Is the height maxed out into the bottom of the sleeve or is the base of the spring just touching the top of the sleeve?
I'm not too sure, but I think if you tighten up the preload (stiffening and compressing the spring), you might have some more thread you can stuff into the sleeve.
Of course it would also increase the spring rate a little at the same time...
i have no personal experience with actually doing that though, just a thought...
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