What does FSR stand for in mountain bikes?
As per the Specialized web site Future-Shock-Rear.
According to Mountain Bike Rider,
In case you were wondering what the ‘FSR’ acronym means, technically it means ‘Front Suspension and Rear [suspension]’. This is historical acronym that dates back to when suspension forks came out (Stumpjumpers with sus forks were dubbed ‘FS’). When rear suspension came along, they added the ‘R’, hence ‘FSR’.