I'm not too big a fan of compression plugs, or at least the profile one I've used. It wouldn't preload my headset tight enough and after a few rides it would loosen up, which obviously isn't any fun to ride around with a rattly loose headset.

I just stumbled across these head lock / stem lock things, which from what I can tell get great reviews... on mtbs. I didn't find anything on somebody using one for a road bike, and I'm not sure if they're intended to be used with a carbon fork at all. Has anyone used one on their carbon steerer fork? Or can anyone recommend a compression/expansion plug that stays put and allows ample clamping force without needing to be adjusted every few days?

https://www.jensonusa.com/!moywUmxbN9...c-Head-Lock-II

Let's trouble shoot before you go spend some money.

Clamping the stem holds the adjustment, so something there is going wrong. The plug and top cap pull the fork up and push stem/spacer stack down to load the headset. If the top cap is coming in contact with the steer tube then it won't work.

You might just need a taller spacer above the stem (assuming you already have one there)

What he said.

Something else is amiss. Maybe a missing compression ring. On my cane creek there was a washer gasket thing that made adjustment impossible. What kind of headset?

That too. I know people that have tossed their compression ring because they "didn't realize" that was a piece of the headset.

Also the compression plug is not what holds the headset tight. All it does is pull it together for the stem to clamp down and hold it. Make sure your stem is tight enough (but not too tight.)

•There was a good 3mm of space between the top spacer and the top of the fork, plenty of room. With the plug tightened all the way down the top spacer could still twist if I gave it a little force which tells me it wasn't being compressed enough.
•The stem seemed to be tightened enough based on the fact there are slight indent lines at the top and bottom of the carbon steer tube where the stem was. I don't have a torque wrench though, never used one.
•The headset is whichever FSA zero stack fits the Leader 725 frame, no parts are missing.
•The plug was a crappy Profile Designs one that is plastic, I did not use carbon paste, was not informed such a product existed by the lbs where I purchased the plug


From what I've read people in general have issues with compression plugs and their sh*t coming loose every so often so that it does require maintenance. I have no problem maintaining my bike, but to constantly have rattling in the headset area when riding no handed anytime I went over rough pavement or a bump just isn't the kind of reliability I want.

I have a brand new 3t Funda Pro fork, uncut steerer, never installed and a brand new FSA Vision tech stem. I'm not going to use that crap profile plug again. So I'm sending money no matter what. I just want to spend that money on something that will work the best.

Wtf dude, your plug is coming loose. Get a different one. Anything. Whatever.

You said
Now you're saying the headset is fine it's just the plug that's rattling?

I have pretty good reading comprehension and I cannot figure out what your issue is.

If your headset is properly adjusted, it does not "come loose" bc of the plug. If it comes loose it was not installed/adjusted properly - unless the problem is being caused by something other than the plug.

Unless you are saying that the crapppy plug is preventing you from installing correctly. In which case it's not loosening after a few rides, it was loose to begin with.

Move this to the mechanic forum.

Those Profile comp plugs suck. Get an FSA plug or similar.



And this.

I'm going to guess that 3mm isn't "plenty of room". get a bigger spacer up top and see what that does for you. there can be a lot of slack to take up in a sealed cartridge headset that you can't necessarily feel. The headset doesn't wobble if you hold the front brake and rock the bike, but the fork will slide up and down in the headset. It's still loose, and will sound loose while riding but it's a different kind of loose to diagnose than a caged or loose ball headset.

I am rather confused myself. The top cap and the star nut or whatever preload device you are using has one duty, to preload the steerer so that you can then clamp down the stem. The stem itself is what keeps the preload in check. After you preload the steerer with the top cap, you then tighten down the stem firmly as you can for the type of steerer you have, you should then be able to completely remove the preload cap and still ride the bike without it loosening up since it is the stem that keeps the preload proper, not the cap any longer.

If it is loosening up, I might look at the issue in a different way. I imagine that maybe the stem is sliding up the steerer during bumps. Use some sort of gritty carbon paste on the stem/steerer to prevent it from sliding?

that's why many use a 5mm spacer

I'd say 1.5mm is plenty of room. How much do you expect carbon and steel to compress?

Given the function of a compression plug, is substituting where a Star nut
would really mess up a carbon steerer-carbon fork..

got the steerer tube length dialed in?

you can use a plug of aluminum (Zn free, no 7000 series)
Machined.. and the center threaded for the 6x1 bolt .
and OD sized to just slip into your steerer tube ..
and epoxy it in place.. 5mm below the top end.

Perhaps I miss spoke. Maybe it's just the spacers on the stem that are loose. More or less the same thing though, the sh*t that the steerer tube runs through is making noise because it isn't all tightened down enough because of crappy plug and/or as somebody below said the stem is sliding up after a few rides. Not very difficult to understand.

Hadn't thought off using paste between the stem and steerer, helpful and thanks

I do use a 5mm spacer on top, but my steerer sticks up about 2mm higher than my stem, so there is 3mm left when everything is pushed down real well just before tightening in the plug.

That seems like a lot of money to go have machined and a lot of work when the original question in this thread was if a headlock works on road carbon forks and is a simple $25. Is there any issue using that system in this application?
The only one I can think of is that I've heard a dual function of a compression plug is to counteract the squeezing forces of a stem with it's own pushing forces in the same place on the steerer. Plug is pushing out, stem is clamping down, if equalish amounts pressure is neutral on steerer. True or rubish?

Probably rubbish,, cheap fix wrap the expander with double stick tape.

if your spacers are looser the stem bolts are not tight enough,
Torque wrench puts a number on how tight.. get one.
Carbon stuff prints numbers on it now
The top cap just pulls down on the whole stack once the stem is loosened,
once you tighten the stem bolts, the top cap and Etc, it's just along for the ride.

my Dad [RIP] was a machinist so I think about fabricating stuff, still ..

What happens when you get the preload, tighten the stem, remove the compression plug and then ride? Just trying to understand the issue clearly.

I can't get enough preload and it sounds like my stem was slipping while riding. I have yet to install the new fork and new stem, I'm going to get a better compression plug first, which was part of the point of this thread. I'll also get some carbon paste to help hold the stem in place better.

I'm having trouble believing that a stem would let the steerer slip through without falling out of alignment with the tire.

Go to a shop, man- you're missing something here, and it sounds like it could be dangerous.

Why not just try putting a bit of tape around the expander plug you already have?

I can see it; there's no rotational force strong enough acting on the joint to cause it to slip, but the much stronger and purely vertical/fore-aft pounding through the headset is enough to make the stem creep up over time.