There is close to 20km of trails in the Rangituhi Trails network. They cater to all abilities although there are no extreme trails. You'll find good climbing singletrack in addition to the four wheel drive access road that is a granny gear climb all the way to the top of the hill.
Most of the trails are down sloping cross-country style. They are all very well designed, true to their grade and packed full of technical features such as humps, jumps, berms, drops, switchbacks and so on. Mostly you're in pine forest, sometimes in open pasture and sometimes in native forest. If you're looking for air there is plenty of that too but in small doses - you won't find big tabletops or similar.
The trails are the work of the Mana Cycle Group and development of the network is ongoing. The group has a website at: http://www.manacyclegroup.org.nz/ and a facebook presence as well.
Here is the club's suggested loop around the trails: "Ride Spicer Link to The Doctor which will climb you part way up the hill. From there make your way up Farm Road to Chimney Sweep which you can bomb down and enjoy the views. Currently there is nothing linking Chimney to Tumeke but a grassy 4x4 road with a few features on the side. Short pedal up the hill takes you to Upper Tumeke which will be the trail of the day for everyone. At the bottom you pop out very close to the car park where you can enjoy another lap or call it a day."
The network is visitor friendly with good signage so you won't get lost. Whatever you do don't miss Upper Tumeke - it's a masterpiece of singletrack artistry.