7XL / 9918 savage gearing Q

[RC-Monster Mike]

I didn't check the formulas or anything (assumed it to be accurate, considering the source). What is the actual wheel diameter? I usually figure low 30s for 12 cell setups, mid 30s for 14 cell setups, high 30-low 40s for 16 cell setups, etc. Based on these voltages, you can safely reach higher speeds (obviously you have more available power). According to the calculator, you would be in the low 40s, which should be pretty safe. Especially with a two speed and mechanical brakes.