Meh.
Last nights solo ride, 68km, 25.6km avg speed, 44.84km top speed. Totally flat except for bridges.
24/38/50 X 18T gearing.

The fast bit is here: https://www.google.com/maps/dir/31.1...a=!4m2!4m1!3e2

Local roadies use that stretch for interval training it seems, I wound up to 40km/hr, and they still reeled me in, perhaps taller gearing would have helped,