Salsa mtb * 3, Intense mtb * 1, Abeni SS rd * 1, Salsa road/touring * 2, Trek Damn one * 1, Vintage/projects * many
A common reason for this type of suspension adjuster to stick is that it has been turned and jammed all the way in or out against a stop. If this isn't the case, the knob might need to be removed and cleaned out, then re-attach and try to turn the shaft.
Most likely though, an internal part has seized or broken and it needs to be returned to the service centre.
Yeah been reading and found this is common with the 2008 FSR brain -- hoping my friend at the local Specsh dealer can "help" with an upgrade, this bike is fun so I want it ride right, perhaps custom tuning is in order for my 200lbs of mass.