I see 40mph as the safe upper limit for racing; what I should be typing is " gear for 30-40mph depending on how tight and technical your track is. An open or larger track can use the higher gearing/speed more to blow past the other trucks on the straights, where as a smaller or tighter track can use the lower gearing/ speed to make the most of the added acceleration out of bends and along the shorter straights". Ofcourse, thats the long winded version of "gear it for ~40mph"...
