About half of the Riv staff takes Bart, the local train system, into work. The train cars have a dedicated bike zone but unless you're standing up and holding your bike, the acceleration and deceleration of the train will make it roll away and tip over. Bart provides webbing and buckles to secure your bike to a railing, but they're bacteria traps and nobody wants to touch them. Plus, even if you use the webbing, your bike can still slide back and forth. These parking brakes are easier to use and work better.
With the front brake locked you can relax and read without worrying about your bike rolling away, and when it's time to go, you can cinch it tight on your bars so it's always there when you need it.
I (James) sometimes use one to lock the front wheel while my bike is leaned up against the wall so it doesn't roll away or flop over. It can also stand in as an extremely low security lock in a pinch like if you have to lean up your bike at the cafe and can see it through the window.
My first bart brake was a gift from Matt Feeney from Pass and Stow Racks. Rich swears by this plastic one made by Blackburn in the 90's. Sometimes Will uses a Casio or an irish strap. Really, you can do it with about any strap-like thing but this one is made by me with a nice zinc adjuster and one of three fun cord colors (picked at random)
