Since I got my first road bike a few weeks ago, a used Trek 1500SLR for $450, I've been itching to time myself on a ride to gauge my base speed so that I can properly set realistic goals. Rode a few times through the city with way too many stop signs and lights, and did one hilly ride through Griffith Park with a couple friends, but one of them was pretty slow so had to wait a bunch.
Finally found the LA River Path which is 14.4 miles RT or so of non stop riding (except for a stop and turn at the far end and a couple emergency brakes for kids with tricycles). Wind was < 5mph which was great. Tires were soft though, maybe 30 psi, tried filling at a gas station but my presta adapter wouldn't fit. Bike pump should arrive via UPS tomorrow, hopefully.
I have some base cardio from hiking, so from reading some threads, it seems 20mph is a good number to shoot for. Wasn't easy but barely got it by the skin of my teeth! Let's see next week if the tire pressure makes a difference. Odometer on the bike rolled over 100 miles at the beginning of the ride so I guess I'm officially a cyclist.
http://connect.garmin.com/activity/164633698