Head up the Kahakapao Loop
and find the entry to the trail on top of the mountain. The signs are very clear so it is impossible to miss.
Tune your suspension and bomb down this non-stop downhill. You'll go from a mixed forest to a pine forest, all Hawaiian style! The vibe is awesome, and the trail has clearly been built by professionals.
There are dozens of jumps and big bank turns everywhere. There is even a big wooden banked turn with a few big drops along the way. I would not recommend riding this trail when wet. Aloha!