Mountain-Biking in the National Park is restricted to ROADS ONLY.
There are a few shingled roads that make good riding:
MT WHITE ROAD
The turnoff from SH 73 is 25km from Arthur's Pass towards Christchurch. This road climbs up hill and down dale following the Waimakariri River to Mt White Station.
POULTER RIVER to TRUST-POULTER HUT
Near the end of the Mt White Road is the Poulter valley. There is vehicle access up the Poulter river on a four-wheel drive track, as far as the National Park Boundary at Mt Brown Creek. Beyond this point mountain bikes are permitted to follow the "road" and walking track as far upstream as the 6 bunk Trust-Poulter Hut (25km) on the true-right of the Poulter River. Cyclists are NOT PERMITTED on the Andrews Valley track system, or above the Trust-Poulter hut.
KOROWAI / TORLESSE TUSSOCKLANDS PARK
Mountain biking is permitted on formed tracks in this conservation area. A popular track leads from either the base of Porters Pass, or Lake Lyndon to "Trig M".
The access up the Taipo starts just west of the Rocky Point Scenic Reserve ( Approximately 40 km drive west from Arthur's Pass). It is possible to Cycle up to Seven Mile Hut, about an hour riding.
It may be possible to approach local landowners to ask permission to cycle on private land - Stations such as Flock Hill Lodge have many 4 wheel drive roads that are suitable for mountain-biking.
CRAIGIEBURN FOREST PARK