[theprgramerdude]

Frankly, the easiest way to reach >= 20 FPS is, besides throwing on more motors, NOT approach the 120lb weight limit (which, when adding in the bumpers and battery, goes to the limit of about 150 lbs). Since F=MA, and V=int(A(t),t), Shaving 20 or 30 pounds would be a huge boost in acceleration, and thus make it possible to reach those speeds within the length of the field.
Taking our 2011 robot as an example, it only had sprockets+CIMple boxes as a reduction, while weighing about 110 pounds competition-ready, it accelerated faster to higher speeds than our similar robots in the past that hit the 150 pound mark, but had higher reductions to get similar acceleration up to their lower max speed.