There is a specific procedure to be followed,you don't just "Wear them in".
And Once you've NOT followed the procedure you have to restore the pads
(AND Rotors) surface to Like New before attempting to "Burn them in" properly.
Some thought for your contemplation:
http://bike.shimano.com/publish/content/global_cycle/en/us/index/tech_support/tech_tips.download.-Par50rparsys-0012-downloadFile.html/06%29%20Brake%20Burn%20In.pdf
http://www.vansairforce.com/community/showthread.php?t=28456
And Break In:
Brake pad break-in procedure.
1. After reaching medium speed engage brake pedal to slow car WITHOUT
COMING TO A COMPLETE STOP. Release pedal quickly and do not drag brakes. Repeat four or five times.
2. At higher speeds engage brake pedal to slow car WITHOUT COMING TO
A COMPLETE STOP. Release pedal quickly and do not drag brakes. Repeat five times.
3. At or near high speed engage brake pedal to slow car WITHOUT COMING TO A COMPLETE STOP. Release pedal quickly and do not drag brakes. Repeat three times. Allow a few seconds between brake engagements while car is in motion.
4. Do not hold brake pedal. Park car for approximately 20 minutes or until brake rotors are completely cool to the touch.
5. If during the above steps the brake pedal becomes soft or brake fade is noticed, park the car immediately for approximately 20 minutes. Do not hold brake pedal.
Important reminders:
* Do not attempt to use badly worn or damaged rotors with new brake pads.
* Do not drag brakes while car is moving during break-in procedure.
* Do not engage pedal while car is stopped at any time following the break-in procedure.
* Upon completing the procedure, allow the brake system to completely cool before use.
* Clean a used rotor surface with fine sand paper or steel wool, rinse with water, dry and install before bedding new pads.
I've determined the only safe/sane way to carry out the procedures is late
@ Night on an almost abandoned Interstate.
The first time "50" catches you "Buning In" your new pads it'll help if you have
a copy of the procedures to show Her/Him,otherwise likely to be subjected
to the old Sobriety Test.
The Crazy part of this whole Brake surface prep is that you've gotta get to
your "Prep" area with as little brake use as possible (Can You Say ZERO.)