My average speed during a zone 2 ride outdoors is usually around 27 to 30km/h and I ride on a pretty flat surface(100km distance with 600m elevation). I am using the garmin vector 3s pedal and it has zero torque after calibrating before each ride. What I noticed is that the riders who are based in the same area as I live have a higher average speed with the same power I produce and range from being lighter than and heavier than me(for reference my weight is 65kgs, my FTP is 4.8w/kg and 315w in terms of power).
I had a giant propel advanced 0 2016(an aero bike) which I sold and now have a trek emonda alr 2019 and I did not notice any difference in average speed during a zone 2 ride so I might have to rule out the factor that it is my bike which is slowing me down. I have tried getting aero on the bike but still it didn’t make any difference. I would like to know some other strategies used to increase average speed. I am also aware that it depends on the terrain.