My experience: given every thing else being equal or even similar, an upright position is slower than a lower position, both because of aerodynamics and body mechanics.

Position makes far more of a difference ins speed than bicycle weight does.

I have an upright bike that is at least 30 lbs up to 35 and a road bike that is 22 lbs.

In the last year I spent a lot more time on the upright bike as I was rebuilding the road bike.

When I took the road bike out last spring I was really surprised at how much faster it was for the same or less effort than the upright bike

Commuting I average in the 12.2 to 13.2 range depending on my mood, wind, etc.

On the road bike the average is more like 14 to 15.5

I am a clyde and am not in super great shape right now.

to the OP, I know your concern over bike weight from other posts. ....to take some thing from the road section: it is all about the engine, not the bike, so.....keep commuting and add a longer ride or two on the weekends and in a month or two you will be surprised at how much faster you are

for reference (and because I think they are nice) my bikes...the road is not extreme saddle and stem are pretty much level

upright



road