I don't know if this is old news. But everywhere I see on here shows the old Flex spring rates on 9kg F and 8kg R.
They are now 10kg F and 10Kg R.
They handle quite well on the street, even with damping force all the way up to full stiff.

Auto-x starts next month, so we'll see how they do.

BTW the spring would be marked SL100 both front and rear.