there will be a number printed on your spring, either 170/185 or 180/185 (the first number is the stiffness ratin in Nm and the second number is the length of the spring 185mm),
the 180/185 is normally found on the SDR and unless you weigh over 14 and a half stone in full kit (or about 210lbs) then its abit too stiff for road riding!
If it is a 180/185 and you wish to swap it for a 170/185 or even a 160/185 let me no as im after the stiffer 180/185!