If you're sticking on the ground most of the time .52-.54 springs with stock valving should be fine. If you're going to spend much time jumping .54 or heavier with freestyle style valving is going to work better. This year I'm running a 300 ktm/ SX LT kit with Sxf forks, stock valving and .64 springs to try to maintain a better feel in the initial part of the stroke and still have good bottoming resistance. I picked up a used set of forks off eBay, because I know with my kind of riding there is a really good chance of bending fork tubes and I don't want to trash my expensive forks. I think its a better way to go running expendable forks with heavy springs and no valving instead of dumping a bunch of money into valving and springs on new forks, I just don t see them lasting all that long if you're going to ride hard. Another thing to keep in mind is that the St and LT kits are going to get overwhelmed fairly easy jumping, so if you're not running a SX kit, you shouldn't have much problem with the forks and putting a stiffer spring in should be fine for most people. The kx air forks sucked the first year, ladt year they worked allright if you keep checking the air pressure, this year they look pretty killer but I would still build a cheap set of spring forks because they are going to be really expensive to replace if you bend them.
