quick ? about my 06 crf450r rear shock spring.

[thecount]

I have a 06 crf450r and the suspension is done by pro-action.my question is the rear spring rate i a 5.3 and stock is a 5.5 why would they go 2 sizes smaller on the shock spring.my fork springs are stock and i weigh 185 ponds.I bought the bike from a buddy and he cant remember how much he weighed at the time of the revalve.we both ride the same pace and tracks so it should be close.I have a issue with the shock wanting to kick me over the bars at times and i have put the rebound on the shock at 6 clicks out.please help and give your opinions thanks

[mog]

does it kick worse since the new spring and what are your sag numbers?

[thecount]

sag is at 100mm and have only rode it with the black spring it's a eibach 5.3.i have to have my rebound set 5-6 clicks out.have not rode with the stock yellow spring yet.

[mog]

whats the free sag.