|Rode it like i stole it|
1. Tires make a difference
My mountain bike has grippy front tires and less grippy rear tires, but they are still dirt tires built for the single track or mountain trail. Unlike the slick road tires those guys who passed me use on their roadies, mountain bike tires have more rolling resistance, causing me to output more power on the pedals to go as fast as them.
2. Lockout your front suspension (if you can)
The lockout feature on your front fork is not just a gimmick to make your bike $$$ more, it is meant to be there because you need it in some circumstances. The lockout is good for riding smooth trails with loose sand or dirt... and asphalt with non bumpy roads. I tried riding around my house on my training sessions every morning with my lockout unlocked (suspension on), and it was fine most of the time because I go through the small alleyways with ups and downs, speed bumps, and some rocky roads thrown in just for fun. But it makes the bike rock up and down when you pedal hard on smooth surface, so its best to lock your front fork when you ride on road on your MTB.
3. Keep your seat high
Proper seat position is key when riding your bike. It makes your body feel less horrible after you finish your ride. I usually ride with my seat a bit low so i can easily let my feet down if the road gets to bumpy and I'm about to fall down, or there is a grandma on a motor bike full of bottled water on the other end of the alleyway demanding that she goes through first. This morning I rode with my normal seat position, it felt okay, but you can notice the difference after you've ridden about 5 k on the bike and you need more leg room so you can be more efficient on your pedal strokes. Unfortunately I did not bring my allen wrench to adjust my seat position.