Motorcyclists were to blame for 70 per cent of all Auckland City crashes in which they were involved over the past five years.
Police statistics show two-wheelers were the leading "vehicle at fault" when involved in accidents every year from 2004 to last year - peaking at 74 per cent in 2006.
And of the last three fatal crashes involving motorcycles in the city, two were the result of a speeding rider, either unlicensed or on a learner licence, said Auckland city road policing manager Inspector Gavin Macdonald.
Automobile Association statistics show the problem is nationwide, with motorbikes and scooters causing 87 per cent of the 2303 fatal and serious injury crashes they were involved in between 2003 and last year.
Police and industry experts believed one cause of the crashes was the number of middle-aged men trying to recapture their youth by returning to the motorcycles they rode when they were young.
"I think they get a second zest of life and jump back on the bike and they are thinking they are back to being 25 ... But the bikes are more powerful, their co-ordination's not as good and there are more cars on the road," Mr Macdonald said.
AA general manager for motoring affairs Mike Noon had also noticed a surge in "returned" riders.
"And that's not saying that if you're an older rider, you're not safe, but what I'm hearing is that riders who have only ridden a bit and are suddenly now buying bigger bikes are significantly at risk."
Auckland Motorcycle Club president Chris Costello agreed older riders were hitting the road unprepared.
"When I was riding when I was 20, which was 30 odd years ago, a 1000cc motorbike would probably do 240km/h, now they do 300-plus and they get there in half the time."
He encouraged motorcyclists to do one of the club's training courses.
Mr Macdonald said the number of registered owners in Auckland City had soared - scooters were up 180 per cent since 2004 and motorcycles up 108 per cent - fuelled by the recession and high petrol prices.
Road policing manager Inspector Heather Wells said the Counties-Manukau police district had a 34 per cent rise in motorbike registrations in the past year,
Two fatalities and 93 injuries resulted from crashes involving motorbikes in Counties-Manukau in the past year, she said.
"And some of those [injuries] were very serious."
Mr Costello said drivers needed to pay greater attention to motorbikes on the road.
"They say the motorcyclist is in the wrong, but car drivers don't look for motorcyclists because they're smaller."
Motorbikes were an attractive option in the city because they were cheap to run and easy to manoeuvre, but that sometimes came at a cost.
* Vehicles at fault
(crashes involving motorcycles in Auckland City):
2004: 6 scooter, 7 motorcycle - 69 per cent
2005: 4 scooter, 12 motorcycle - 76 per cent
2006: 8 scooter, 12 motorcycle - 74 per cent
2007: 8 scooter, 14 motorcycle - 69 per cent
2008: 9 scooter, 16 motorcycle - 61 per cent
New Zealand
