Does RunnerBeam support backyard ultras?

Yes. In the event portal, create a loop event with a mass-start cadence, enter the loop distance and the interval between bells (an hour by default), and either set a maximum number of yards or leave it uncapped for a last-one-standing race.

On race day, race control starts the race and the bell schedule anchors to it. A geofenced finish line records every yard automatically, timekeepers can add times by hand, and marshals manage retirements from the yard board in the marshal app.

Spectators follow a live results page built around the bell: the yard clock, standings, the yard board, attrition yard by yard and cumulative time on feet, plus a page for every athlete with their yards charted.