon and pretty sure the steerer tube is aluminium.
The forks are Kenesis wedge, and quite ancient I imagine.

[Jdsk]

Is it definitely a star fangled nut inside the steerer, not an expander plug?

Good question, to which. I don’t know the answer, tbh I have never heard of an expander plug.

"This article reviews installation and removal of "star-nuts" into threadless fork steering columns, as well as "expansion plug" installation.":
https://www.parktool.com/blog/repair-he ... stallation

Jonathan

[Vetus Ossa]

Just looked at the steerer tube, it’s steel.

[Vetus Ossa]

I think that's a star fangled nut...isn't it?
You may need to enlarge to see.

[jb]

I think your steerer tube is too long, try a thin spacer under the stem casting as suggested upthread. This will allow the top screw to pull the hole thing together and load the bearings thus removing the play.

After you have replaced the broken star washer and nut of course.