A passerby reported finding the body on the side of Avenue 50 and Peter Rabbit Lane, east of Harrison Street in Coachella, at 8:03 p.m. on Friday.
Traffic investigators determined that the bicyclist was riding on the Avenue 50 overpass above the Union Pacific tracks when the downgrade caused his bike to speed up. Officials said they believe the rider lost control and crashed into a metal pole.
Riverside County Sheriff's Department Lt. Terrence Tingle said authorities found that the man's bicycle did not have a working brake or a headlight for riding at night.
Officials said there was no indication that other pedestrians or drivers played a role in the crash.
The man's identity was not released pending notification of next of kin.
City News Service contributed to this report.