As for speed limits on bikes:
"No person shall operate a bicycle in such a way as to endanger hikers, equestrians or others using State Park property, or in such a way as to damage park resources. No person shall operate a bicycle within Folsom sector of the Gold Fields District at a greater speed than is reasonable and prudent, nor in any event in excess of 15 MPH. No person shall operate a bicycle in excess of 5 MPH when passing hikers or equestrians, or when approaching and negotiating a blind turn. Blind turn is defined as not being able to see oncoming traffic from a distance of 100 feet or less."
Also, "The use of Class 2 and Class 3 e-bikes are prohibited on all trails."
To see the original order on the Folsom SRA website, CLICK HERE.