Originally Posted by kabex

I'm no expert but your legs aren't extending enough also you have a very upright position, I'd raise your seatpost to the point where your leg extends 90% when the pedal is at 6 o'clock, or by placing your heel on the pedal, it should extend 100% at 5 o'clock.

Also get the stem as low as possible and see how it works for you, try it for a few rides and you can adjust to it.