How about a titanium core with a carbon lining as shafts?! This can work for both shafts right?! Titanium giving rigidity and carbon giving 'bend-resistance'?
Gary; you're right, i forgot about how to 'connect' the shafts. Carbon isn't suitable for screwing, but maybe just a core of titanium on the 'connecting' ends?

Or am i thinking way to complicated and just go with two different materials for inner and outer? (I think the stock outershaft is also press-fitted into the gear, just as one would need to do with carbon right?)