i ride a ktm 530 08 model and run a 8.4 rear spring and 5.0 fork springs and wieght about 104kg have found with the heavyer springs can hit big bumps harder but is harder on the arms after a ride may need a revalve but am to tight .tecknics will sell you the correct springs for your weight just give them a ring not cheep but just tell them your weight you will need fork springs to .if your bike is older than 08 the rear spring rates are different than what i said different set up