Safety was seriously compromised when bikes were used beyond their capability and they were prone to rolling and tipping in a range of circumstances, he found.
There was a "Mexican stand-off'' between competing factions over the need for roll-over or crush protection devices, with manufacturers arguing they made bikes unstable, but academics and engineers saying they improved safety.
In all five deaths, the use of an after-market spray unit or trailer attached to the bike was a factor. Two of the farmers had also been using cannabis, which could not be ruled out as a factor, Coroner Shortland found.
His recommendations included:
* supporting a taskforce to perform research into roll-over protection devices, that may help protect the driver if a quad bike rolls.
* dropping of the term ``all-terrain vehicle'' and using quad bikes to refer to the vehicle
* endorsing the message from industry leaders that helmets should be mandatory
* ongoing research into training and education around quad bike use, including how to make training as accessible as possible
Farmers were also advised to consider carrying a personal alarm, as many of the victims were trapped under their bikes for some time before succumbing to their injuries.
