Hydraulic Disc Brakes Not Locking Up
New brakes need to be "bed-in" (not bled), with their rotors: Get up to speed, then drag the brake for 5-6 seconds (builds up heat) and then increase lever pressure until the bike stops. Do this about 10 times.

More on bedding-in brakes here:
http://www.bikeradar.com/us/gear/article/how-to-bed-in-disc-brake-pads-31337/