Originally Posted by TandemGeek

The Wound-Up carbon fork steerers use an aluminum insert to reinforce the stem clamping area and to support the use of a standard star-nut, which is similar to the True Temper Alpha Q. However, the fork legs are filament wound, compression molded carbon as is the steerer.

On the standard rim brake Wound-Up forks a CNC aluminum crown and drop-outs are CNC'd 7075 bonded to the carbon fork legs and steerer. On the Duo, a filament wound, all-carbon crown replaces the CNC'd 7075 piece and a CNC'd 7075 disc caliper mount is added to the lower left fork leg.