Vancouver Police say the accident happened around 10:45 a.m. PT. Sunday.
The Granville Street bridge off-ramp and the 1900 block of Fir Street have been closed to traffic.
Police say it was a single-vehicle crash and it appears the man lost control of his bike.
He has not been identified.
Emergency crews remain on scene.
Police say motorists can expect traffic delays in the area of West 4th Avenue and Fir Street as police conduct their investigation.
On mobile? Click here for a map of the affected area