foam is much cheaper than rubber and better grip all the way to the rim and you don't have to worry about 100's of insert combos/ rim combos and compound combos. And before this starts into a rubber v's foam war I am out of here, I am not trying to start somthing.
for a set of foam's it will cost you about $50 a set of four (rims and foam all mounted up ready to race, and go for 40 front and 35 rear or some call them Pink rear's purples fronts.
coxy.