Crankenstein is a Black Diamond-difficulty downhill track descending off the western side of Sunrise Ridge and into Maitai Valley. The trail runs through native bush and features lots of rocks and roots. It can be used as an alternative to the upper section of 629, which removes the climb at the northern end of Sunrise Ridge. Crankenstein ends midway down the valley slope and can be combined with the lower section of 629 to make a full descent to the valley floor.
Crankenstein begins on Sunrise Ridge next to beginning of Peaking Ridge track. As Crankenstein starts halfway along the ridge, it is a little bit out of the way. Bob Taylor Road provides the most direct access if you are going specifically do to this trail. Bob Taylor Road begins off Dun Mountain Walkway, beyond the Maitai Valley road end. Follow Maitai Valley Road to the road end, and continue across the pedestrian bridge to Dun Mountain Walkway on the true left of the Maitai River. Follow the walkway for 1.3 km and turn right onto Bob Taylor Road. The road climbs through pine forestry for 3.2 km before reaching the road end at the northern end of Sunrise Ridge (at 629 m elevation, hence the trail name). Sunrise Ridge Track and 629 start right next to each other (both are signposted).
Otherwise Crankenstein can be used as an alternative to Peaking Ridge for those coming via Fringed Hill and Black Diamond Ridge.
Crankenstein descends the western slopes of Sunrise Ridge, and follows a narrow spur, weaving in between beech trees. The track is loose and rocky in places and there are some off-camber rooty sections to cope with. There are plenty of tree trunks and head-level branches overhanging the track to dodge, as well as a couple of steep chutes to navigate.
Crankenstein finishes up on Big Hill Track (a forestry road); from here it is a short ride north along the road to reach the beginning of the lower section of 629.