I don't have a speedometer on my bike, but my mom has one on hers, so I took her bike out today to see how fast I could go. With no wind, about a block and a half of running distance, and a slight (maybe 10 degrees) inclination I could get up to 25 mph. One would think that coming down the hill would mean I would go faster, but no, I still got up to the exact same top speed. So I went out to find a bigger hill to go down, and in doing so I found a hill that got me up to 35 mph. Hooray. Too bad my mom's bike is way too small for me and I couldn't go anywhere near as fast as I can on my bike.
Goal for today: Get speedometer.
Moral of story: falling off a bike at 25mph whilst unprotected is dangerous, do not do so.