"I just think it's a no-brainer.''
Nationally, police have issued more than 85,000 tickets to cyclists not wearing helmets in the past decade.
Fourteen cyclists have died on New Zealand roads and 332 have suffered serious injuries since January last year, New Zealand Transport Agency figures show.
Two of the dead cyclists were not wearing helmets.
Non-compliance can result in a $55 infringement fee or maximum $1000 fine on summary conviction.
Cycling Advocates Network (CAN) spokesman Patrick Morgan said the organisation wanted the helmet law reviewed as it deterred potential cyclists.
However, cycle lanes and vehicle speed reduction were more important priorities, he said.
Mr Morgan obtained an exemption to the helmet legislation under medical grounds armed with a doctor's certificate in 2004.
He wears a helmet only when he deems there is sufficient risk.
"It's kind of like if you imagine a car racing driver. They'd probably wear a helmet because they're doing a high-risk thing, but when you drive down to KFC you probably wouldn't bother.''
NZTA spokesman Andy Knackstedt said exemptions could be given on religious or medical grounds. Nearly 150 exemptions have been granted since the law was introduced _ four this year.
Bicycle helmets were made mandatory in January 1994.
The origins of the law were widely attributed to the campaigning of Rebecca Oaten, dubbed the "helmet lady'', in the late 1980s.
Ms Oaten campaigned for helmets to be made compulsory after her son Aaron suffered per manent brain damage when he was hit by a car while riding his 10-speed bicycle to school in Palmerston North in 1986.
Ms Oaten said a doctor told her Aaron would "almost certainly not have suffered brain damage'' if he was wearing a helmet.
Aaron died in 2010 aged 37.
A New Zealand Medical Journal article published in February this year found that New Zealand's bicycle helmet law had failed in aspects of promoting cycling, safety, health, accident compensation, environmental issues and civil liberties.
The article estimated the law cost 53 lives each year in premature deaths because of a corresponding reluctance to cycle and lack of exercise. A 2011 Ministry of Transport survey found 93 per cent of cyclists wore helmets.
Tickets Issued
Past 10 years (nationally): 87,738.
1128 tickets issued in Rotorua between 2002-2011 _ 54 waived.
116 tickets issued in Rotorua in 2011 _ 7 waived.