Thompsons Track is a very rough old unformed four wheel drive track that crosses the Kaimai Range between Katikati on the east and Matamata on the west. It's much loved by the four wheel drive clubs who enjoy getting bogged in the winding thread of monster holes and ruts that is the "track"! For mountain bikers it is the only legal crossing of the Kaimai Range.
On either side of the range the track starts out as a maintained road but it soon leaves civilisation behind as it enters the forest and climbs towards the crest of the range some 400 vertical meters above. Don't bother with it after rain. In fact, only attempt it after a long hot dry summer! When wet the track is a messy mud purgatory - or heaven if you're a petrol head!
You can ride it out-and-back from either side - if you really want to! Or just go up to the top, take in the views and head back the way you came. Best of all would be to organise a shuttle - there is no legal biking track back over the Kaimais to make a loop of it. It's about 20km from one side to the other.
As you take in the view from the summit, bear in mind that you are not far from the site of New Zealand's worst internal air disaster. Twenty three people lost their lives in 1963 when a DC3 crashed one stormy evening as it crossed the Kaimai Range on its approach to Tauranga airport.