The Department of Conservation says the Heaphy Track will be opened to mountainbikers again this winter, but only during daylight hours to protect nocturnal giant snails.
After a successful trial last year it will be opened again to bikes from May 1 till September 30.
DOC said today that last winter some riders had underestimated the difficulty of the track and their journey times and did not make their intended stop for the night.
Riding is not permitted on the track during darkness to protect the giant powelliphanta snails and great spotted kiwi that may be crossing the track.
DOC Buller area manager Bob Dickson said mountainbikers should expect a tougher ride than on some other popular multi-day rides.