Don't know what I did differently. But I set a new average speed record for myself today.
For weeks, I've been unable to beat 12 mph on the Mount Vernon Trail. Today I averaged better than 16 mph. That's unofficial -- since the official speed limit on the trail is 15 mph.

Not a lot to brag about -- except I'm still figuring out how to ride. And, as one of my riding buddies cracked at me a month back, "Nice mountain bike. What's it weigh, about 500 pounds?"
I gave her a dirty look. Looked back at the bike on the rack on the back of the Mustang. Then looked sheepishly at her and asked back, "Would you help me get it off here. I can't lift it by myself."
The lack of a headwind and the fact the tires were at maximum pressure are the only things I can credit with the improved speed. Stayed off the streets in Old Town, and that probably played in my favor.
I set off from Roosevelt Island. That's my car and bike before the ride.
18 miles/1:05 hours
Temp: 70 Sunny
Winds: Calm