A university study has found flaws in the data on which the Government based an ACC levy rise for motorcyclists.
The annual levy for large bikes has been raised by almost $200 to more than $400.
Associate professor Charles Lamb of Lincoln University says the increase was based on an ACC claim that motorcyclists are to blame for 87% of the crashes they are involved in - but according to his analysis of the data the actual figure is between 50% and 55%.
Mr Lamb says motorcyclists make up only 2% of ACC claims, yet they pay more than any other non-commercial road user.
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