I think you can get away with just springs and I am by no means the expert but I am a big boy so my dirtbike gets a spring rate near where most guys snowbike spring ends up. The general rule with dirtbikes is you need less compression dampening when you up the spring rate and you need more rebound to slow down your new stiffer spring rate. I went this direction on my home done suspension modification with Cannon Racecraft springs. I did a little valve drilling similar to what seemed to work well for me on my 650R when we raced baja and then came up with a little shimstack, I used a few of my go to's out of my suspension box but mostly did a flip flop and I have been very happy with it. We rode last weekend and we don't have a lot of snow which left me dealing with 3 miles of whoops. I don't have TSS on my LT and mine still seemed to be working better than all my buddies Yeti's on KTM's with air compensaters BLA BLA. Mine is all spring no airpro and I took a guess on spring rate by seeing what others were running and their weigh vs what I normally run and my weight. Talked to the guys at Cannon and ended up close to my target with the biggest wire they could resonably make a spring out of and still fit...had to grind the guides and I coil bind at about 3/4 to and inch but thats OK because the fork mount sits there anyway. All and all very happy and my geometry is sitting on a 25 year old frame.
My buddies keep saying I need to drink the Yeti KTM Koolaid but the CR500 works and so does the Timbersled for about 1/3 the cash. I love the experimentation anyway.
