July 2024 Update: Finally fixed 2022 Crux Headset Problem!

[Turkle]

I had something similar happen on a bike. After a lot of fuss, it turns out that the expander plug wouldn't sit tight in the steer tube, so when I tightened it down it would pull out a bit. So I never got proper preload. It caused the bike to shudder like mad under hard braking, genuinely terrifying.

I replaced the cheapo expander plug with one of those long Specialized plugs. That thing isn't going anywhere. Solved the issue for me.

Not sure if this is what you're experiencing but it sounded similar.

[proletariandan]

Originally Posted by yinzerniner

I had this issue with a bike that I built up, and it was due to the interface of the headset top cap, the fork steerer plug and the top of the stem.

Basically, for whatever reason the inside face of the headset top cap (chris king) when mounted flush on top of an Enve stem didn't really play nice with my specialized steerer plug. Even when torquing it down, it still exhibited a bit of play and went loose over the course of a mild ride. So I added a thin spacer between the headset top cap and the stem and that gives the cap a little room between it's shape and the shape of the stem. In other words, instead of the top cap sitting directly on top of the stem, the top cap is pushing against the spacer which is then pushing against the stem.

It probably won't solve your issue but might be worth a try since it's very easy to install/reverse.

Do you mean a super thin .1mm plastic spacer? I already have regular carbon + alloy spacers between the top cap/stem (6mm) and between the headset cover/stem (10mm).

Originally Posted by Turkle

I had something similar happen on a bike. After a lot of fuss, it turns out that the expander plug wouldn't sit tight in the steer tube, so when I tightened it down it would pull out a bit. So I never got proper preload. It caused the bike to shudder like mad under hard braking, genuinely terrifying.

I replaced the cheapo expander plug with one of those long Specialized plugs. That thing isn't going anywhere. Solved the issue for me.

Not sure if this is what you're experiencing but it sounded similar.

This is the Specialized plug and I'm pretty sure this isn't the issue because I do get proper pre-load, there is somehow still some play.

[John H.]

The crux of the issue (pun intended) is that the headset that comes on the Crux is garbage. It is like rubber and plastic, has a plastic compression ring.

Wolftooth is the only one I have found that makes a quality aftermarket headset that fits.
https://www.wolftoothcomponents.com/...rated-standard

You can also get the performance version- It has the same compression ring and topcap, just has a cheaper bearing.

and this lower bearing-
https://www.wolftoothcomponents.com/...rated-standard

I put both of these on and have not had an issue since. With the stock headset, it would come loose. Adjusting it always ended up a touch tight or a touch loose.

[catchourbreath]

I personally never found the specialized bearings to be much different than any others, besides being lower Stack and thus not interchangeable with stock off the shelf units.
My usual working pattern with a sorta uncertain origin would be to take more things apart, clean and lube accordingly. Sometimes something isn't installed right (top cap bottoming out on expander, bearing cover hitting frame) or just a combination of things. At least scratch all that off the list.
While doing that check for any damage!

[John H.]

It is not so much the bearings- It is that the compression ring is plastic and the topcap is junk.

Originally Posted by catchourbreath

I personally never found the specialized bearings to be much different than any others, besides being lower Stack and thus not interchangeable with stock off the shelf units.
My usual working pattern with a sorta uncertain origin would be to take more things apart, clean and lube accordingly. Sometimes something isn't installed right (top cap bottoming out on expander, bearing cover hitting frame) or just a combination of things. At least scratch all that off the list.
While doing that check for any damage!

[tctyres]

I had a similar problem with a Cannondale CAAD 12. I bought a Ritchey headset and the problem was solved. At least by eye, the bearings were the same, but something was different. I have no idea what, but the problem was solved. The original headset was an FSA, and I've never had a problem with them before.

My recommendation is to buy a Ritchey headset if they have one that fits your frameset.

[.RJ]

Originally Posted by catchourbreath

I personally never found the specialized bearings to be much different than any others, besides being lower Stack and thus not interchangeable with stock off the shelf units.
My usual working pattern with a sorta uncertain origin would be to take more things apart, clean and lube accordingly. Sometimes something isn't installed right (top cap bottoming out on expander, bearing cover hitting frame) or just a combination of things. At least scratch all that off the list.
While doing that check for any damage!

Most tarmac/crux/allez headsets use a proprietary lower bearing because the lower race is molded into the fork crown. Its a real pain because their headsets are absolute garbage, lasting a year or two at best before they first get play, then explode when you remove the fork to clean out and re-grease. My 2018 allez sprint is on its 2nd headset and my 2015 crux its 3rd.

[Stuff416]

I had a similar issue with my crux, somehow the compression plug/cap was affecting tightness. The solution for me was to tighten down the top cap to correct preload, then back off top cap screw a couple turns, then tighten stem, and finally tighten top cap back down.

[proletariandan]

Thanks, y’all! Are any of your issues with a 2022 Crux? Not sure if the earlier ones had the same headsets.

[John H.]

My issues and comments are specific to a 2022 Crux. I actually own and ride that bike.
Get the recommended Wolftooth top and Enduro bearing bottom and be done with it.

Originally Posted by proletariandan

Thanks, y’all! Are any of your issues with a 2022 Crux? Not sure if the earlier ones had the same headsets.

[kppolich]

Originally Posted by Stuff416

I had a similar issue with my crux, somehow the compression plug/cap was affecting tightness. The solution for me was to tighten down the top cap to correct preload, then back off top cap screw a couple turns, then tighten stem, and finally tighten top cap back down.

This is a high quality answer.

[catchourbreath]

Perhaps I'm misunderstanding but what's the point of tightening the preload cap, then backing off, THEN tightening the stem? You lost preload the second you backoff the cap with the stem loose. Also tightening cap after the stem is torqued isn't having an effect on the preload.
If anything just snug the cap, tighten the stem.

[eddief]

just asking.

[Pinned]

It doesn't look like there is anything proprietary about the Specialized bearings.

From what I can tell the upper is either IS41 or IS42 - you could figure it out readily with a set of calipers.

The lower looks to be an IS52/40 with a 45* interface. Chris King, Cane Creek, and plenty of others make headsets for this application.

I'd pull it all apart, inspect the frame, measure the bearings with calipers, and order a replacement headset of your choosing.

[.RJ]

Originally Posted by Pinned

The lower looks to be an IS52/40 with a 45* interface. Chris King, Cane Creek, and plenty of others make headsets for this application.

Unless they've recently changed how they do headsets, the lower bearing is proprietary - which is a real pain since they're both not cheap and not always immediately available. I've had a bunch of people including bike shop mechanics claim that other options exist but never actually seen anything turn up.