Direct Hit Not Required
Join Date: Nov 2003
Location: San Bruno, CA
Bikes: Leopard DC1, Ridley X-Fire, GT Zaskar 9r
CycleOps Fluid2 units don't use spring pressure against the tire, it has an adjustment knob that turns a screw to tighten the unit against the tire. I don't know about older CycleOps Fluid trainers.
On my Fluid2, the side of the roller opposite the resistance unit has fins that blow air over the resistance unit to constantly cool it during the workout. Even after an hour long Spinervals tape, my resistance unit is warm but still touchable, certainly not hot enough to burn dust or other debris.