This is a question for @Jonathan or others who have used this product. I recently ordered one of these top caps to get my gravel build a bit lower at the front (Cervelo Aspero). However, when I install the top headset bearing and what I refer to as the “compression ring” (the blue collar that seats/centers the steerer tube in the top bearing), there is a substantial visible gap between the STS dust cover/top cap and the head tube. In fact, you can see the side of the top bearing, and the top cap doesn’t come close to sitting near flush to the head tube as a normal top cap would. For whatever it’s worth, I am using a Cane Creek Hellbender bearing set, and when I install the headset, the bearing sits a little proud of the headtube. This isn’t a problem with the normal headest cap provided by Cane Creek, as it all fits together nicely.
For a good image, the picture of the STS top cap installed on the bike in this Weight Weenies thread after all of the pictures of the food scale weights is similar to what I’m experiencing:
Pics? Which Hellbender? Hellbender 70 IS41? Bearing and Headset or just the bearing with the SlamthatHS top cap?
The Hellbender top cap doesn’t have enough “Skirt” area?
First thing I’d check is to make sure the fork and bearing are fully seated, then the compression ring is fully seated, and then you push down on the whole setup while you tighten the steerer cap. If everything isn’t taught, you might have a gap there, there should be no play in the fork steerer with the top can tightened down.
If you put any shims between the top cap and the compression ring, you can pull those out.