I did it last thursday afternoon. Too crowded with tourists and too dangerous down the southern end of the park to get a decent ride in, so I bailed and went over to the greenway where I had less of a chance of crashing into a tourist on a rented bike. FWIW we saw one rental with a trail a bike that looked like it was about to fall off the bike it was attached to. Unless you can get out early morning or late evening its better to steer clear of the park loop, at least until October.