In the year to April 26, 25 people have died on New Zealand roads in motorcycle crashes, compared to 10 last year.
In the 12 months to date, 60 people have died, up from 46 in the previous 12 months, making it the most in a year since 1995, when 78 people died.
President of the Institute of Advanced Motorcyclists Carey Griffiths told Newstalk ZB's Mike Hosking most crashes involved men on bigger bikes, on the open road.
"But it is not really the bike, rather the nature of riding on rural roads."
Keeping motorcyclists safe was a challenge all over the OECD.
"It is a risky activity."
The key was training, he said.
ACC ran a Ride Forever programme, which offered four to eight hours training for learner riders for $20, even experienced riders could get eight hours of training for $50.
Roadsafe motorcycle and scooter training company owner Andrew Templeton told Newstalk ZB's Kate Hawkesby the higher road toll could be due to more riders on the roads this summer.
"Generally we get more riders on the roads in summer, between October and March, and it has been a good summer, so there have been more out than usual."
In his experience male riders tended to play down the risks more than females, he said.
"Female riders would ride within their own skill level, whereas males, especially younger ones, would often forget about the risks."
About 60 per cent of crashes involved rural roads, speeds above 100km/h and bikes above 1000cc, he said.
"So it is down to speed and inattention."
Better training and education would improve safety.
"It comes down to understanding your bike, training, control and being able to read your environment."
The worst year for motorcyclists on New Zealand roads was in 1988, when 146 people were killed.
A Ministry of Transport report published last year found the number of motorcyclist casualties dropped markedly during the 1990s to a minimum between 2000 and 2004.
The lowest number was 28 in 2003.
Numbers increased between 2004 to 2008, and dropped again in the period to 2016.
Motorcyclists make up 10 per cent of all road users injured, compared to around 21 per cent in the early and mid-1980s.
However, motorcyclists now make up about 16 per cent of road deaths, up from a low of 6 per cent in 2003.
Based on data to 2016, 82 per cent of all injured motorcyclists, and 91 per cent of motorcyclist deaths, were males.
The main risk factors identified were decreased stability and much less protection than in a car. Motorcycles are also less visible than a car or a truck.
The New Zealand Household Travel Survey, based on data from 2010 to 2014, showed that on average the risk of being killed or injured in road crashes was 21 times higher for motorcyclists than for car drivers over the same distance travelled.
However, the number of motorcycles on the road had also greatly increased, more than doubling between 2000 and 2016.
The greatest increase has been motorbikes with engines over 600cc, from slightly more than 30,000 in 2000 to more than 80,000 in 2016.
Data from ACC shows motorcycle crashes are about 50 per cent more costly than other road incidents.
In 2016/2017 there were 7412 active claims for motorcycle crashes, including 4035 new claims.
These cost $92,543,636, averaging $12,486 per active claim, nearly $4000 more than the average road-related claim of $8759.
These were out of a total of 51,215 active road-related claims, including 37,772 new ones, costing $448,601,417.
The recent increase in motorcycle fatalities comes in one of the worst periods on New Zealand roads in over a decade.
The road death toll overall to date this year sits at 129, up from 115 last year.
In the past 12 months 394 people have been killed, up from 334 in the previous 12 months.
The last year higher than that was in 2007, when 421 people were killed.
