The Department of Labour has rejected a coroner's call that roll bars and lap belts on all quad bikes could help save lives.
The department says lap belts would make it extremely difficult to ``actively ride'' a quad bike and the science of roll bar protection is incomplete.
Filipino beekeeper Jody Dean Santos, 21, of Masterton, died from a massive skull fracture days after he was ``catapulted'' off a quad bike he was riding at work in August 2008.
In his findings on the death, Wellington Coroner Ian Smith said accidents involving quad bikes had concerned coroners for a long time -- about 120 had been killed on them in the past 10 years.
Mr Smith said he was frustrated by the failure of authorities to take up the recommendations coroners ``consistently'' made.
He recommended the Labour and Transport ministers undertake an immediate investigation to consider the mandatory use of helmets, roll bars and lap belts on all quad bikes.
But Department of Labour national support manager Mike Munnelly said that while it supported compulsory helmet wearing, to ride a quad bike safely it was absolutely necessary to be able to stand up and to shift body weight for balance -- or ``active riding''.
``A lap belt or restraining system makes it extremely difficult for a rider to make these safety corrections and exposes them to increased danger,'' Mr Munnelly said.
``The science supporting roll-over protection bars being fitted to quad bikes is far from complete. If the science does prove the value of these bars then the department will support their introduction.''
The department launched a quad bike safety campaign in November which pushed the message that riders must be trained and experienced enough to do the job, children should not ride adult quad bikes, always wear a helmet and choose the right vehicle for the job.