I did it 2 or 3 times in the '80s, on a road bike. Not my good bike but a road bike with 1" wide road tires. Get there early and try to filter your way toward the front of the pack. That's the safest place so long as you don't outrun the traffic control. Expect a bottleneck or two, the first being the bridge from Manhatten to Queens, the second the Verrezano Narrows approach, and the worst one getting on the Staten Island ferry. The best thing to do is park in Staten Island and start from there.