The popular motorcycle event allows riders to use about 100km of marked trails through Deep Creek, Long Gully and Lindis Stations, near Tarras.
It is the fourth year for the annual event, which has raised $80,000 for the Wanaka Primary School and Montessori Children's House.
Last year, more than 700 riders took part and more are expected this year.
Spokeswoman Alice Lovelock told the Otago Daily Times the limit was put in place for safety reasons and to ensure there was no overcrowding.
"It was important for us to limit it so riders were able to have a good experience.
"If the tracks are too full, people won't appreciate it and won't come back."
She said the event had grown as a result of "word of mouth" and its popularity was partly due to riders not having to arrange permission to enter properties.
The event is designed to cater for riders of all abilities and is managed by a volunteer workforce of 125 people.
Volunteer manager Gillian White said more than 1000 volunteer hours were being contributed by students, parents, grandparents, teachers, trail ride enthusiasts and local professionals.
Children from the school and house had been busy hand-drawing thank you cards for volunteers and sponsors, something that had become "a popular and well received tradition" since the event started, Ms White said.
Trails Manager Grant Cagney said while the family and intermediate trails would remain the same as in previous years, trails for developing and advanced riders would be enhanced.
"We aim to have trails for the developing riders' first excursion into single-trail riding, as well as challenging expert loops.
"New single-track hill climbs and descents have been marked-out through steep tussock country on the front faces. which allows experienced riders to get off the main drag," he said.
