The 27-year-old was involved in a collision on Cawthorne Road, at around 12.30pm.
The rider, who was on a green Kawasaki, is believed to have been heading downhill towards where the road goes under the M1, when for unknown reasons he and his bike left the road - no other vehicles are thought to have been involved.
The rider was taken to hospital but he died from his injuries.
South Yorkshire Police are keen to hear from any who witnessed the collision, especially those with dash-cam footage.
Call 101 quoting incident 327 on May 2, or email footage to firstname.lastname@example.org quoting the incident number in the subject title.