I haven't had much success with syncing and use a stick to bring Bookmarks over. I have not found a way yet to cause the HTML file to create a new Bookmarks toolbar from scratch - in this case a new OS.
For ease of transfer I drag the newly introduced bookmarks folder up onto the new Toolbar and then drag each one left or right - finally deleting the introduced Bookmarks folder from the Toolbar.
It's obviously better to sync when everything is settled, but in this era of W7 - W10 upsets, I've done a lot of fresh installs.