I assume your question refers to Sintered or Organic pads. I use sintered front and organic rear. Sintered has flecks of copper or other metal particles in the friction pad, these cut the surface tension of water on the disc so better performance. They are harder and last longer. The organic on the rear are to reduce the rear wheel lock up as they are not as grabby as the sintered pads. Both sets of pads will stop you, I would say experiment with them, my set up is from years of motorcycle brakes, it works for me.