Congrats on yer Trek!
Many factors go into speed, the 7.7 is higher geared than my bike AND it's tire width seems closer to road than mine. All of which seems to point to a more "road" focus than a lower geared bike with wider tires. Head or tail winds (at least for me) also play a BIG role... I can go one direction and barely average 12, while on the way back it's more like 15 average. Are you on the largest front chainring?