Motorcyclists are pulling out of Pukekohe Raceway after failing to resolve safety concerns about changes made to the track for the V8 races next month.
The move ends half a century of motorcycling at Pukekohe, 50km south of Auckland.
Auckland Motorcycle Club president Graham Bastow said a training day on April 21, the weekend after the V8s, was being moved to Hampton Downs.
The motorcyclists were concerned a $6.6 million upgrade for the V8s included concrete barriers next to the track on a turn known as the Mountain Bend.
They say the barriers, which are removable, leave no run-off area in case motorcyclists fall, or space for soft barriers used to break their fall.
Motorcycling New Zealand president Jim Tuckerman said he hoped a solution could be found to eventually get motorcyclists back to Pukekohe.
Meanwhile, Mercedes and Nissan fans are expected to also be well represented in the crowds at the V8 Supercars event.
V8s spokesman Cole Hitchcock said Ford and Holden supporters had dominated trackside for 20 years, but that was beginning to change.
"It's not just a Holden and Ford event any more, and Nissan and Mercedes have opened it up to an an additional audience."
Organisers were expecting a crowd of more than 130,000 over the three-day event.