Kerry and I rode the northern end of The Old Ghost Road, which starts in Seddonvile. Parking at the Rough and Tumble Lodge, we rode up to Specimen Point Hut and then on to the Mokihinui Forks Hut before coming back. It's about 42km with 1200m of climbing for a full day out.
If you're looking for a good day trip on the Old Ghost Road, I like riding this end more. The Lyell end is heaps of climbing (pays off with a long descent coming back, though), but you're mostly in the trees and don't get the views.