Does anyone have trouble with bottoming out their bike on the mx track? I ride with 18" rear holeshot mx's and 19" front mx's. Stock shocks with the fronts set to the highest compression and the rear left at factory setting. I know im losing a bit of clearance from the smaller tires. Are these tires too small for the rappy? Is this common? Is this going to destroy my bike(frame, etc.)? Thanks...

 

Bottoming out a little, maybe once per lap, is normal. More than that, or bottoming HARD is bad. It will wear you and your quad out. The stock shocks are too soft for a heavy or fast (high flying) motocrosser. For a cheap solution - buy some Works triple rate shocks for the front and increase the damping compression on your stock rear shock. Total cost, about $350. Or for a better solution, buy a full set of Elka shocks. You get a lower center of gravity and 1-2 inches more travel. Total cost about $1800. Or for the best setup, buy the Elkas AND a set of Lonestar +2 a-arms and a Lonestar axle, and a Lonestar +2 swingarm. Total cost about $3500. Good Luck!

RR1

 

I have Works shocks on the front and stock shock in the back of my Rappy. I have no problem with bottoming out and I'm a big boy..200+. The stock fronts were a little too soft for my liking.

 

You need to specify what "bottoming out" is. Traditionally its associated with suspension. Which what you got for one response. From what I can tell you're talking about ground clearance. In the cheap solution, raising the preloads stiffen the spring and result in less sag, but you wil sacrifice any type of suspension adjustment just to make it have more clearance.
I race at the notoriously sandy MX338 in Southwick, MA, where its always huge ruts. I run the same tires there as I do on the hard pack which is the same size as you're running now. When the ruts get real deep I do drag. I don't run the rear skid because it tends to make you float on top and not get your tires to the ground. Drawback is that I eat up chains and rear sprockets faster. If you are having real problems the obvious solution would be to run larger tires. Maybe a 20 in the rear and Holeshot does I'm pretty sure have a 20" front in the mx version.
If you're addressing suspension bottoming out. Just do a search, its been talked about forever on here, everyone has their own opinion, just get your wallet out. Good luck.