Computer scientists design wireless bike brake

Say goodbye to protruding brake levers and messy wires, though you'd have to live with three failures in every trillion slowdowns.

In my neighborhood in Portland, Ore., the hipsters all like to ride minimalist fixed-gear bikes (aka fixies). Without a freewheel, a fixie generally requires pedaling forward to move forward and pedaling backward to brake. Brakes with wires are just so last year. Shoot, even handlebars are starting to look a tad frilly.

Holger Hermanns Saarland University

Good thing, then, that a team out of Saarland University in Germany has devised a wireless braking system that does away with those protruding brake levers and messy wires altogether. What's more, the mathematical calculations the team applied to determine safety--the same used in control systems for aircraft or chemical factories--deem the brake 99.999999999997 percent reliable.

"This implies that out of a trillion braking attempts, we have three failures," says Holger Hermanns, who led the group that developed the brake. "That is not perfect, but acceptable."

The cruiser bicycle they used (at right, pretty much as far from the fixie look as possible) includes a fancy rubber grip on the right handle. As with conventional brake levers, the strength of one's grip directly impacts the strength of the brake; if you have to brake hard, squeeze hard.

This is accomplished through a pressure sensor in the rubber grip, which activates a "sender" when a certain pressure threshold is crossed. That sender lives in the blue plastic box attached to the handlebar, which sends radio signals to a receiver at the end of the bike's fork. The receiver then forwards the signal to an actuator, which converts the signal into mechanical power to activate the brake.

The current configuration results in a 250-millisecond brake delay. The computer scientists say they are looking for engineers to help improve brake performance and traction control. Meanwhile, electronic shifting is already on the market, though it ain't cheap.