Got my Cane Creek 40 external cup headset installed, got the fork through and trying to test out some stem lengths/rises before I buy the final one. So currently working with a taller steerer and a chimney of spacers. I’ve got the stem where I want to try it but I can’t seem to get the headset to tighten properly.

when leaving a some spacer above the top of the steerer tube so it doesn’t bottom out, I can’t get it to tighten just right. When I snug the top cap bolt to a reasonable tension, it snugs everything noticeably too tight. The fork won’t spin freely and loosely. The only way to get it to a spin freely leaves the top cap way too loose (like I can spin it with my fingers.)





what am I doing wrong?

Are you sure you have the headset/bearings installed correctly, with the bearings the right side up? I am not trying to me a wise ass, but are you doing the top cap bolt before the tightening the stem bolts?

Can't see what's under your stem between the headset and the stem. Are you certain your type headset doesnt' require something between them?

Not sure it has anything to do with your issue, but I've got that headset on a few of my bikes, and I always run a very thin spacer ( 1 or 2mm) between the top of it and the stem. I also really dislike that kind of top cap; maybe try one that's flatter on the bottom?

Delbiker1 already asked the question, but I'll repeat it differently: Are you tightening the stem bolts first or the cap?

I've seen bearings installed upside down, the compression ring installed in all sorts of (incorrect) places, the already mentioned not loosening the stem bolts before trying to adjust. It's unbelievable to me how many seemingly intelligent people can absolutely **** up something so simple.

I’m 90% sure the bearings are the right orientation but I will double check.

I was not tightening the stem bolts before tightening the top cap. I thought you left it loose so that the top cap could compress the entire column down snugly, then you tightened the pinch bolts. Am I wrong?

And yes I put a 2.5mm spacer between the top of the headset and the bottom of the stem. I started out with a 5mm spacer, swapped it for the smaller one - but has the same issue.

You are right about the tightening sequence, top cap just until it is snug, then stem bolts. If the bearings and compression ring are installed correctly, I do not know what your issue is. I still suspect it is one of those. To ensure correct assembly, have you dis-assembled the headset and looked at the instructions on the assembly? It sounds to me like it is the compression ring. I have had this happen. It is quite easy to error on the placement and positioning.

These are the instructions for the Cane Creek 40 EC headset: 40 EC & ZS Instructions (canecreek.com).

I have no idea what step #2 shows. As for step #3, I echo the above advice to make sure each piece shown is in the correct (i.e., not upside down) orientation.

So I double checked and everything is in the right way as far as I can tell. The beveled edges of the bearing rings both face into their respective cups. The top assembly is all one piece - I assume this includes the compression ring which that video mentions. Because there aren’t any more parts, and the exploded diagram in the manual doesn’t mention anything else.
see pics below:

You've probably checked, but I'll throw it out there anyway. Have you checked the star nut, that it hasn't slipped upward while tightening the top cap?

[1] When the whole stack is assembled, is the top cap shown in the second photo sitting (a) on top of or (b) within the inner circumference of the top spacer shown in the first photo?

[2] Do you experience the same problem if you move at least one spacer to between the stem and top cover assembly? I think you should try this. Your problem sounds like at least two components within the whole stack are not sitting flush against each other.

no I think it’s in there pretty solid.

the top cap sits on top of the top spacer.
i did have a 5mm spacer between the stem and the top of the headset. Also tried it with a 2.5mm.

Are the cups pressed in on the level with the head tube? I sort of remember having a similar issue with a CC 40 the first time I installed one. Not saying you did this, but, I mistakenly installed the cups top on bottom, bottom on top. and one was not level in the tube. Once corrected, all was good. I have installed a couple since with no issues.

the sci guy Any updates? Hope you have solved this problem. My headset arrives tomorrow.

Turn the top cap upside down and see if you still have trouble setting the headset bearing preload or use taller spacers. I'm betting you're getting interference.

What does interference mean in this context? Sorry if I am asking a super noob question, but I have never replaced a headset before.

The top cap is there to provide headset bearing preload. It can't do that if the top cap makes contact with the top of the steerer tube or star nut. Read "makes contact" to also include "interference".

Not yet. I decided to wait until my actual stem arrives, which hopefully will be tomorrow so I can tackle the problem over the weekend. Though I will be cutting the steerer tube down once I dial in a height, so hopefully I won't run into the issue again after I hack it off.

It looks like the top cap could bottom out if you trim the steertube. I would live with the stack as is.