I had the same problem and used a cheap solution suggested to me on head-fi (gasp).  I bought 8 hockey pucks and put them under the spikes.  They are thicker than the spike is long, so the spikes can't go through to the floor.  When I move the speaker stand, the pucks stay on the spikes. 
 
My total cost was less than one Herbie's Threaded Stud Glider.