good question. Subsrcibing for the answer 
No, weight would not be "easily" reduced. I have a titanium medium spring for my marzocchi 888, I have a steel medium and light spring. The titanium spring weighs about the same as the light spring. It does not save much weight at all. On a rear shock you are maybe saving 1/3rd a pound or so at the most. In some isolated cases where the spring is super long (like a 3 or 3.5" stroke rear shock) you might see some bigger savings, but I highly doubt you'd see much weight saved in a fox fork. You might save 100g, and the cost to benefit ratio is pretty poor. Titanium springs like that usually cost upwards of $100, more like $200.nitropiro said:Why doesn't anybody make titanium springs for fox 36VAN forks?
As an aftermarket part the weight could easily be reduced by using something like that