On the evening of Sept. 2, 15 half-tricycle-half-toilet amalgamations will race through Old City in a blaze of three-wheeled porcelain-god glory. The race will mark the start of this year's Fringe Festival, launching from the corner of Second and Florist streets, just above Race Street, at 6:30 p.m.

Each Toilet Tricycle is custom-built and detailed by artist brothers Steven and Billy Blaise Dufala. The brothers have been holed up in their workshop with assistant Isaac Nichols since early June, ghoulishly fusing plumbing supplies and bike parts in preparation for their great race.

"You might notice that close to 15 bikes around the city have their frames cut in half," Billy Blaise explains, perched atop one of many tables in the Toilet Tricycle workshop, housed in a studio at the Pennsylvania Academy of the Fine Arts. These bikes had been deemed "abandoned" by the city, so Billy and Isaac hacksawed them for tricycle parts. The remaining frame is made of chrome alloy from Dillsburg Airplane Steel, right outside of Harrisburg.

The Dufala brothers see the race as a way to involve people from all walks of life in friendly competition, unified by the crapper. Toilet Tricyclists are of different ethnicities and financial backgrounds, from doctors to art historians to members of the clergy. The brothers also hope to make an example of the Toilet Tricycle race as performance art. "In a lot of people's minds, performance art is rolling around on the ground pretending to be hurt," Billy Blaise admits ruefully. "We see the race as an experimentation of fine art in the public forum. When you bring a piece of artwork into the public forum it becomes a lot more interesting than a sculpture on a pedestal in a gallery."

"A lot of people are going to laugh," adds Steven, but misinterpretation doesn't faze the Dufalas.

The finished product is rather impressive. Each Toilet Tricycle's single detailing can take up to two hours. Some tricycles have shiny silver fenders covering the rubber tires; others are fenderless, but with painted tires. Don't worry about missing details while the Tricycles zoom by: All 15 will be on display throughout the Fringe Festival in locations around Old City. As far as Toilet Tricycle favorites go, Billy says his are #1 and #2. You can only assume why.

Toilet Tricycle Race, Sept. 2, 6 p.m., free, corner of Second and Florist sts. (just above Race St.), approx. 30 min. (Rain date Sept. 3, 6 p.m.)