Damn headset/stem coming loose

Bicycling
1

Anyone know how to stop a headset from coming loose? It seems every time I ride Whopper or another drop’y trail my headset comes loose. It’s been happening since I built my new bike, Manitou Minute Expert 130mm fork, Giant Connect stem and Chris King headset. I’m at kind of a loss on how to fix it, what is happening is that it seems that after some hard riding the stem is being pushed up allowing the headset to come loose, the stem itself is still tight as I can’t move it side to side but you get the typical clunk clunk from the headset.

First time it happened I took it all apart, cleaned it and reassembled, made sure things were tight. Rode whopper and half way through I noticed it had come loose.

Second time I took it all apart, lightly sanded the steer tube and inside of the stem hoping to rough it up a bit for better grip, nope still came loose.

Third time I put a pop can shim in, and tightened the bejesus out of it. Today it came loose again, and now I don’t know what to do about it, I’ve never had a headset / stem come loose before like this.

Any ideas?

2

possibly put another small spacer ring in between the top cap and stem?

3

My first thought was that your headset cups or fork race weren’t seated properly, but if that was the case it would probably only happen once. Maybe try a different stem to eliminate that variable.

4

Headsets shouldn’t keep coming loose. And you shouldn’t have to over tighten the stem. Did you seat the crown race with the proper tool? If not, or if it didn’t get driven down hard enough, it could take a time or two to adjust it. Something that can happen is the steer tube can migrate out of the crown. Look under the crown and check, as well as the gap at the top cap. If you didn’t need anymore spacers at first but now you do, either the race finally seated or you have bigger issues. I wouldn’t recommend sanding the steer tube or the stem as this can remove enough material to reduce friction as well as polish the surface. If it just ends up being the stem slipping you can add some friction paste to it. It’s originally made for clamping carbon parts but it works great on other materials as well. Perfect for seatposts that keep creeping down. Etc. I can give you a few packs at the shop.

5

Could maybe be your star nut is slipping?

6

Thanks everybody, I think its been figured it out, I hope, :stuck_out_tongue: .

Looks like the stem was locking on to the Chris King top cap and not the steer tube (causing only the lower stem bolt to grip the steer tube), I noticed when I tried to take the top cap off last night and it was locked in tight, I had to loosen the top stem bolt to get the top cap off, normally I had been loosening the stem bolts first so I hadn’t noticed before.

I stuck a 3mm headset spacer between the stem and top cap to stop the stem clamping down on it instead of the steer tube. It’s weird, I’ve had this headset for 12 years and this is the first time this has happened, though only the third stem it’s been installed with.

We’ll see what happend next ride.

7

What do i win??

8

Well, I false alarm I guess. The story continues. Le sigh.

All seemed good until I rode Fight Trail, about 1.5km in I could hear the creaking of a headset coming loose, so I stop and check and sure enough rock it back and forth and she’d started working herself apart. So loosen the bolts and go to tighten the stem… again… and the bolt pulls through and rips the threads out. Well, I kinda saw that coming with all the tightening and loosening and over tightening.

So I go down to MEC which is the only place that’s still open that I can buy a stem at and pick up a Race Face Ride stem, not a high end stem by any means but I figured it’d get the job done. I put it on the bike, tighten the bolts with a torque wrench to 70in-lbs and go ride Fight trail again, didn’t seem to come loose this time.

Fast forward to last weekend I ride the Anima Mundi trails in the valley, and half way through the trails it comes loose again, so I re-tighten everything and finish the ride without it happening again.

So I decided to try the carbon installation paste. I picked some up and reinstalled the stem with it, hoping it would work. Tonight I rode whopper, and got all the way half way through “the other side” before it started to come loose again. When I tried to tighten it again one of the bolts broke, I didn’t even try to tighten it that tight, cheap stem cheap bolts I guess. I rode back out carefully, second stem in a month broken.

Shortly after I bought the Race Face stem I put an order in for a 60mm Hussefelt stem, bigger stem, bigger bolts and much higher torque rating (90in-lbs) and steer tube grip. That should arrive early this week and hopefully put an end to all of this.

