From the Anadarko [Oklahoma] Daily Democrat, May 29, 1902.
This article, reprinted from the Chicago American, describes the effect of centrifugal force, (which I thought was centrifical force but that's apparently not the better term) on a cyclist in a high speed loop. I should admit, I'm not sure if the 1902 physics is correct or not. The same article appeared in the North Platte [Nebraska] Tribune, May 16, 1902 and the [Louisiana] Jennings Daily Record, May 26, 1902 - it was fairly common for human or general interest articles to be reprinted in this way across the country.
The bicycle "loop" presents a most interesting demonstration of a great scientific principle, which plays its part in preventing the earth from dropping into the sun, and the moon from being precipitated upon the earth, no less than in keeping the rider and his wheel from falling to the ground when he hangs, head downward, In midair, at the top of the loop.
A different article about a particular example of such a loop-de-loop was published that same year around the same time in the Cook County Herald, May 17, 1902 (Grand Marais, Minnesota). The second article is more interesting for a cyclist since it describes the particulars of his bicycle.
A group of circus men, newspapermen and photographers last week saw a dare-devil bicycle rider loop the loop at Coney island. With no other aid than the velocity accumulated by a rush down a steep incline the man rode up the concave surface until he hung head downward and continued on down out of the loop to dismount, cool and collected, 100 feet away. The bicyclist was Robert B. Vandervoort, an electrician, who has gone over the loop-the-loop railroad known to almost every visitor to Coney Island until he has come to look upon centrifugal force as a real, tangible thing.
Vandervoort's wheel is one especially constructed for the daring ride. It weighs about sixty-five pounds, has pneumatic tires on broad rims of steel, no pedals, no chain or gearing and no brake. There is no way for the rider to stop himself once mounted and in motion, except to fall off, and there is no mechanism to allow of the rider's attaining motion. It has two footholds for the rider's feet, where the crank shaft os a bicycle usually is.
The same idea, but running rather than riding a bike ~