Do the forks bottom out when you brake hard? How much travel is left after you sit on the bike (have someone measure the sag when you sit on the bike (what was it and what is and add this to the amount of sag without you (lift front end with jack and measure fully extended and then again with the bike on its wheels sitting vertically.) If you have 5" travel in total you should have 3.5 to 4" left with you on the bike. If you have less than this add spring spacers to raise the bike. If it still bottoms when hitting the brakes or when hitting a bump, you need stiffer springs.