I have heavier hybrid than yours, and with front susspension. 1 mile in 3:30 is around 17 mph. I averaged that on a 25 mile night ride on unpaved country roads with my group, but it's not the type of riding I like.
When I ride alone, I average 12-14 on most of my rides, which on average is around 40-50 miles. Even century rides are around 12-13.
If I was looking at the average speed for 1 mile only, I could easily say 26 mph...which would be around 2:15
But that would be faking your average speed...there is no way to keep that average speed for long, on a regular bike, and with a regular rider...