We know full well that for many out there the ultimate trail bike needs to possess the agility and responsiveness of a 650b trail bike we tend to agree which is why were proud to introduce the s works stumpjumper fsr 650b it reflects everything that weve learned over the years and in our eyes represents the pinnacle of trail performance starting at the carbon layup it features our highest end fact 10m for an ultra lightweight strong and stiff construction the carbon moulding process