I really don’t know what to do if the Hussefelt stem does not solve this. I am hoping that using XC stems on a bike with a slacker head angle is causing this and that a heavier freeride stem will solve that. I am not a heavy rider, I only weight 130lbs. Most of my bike parts over the years have died because they wear out or just get too old.

This is the setup in question.

9

Have you tried a new start nut?

10

Feel free to correct me here, but the stem bolts don’t directly affect headset adjustment. That’s done through the top bolt through the cap. The cap pulls the stem down onto the headset. Keep the stem bolts relatively loose until you get the headset adjusted, then tighten them. The stem shouldn’t pull up off the headset even if the stem bolts loosen up, although the handlebar might go crooked. Tighten the top bolt until the steering feels a bit “notchy” and then loosen until the notchiness just goes away. If it keeps coming loose, I’d go with Pepperjester - try a new star nut inside the head tube. The top bolt goes through the star nut, and if it’s slipping, it’ll pull out, loosening your headset. Again, headset experts feel free to correct me.

11

Unfortunately that is not the job of the top cap. The top cap is only there to preload the headset before the stem bolts are tightened. You should be able to remove the top cap on a properly set up system and have no issues. The star nut is only held in by friction and would not withstand the force required to keep the stem on if your stem bolts were loosened. Believe me I wish that was the problem.

12

It would seem you are playing an elimination game with a problem like this.

Was this headset always with this frame? If so, was anything changed prior to it loosening up? (i.e. bearings, top cap, fork)

Do you have another headset or extra pieces to swap out for testing purposes? Tedious, yes, but effective.

13

[quote=“riderx”]It would seem you are playing an elimination game with a problem like this.

Was this headset always with this frame? If so, was anything changed prior to it loosening up? (i.e. bearings, top cap, fork)

Do you have another headset or extra pieces to swap out for testing purposes? Tedious, yes, but effective.[/quote]

The headset has been on three other frames before, but it’s a King headset so it lasts without issue. The cups are in the frame tight and the bearings feel fine, the crown race is seated and on tight as well. I do have another headset, but I’d avoid changing that over unless I have no choice.

It really seems like the stem is slipping on the steer tube, the fork and frame are new, as were both stems. Both stems I have used so far have been light XC stems with little 3mm bolts. I thought that maybe with the longer travel fork and slackish head angle might be putting extra stress on things. That’s why I ordered the Hussefelt stem, more suited for the setup and higher torque rating so hopefully better grip.

If that doesn’t work it’s going into the bike shop because I have no idea what to do. I’ve been trained on bike mechanics and have been riding 16 years and never been stumped like this.

14

You say this same headset has been on several different bikes, how old is it?

Have you done any web searching on ChrisKing headsets coming loose? The older ones are famous for this with longer travel forks/ agressive riding. I bet if you look closely at the fork there will be a bit of a groove starting to wear into the steerer tube where the bearing cap rubs on it.

They redesigned the top bearing cap a few years ago to fix this problem. They are avaiable from King here: chrisking.com/parts/bearingcaps

15

[quote=“Slider”]You say this same headset has been on several different bikes, how old is it?

Have you done any web searching on ChrisKing headsets coming loose? The older ones are famous for this with longer travel forks/ agressive riding. I bet if you look closely at the fork there will be a bit of a groove starting to wear into the steerer tube where the bearing cap rubs on it.

They redesigned the top bearing cap a few years ago to fix this problem. They are avaiable from King here: chrisking.com/parts/bearingcaps[/quote]

My new stem did not fix it, so it’s now at Bikes Plus getting looked at. And yes the headset is old, 13 years to be exact and has been installed on a 2000 Trek 8000, 2001 Norco Charger, 2004 Kona Caldera and now this bike.

Thanks for the link, I didn’t know about that headset issue and that would explain why it didn’t come loose on the old bikes with the short travel forks and now does with the longer travel fork. Mine is definitely not the new grip nut design. I’ll wait to see what the shop says and will probably take this route next.

Thanks again.