The rise meant he did not see a left-hand bend until he was at the top. There was no warning sign.
He leaned to the left in a bid to navigate the corner but his bike slipped on to its side and slid across the road into the opposite lane.
At that moment a Nissan was rounding the corner from the other direction.
Petrie died at the scene from head and neck injuries suffered in the collision.
The rider's companions, St John medics and firefighters performed extensive CPR but could not save him.
Coroner Ho said he agreed with the Northland police Serious Crash Unit who found poor visibility and a lack of warning signs meant Petrie had to over-lean his bike to try to get around the corner.
He was riding under the speed limit but did not have time to react and adjust his speed to successfully negotiate the corner.
Another factor was the corrugations and ruts in the wheel tracks of the northbound lane just before the corner.
That was likely to have affected the handling of the bike, especially if leaning over at an extreme angle.
The Coroner said there were no mechanical issues with the motorcycle or the Nissan, and no one involved was speeding or under the influence of alcohol or drugs.
"This accident was not Ben's fault."
Waka Kotahi
national system design manager Robyn Elston told the Coroner chevron boards had since been installed in each direction at the crash site, and the speed advisory at the corner had been dropped from 55km/h to 45km/h.
Potholes and the road surface in the area had been repaired and in 2020 curve warning signs were reviewed along the length of SH1 in the North Island.
Elston told the Advocate that Waka Kotahi also planned to review the design of the curve where the crash occurred to learn if more safety interventions were needed.
''Waka Kotahi extends our thoughts to the whānau and friends of Ben Petrie ... Any death or serious injury on our roads has a traumatic effect on whānau, friends and communities, which is why we're focused on ensuring everyone can get where they are going safely and efficiently,'' she said.
During his inquiry Coroner Ho learned of three motorcycle crashes between 2013 and 2017 within 250m of the crash site. Two occurred on the same curve and involved a loss of control.
He was told there had been more crashes at that location which had not been reported, so the actual number could be higher.
However, given Waka Kotahi's response, Coroner Ho did not believe it was necessary to make any formal recommendations.
At the time Pukenui firefighter Guy Herring told the Advocate it was the fourth motorcycle crash on the "nasty, deceptive" corner in as many months.
The bend, outside the Department of Conservation base at Te Paki Station, also caught riders out because it appeared at first to be long and sweeping but tightened up halfway around.
Herring called for warning signs including a recommended speed for rounding the corner safely.
