The crash occurred around 8:20 a.m. on northbound Almaden Expressway and Branham Lane, Officer Jose Garcia said.
The motorcyclist was riding a Harley Davidson behind a white pickup truck in the No. 3 lane just before the crash happened, Garcia said.
As the truck slowed down and started to turn right into the parking lot of a business, the motorcyclist swerved to the right of the truck, lost control and drove through a wooden fence and into a curb, Garcia said.
He was pronounced dead at the scene, Garcia said.
The driver of the truck, a 47-year-old San Jose man, was not cited and did not appear to be under the influence of alcohol, Garcia said. He was not injured in the crash.
Northbound Almaden Expressway north of Branham Lane will be closed until about 12:15 p.m., Garcia said.
