Originally Posted by
AnthonyG
If it was just the expanding plug then it wouldn't have a hex bolt head in it.
I'm not 100% sure. I'd need to check it out in person to know for sure, unless someone else really knows for sure.
I have one that's pretty much identical. Turning the hex head bolt is how you expand the plug and lodge it in to the top of the steerer. Inside of that hex head, there's threading for the top cap bolt, so as to adjust preload.
