I raced Trail Bikes (100cc) in the early 70's. Larry, Wes Anderson Jr., Jack Morgan, Terry Clark, Mitch Mayes and a few others were the hot dogs. Jack Morgan was 100cc champion for 5 years in a row. He was NOT a youngster. The Trail Bikes started behind the big bikes, but you would not know it at the finish line.
In the 1969 Barstow to Vegas race, 1000 big bikes started 30 minutes ahead of the 300 trail bikes. Terry Clark finished 55th overall.