The one thing that I am a strong proponent of is truing the spoke by shrinking or stretching. The shrinking can ONLY be done with heat. If the rim is trued only using pressure, it will not stay true and you are wasting your money. The theory in this is the spokes must remain in tension all the time to hold the rim in alignment. When the wheel is bent, some piece of metal is stretched. Metal does not have elasticity per se', so just returning the bent area back to the original location does not mean the metal's molecules automatically return to their former position With the stretched metal, the only way to re-tension the metal is to heat and shrink the metal.