A Norristown man who admitted driving recklessly and causing a motorcycle crash that left his female passenger dead has been given 11 1/2 to 23 months in Montgomery County Prison. 21-year-old Julian Mansfield of Swede Street pleaded guilty to homicide by vehicle and other offenses earlier this year.  19-year-old Ryan Bonita Banjoman of Norristown flew off the seat and into the Schuylkill River when Mansfield hit a concrete guardrail on the Dannehower Bridge on Route 202 in June of last year.  Investigators found that Mansfield was going at least 74 miles per hour when he tried to pass a car on the right side and struck a concrete barrier.