Fox built the RAD (Racing Applications Development)

with an experimental "one-piece" titanium tapered steerer and crown.

Race mechanic Mike Van Lienden says the setup is not only more rigid than an equivalent aluminium piece but also lighter

– despite titanium's higher density –

owing to the thinner tube walls and more efficient one-piece construction. 

Fox built the RAD (Racing Applications Development) crown with cast construction rather than forged as the hollow interior could be built right into the mould rather than having to be machined later. 

Why not just go with carbon? According to van Lienden, the company simply have more experience with titanium and also wasn't entirely confident in the long-term reliability of bonded joints. For now, it's a race-only item as Fox complete testing, but you can probably expect to see it in the shops in spring 2011.

Ref.)

Interbike 2010: Fox Racing Shox RAD Float Ti fork