Indian Motorcycle, the first American motorbike manufacturer and a mainstay of the motorsport for the first half of the 20th century, has been going full-throttle since its return in 2013—and the new 2016 Indian Scout Sixty is the latest feather in its headdress. Based on the popular Scout model that debuted at the Black Hills Motor Classic in 2014, the 542-pound Scout Sixty has the look and feel of the latter, while being friendlier to first-time riders.

Still a powerful performer, the 999 cc midsize f…