Originally Posted by
BobG
The specific construction of the Blackburn cage that I pictured at posts 6 and 14 allows for multiple ties down the center of the mounting bracket, not just one on each end, without interfering with the bottle. My fork blades are fairly large diameter at the top, also one zip tie loops around the top of a cantilever boss preventing slide down. Not sure if your carbon fork is beefy enough for a cage to be zip tied securely to it. Also looks like the center section of the Zefal "Spring" is raised out of contact with the tube so you can't use ties there. Those Blackburn cages are just $4-$5 and weigh 54g.
I'll try again with some metal cages I have laying around that do not have the bump in the middle like the Zefal does. Also try the inner-tube or similar wrap method. For my specific use case is for a short CCT I have coming up, I'll have a relatively light load and some spare room on the top of my rear rack for extra water but spreading some load to the front even if only 4lbs would be a nice option.
EDIT: I see the difference now.. The Zefal is flat on the back, works fine mounted up to a typical flat boss but inherently unstable and a tendency to roll when mounted directly to a curved surface (like my bossless fork). A Giant brand metal one I had laying around is concave and is way more stable.