1998 Honda CBR 250 RR "change rear spring 2010" Questions

Rear STANDARD shock spring, = 54NM-5.7KGF.. Adjustable RANGE is 126mm-138mm (thats the TOP of the BOTTOM adjusting nut ('C') to shock top mount bolt centre) Its already set to 118mm..from shop

...rear you can add a shock position lower kit to get about 1 inch using stock shocks(approx. $100) and medium skill. Changing for shorter shocks or air adjustable can gain even more lowering($400-1400) ...