Mike the Bomb 1's work best on the wet high grip clay (like at LHR early in the day), but the stock foams (losi) work better once the track drys out a little bit. I have have ran both foams, and I have found that the stock losi foams work better. For the outdoor track do not use the bomb 1's as they are way to firm for that surface, as the bomb 1's work better where you would want the foam to support the tire (places that are of very high grip, "sticky" dirt that is hard packed).
