Deputies said he crashed after he gave the finger to a woman he was passing.
A woman told authorities she was driving north when the motorcyclist passed her suburban on the right and gave her the finger. He then turned around and did it a second time, but lost control and crashed.
"After he gave her the finger a second time, he lost control, hit the curb and struck his head," said Harris County Sheriff's Sgt. Dashana Cheek-McNeal. "He was unconscious at the scene."
The motorcyclist was taken by Life Flight the hospital.
Deputies said the other driver did not strike him.