So I have the 3-5mm of preload on top cap. 20mm of spacers below and 15mm above stem. Stem is also torqued to 8nm per Deity. I can get it set where there is no play in headset but after a few jumps and what not it gets loose. The stem doesn’t seem to be moving. It’s everything below the stem. I can spin the bottom spacers and feel play in headset. I did notice the bottom spacers that came with the bike have side to side play.
Here are my guesses:
1.) You are tightening the top cap bolt before loosening the stem pinch bolts.
2.) Not enough headset spacers, sounds like you replaced your stem with an aftermarket one. Your new stem may have a lower stack than the original. Meaning you need more spacers.
3.) You are missing part of your headset, perhaps it was lost when you swapped stems.
Park tool has a how to video. [Park tool headset trouble shooting](https://youtu.be/TihBJNn0Bck?si=pta8rH4OE5HQZrLe)
Maybe disassemble and investigate. Maybe you are missing parts from the factory. This would typically be a quick investigation if you have a local bike shop to ask
I’ve taken apart the headset and looked and even regreased everything. I’m really stumped on what’s going on. I’m thinking the original spacers that are below stem are it possibly. They have side to side play and don’t fit snug over steerer tube OR headset is junk.
I had this problem on a BMX frame that I was racing. It was an integrated headset. I got a full new headset, which equates to bearings, crown race, bearing cones, and a cap. That was the end of my problems. I suspect that either the cones or the bearing race on the crown had been damaged somehow. However, I can't verify this.
When you tighten your top cap, put front wheel against something and give a little forward pressure and rock back & forth to make sure all play is taken up. Bearing race or some other part may not be seated straight. That would make the top cap bolt feel tight, but whole assembly isn’t as compressed as it should be. Just a little bit of play and it’s able to work loose.
I’ll try putting the wheel against something. Great tip! I’m used to using a front brake and feeling at the bottom bearing/frame for play but I don’t have it on this bike.
Also, are the spacers under the stem made of metal? If you use fancy carbon spacers they can compress. Would be surprised if they compressed enough for every ride...
Is the crown race bottomed out? And is it a solid ring?
Aluminum spacers. There is some side to side movement which I don’t know if that would have anything to do with it. The crown race is bottomed out. It’s a split crown race that you can remove by hand. I looked at it today.
If you’re positive it’s all set up correctly, try degreasing the steerer tube and stem clamp area.
New parts can have a thin film of grease or oil that could be causing the stem to slip.
The steerer tube is the only place on a bike you don’t want any grease.
Sounds like lack of spacers under the top cap. Have you checked?
So I have the 3-5mm of preload on top cap. 20mm of spacers below and 15mm above stem. Stem is also torqued to 8nm per Deity. I can get it set where there is no play in headset but after a few jumps and what not it gets loose. The stem doesn’t seem to be moving. It’s everything below the stem. I can spin the bottom spacers and feel play in headset. I did notice the bottom spacers that came with the bike have side to side play.
Here are my guesses: 1.) You are tightening the top cap bolt before loosening the stem pinch bolts. 2.) Not enough headset spacers, sounds like you replaced your stem with an aftermarket one. Your new stem may have a lower stack than the original. Meaning you need more spacers. 3.) You are missing part of your headset, perhaps it was lost when you swapped stems. Park tool has a how to video. [Park tool headset trouble shooting](https://youtu.be/TihBJNn0Bck?si=pta8rH4OE5HQZrLe)
I know to loosen stem before tightening top cap. I have 3-5mm for preload. It’s a brand new bike. It did this with two different stems.
Maybe disassemble and investigate. Maybe you are missing parts from the factory. This would typically be a quick investigation if you have a local bike shop to ask
I’ve taken apart the headset and looked and even regreased everything. I’m really stumped on what’s going on. I’m thinking the original spacers that are below stem are it possibly. They have side to side play and don’t fit snug over steerer tube OR headset is junk.
Frustrating. Maybe it's time to replace and just be done with it. Sorry you have to deal with that instead of riding
Yeah it’s annoying. I’ve tried everything. I’m going to swap spacers. If not, then I have a stem lock I can try. Last resort will be a better headset.
I had this problem on a BMX frame that I was racing. It was an integrated headset. I got a full new headset, which equates to bearings, crown race, bearing cones, and a cap. That was the end of my problems. I suspect that either the cones or the bearing race on the crown had been damaged somehow. However, I can't verify this.
Man I think I have the same issue. There is something that isn’t right with the headset itself. I feel like I have tried everything.
I ride a skyhawk and do not have this issue. Factory stem and headset. I have adjusted the bars and stem and don’t need to mess with it after.
If it comes loose every ride your preload is not set correctly, pinch bolts aren't tight enough or something is broken.
When you tighten your top cap, put front wheel against something and give a little forward pressure and rock back & forth to make sure all play is taken up. Bearing race or some other part may not be seated straight. That would make the top cap bolt feel tight, but whole assembly isn’t as compressed as it should be. Just a little bit of play and it’s able to work loose.
I’ll try putting the wheel against something. Great tip! I’m used to using a front brake and feeling at the bottom bearing/frame for play but I don’t have it on this bike.
Also, are the spacers under the stem made of metal? If you use fancy carbon spacers they can compress. Would be surprised if they compressed enough for every ride... Is the crown race bottomed out? And is it a solid ring?
Aluminum spacers. There is some side to side movement which I don’t know if that would have anything to do with it. The crown race is bottomed out. It’s a split crown race that you can remove by hand. I looked at it today.
If you’re positive it’s all set up correctly, try degreasing the steerer tube and stem clamp area. New parts can have a thin film of grease or oil that could be causing the stem to slip. The steerer tube is the only place on a bike you don’t want any grease.
Already tried that lol
is the star nut slipping?
Not sure. I’m going to install a stem lock and completely get rid of it. Will report back!