Headset keeps coming loose

Yacoby

So my headset keeps coming loose, as in done up properly (by someone other than me, stem done up with a torque wrench etc), and within a couple of hours of riding it has come lose.

Took it to a bike shop, and they said basically (I think):
Bit of wear on the outside of the cartridge bearings indicating that they may have been moving.

Their suggestion to replace the bearings as something that may work (They were uncertain about that, but it was a suggestion). I didn't ask at the time but now it occurs to me that the cups may be worn as well as I think they are both steel.

The current headset is a FSA Orbit ZS (So 1.5 lower, 1 18 upper)

My question is, does it sound a reasonable assumption that replacing the bearings would work? The reason I ask is that they are ridiculously stupidly expensive (£20+ for both). As in they seem most of the way to a new headset.

Chunkers1980

No. Do the stem up tighter and once that's tight make sure to top cap is tight too as a double check measure.

cooldad

Maybe do it yourself so you know it's done. Always assume everyone else is an idiot. It's pretty close to true anyway.

Yacoby

I tend to make the assumption that the biggest problem is me. *shrugs* Maybe it is shops getting the torque wrong IDK. I know I have a habit of undertightening things but I would have hoped shops could get it about right. So the stem bolts are now at 6Nm with a torque wrench that is relatively new and so should be fairly accurate.

I'll see how that goes.

cooldad

Headsets 'settle' so need checking once or twice (or regularly TBH) after fitting. I've never used a torque wrench on a bike - just make things tight enough and job's done.

Yacoby

cooldad wrote:

I've never used a torque wrench on a bike - just make things tight enough and job's done.

Tight enough to get the job done is hard when you don't know how much that is. I know I undertighten stuff a lot so now in most cases I do it up by hand and then take a torque wrench to see how much I need to add.

Give it a year and I probably won't need the torque wrench and be able to get it good enough by feel alone.

cooldad

It's a zen thing. Become one with the bolt, young grasshopper.

felix.london

My technique is that I tighten up bolts as tight as I can :shock: ...holding the short end of an L-shaped allen key*

*this might not work if you're Superman

iDad

i had a similar issue recently and through messing around with it too much i managed to pull the Star nut through and f*ck it up.
since getting the new star nut it felt ok but after a long ride at the weekend it went loose again....however this time i noticed that the top cap was tight but the spacer below was loose.
further checking and i spotted that the top cap was clamping against the steerer tube before clamping the spacer/stem.
i found myself a slightly thicker spacer and now the headset is as it should be again. 41miles XC Friday and 24 last night and still no movement :-)

cooldad

felix.london wrote:

My technique is that I tighten up bolts as tight as I can :shock: ...holding the short end of an L-shaped allen key*

*this might not work if you're Superman

I have a finger rule:
1 finger - teeny tiny bolts
2 fingers - small bolts
etc up to
Whole body - jump around on the wheelbrace loosening nuts some gorilla sized mong with a maladjusted air wrench put on.

ashleygreen

Type how to tighten headset on you tube and there good videos.

Hope this helps.

Ash

The Rookie

Make sure the steerer and inside of the stem aren't greased.

Don't do the topcap nut tighter, that just preloads the bearings too much.

If the bearing housing for the cartridge bearing is worn (big if) then it means an all new bearing setup.

thelonegroover

How old is the bike and what sort of life has it had?
6 Nm is not actually very tight, even for stem bolts.
Loosen the stem bolts and tearer top nut, check spacers are seated correctly, retighten top nut to preload the stearer. Retighten s the stem bolts. You should then be able to loosen the top nut and check the spacers again. Don't forget to tighten the top nut before actually riding though.

The Rookie

You can remove the top cap totally once the stem is done up, it is that and only that that maintains the preload after all.

Chunkers1980

But if I was having issues with the stem slipping I'd leave it on and tight.

The Rookie

IF the stem is slipping, maybe, but then it will usually rotate as well, so I'm not convinced it is slipping....

thelonegroover

Chunkers1980 wrote:

But if I was having issues with the stem slipping I'd leave it on and tight.

Surely, if your having issues with the stem slipping, it's not tight!
The point is, it's the stem to steerer bolts not the top preload bolt that holds the stem on.

Chunkers1980

What are you talking about.

The Rookie

Bikes, what were YOU talking about?

supersonic

The top cap is a bearing adjuster, which can only adjust the bearings when the stem is loose, and the stem overlaps the top of the steerer by a few mm.

It does not keep the stem on tight, it is purely an adjuster. Once adjusted, the stem is tightened using its own bolts, which keeps the adjustment in place and, of course, the stem in place.

Never tighten the top cap bolt with the stem tightened, all it does is pull the SFN up.