Cleat-based power meter takes a step forward

Brim Brothers has taken another step toward releasing a cleat-based power meter

The sensors are inside the cleats themselves. A small wire runs from the cleat to the brain pod.
The sensors are inside the cleats themselves. A small wire runs from the cleat to the brain pod.

Brim Brothers, a Dublin-based group of engineers bent on producing their own cleat-based power meter, has taken another step toward that goal. The company announced Monday morning that the new meter now has a name, Zone, and released photos as well.

The power meter, which we first wrote about at Interbike last year, uses piezoceramic sensors inside a cleat, in this case one from Speedplay, to measure force. That data is sent to a “brain” that sits on top of the shoe (and out of harm’s way), which can then do all the necessary computations and send the data via an Ant+ signal to a head unit.

The brain also includes sensitive accelerometers, necessary since accurate position data of the foot is vital to the calculation of power (power=torque multiplied by angular velocity). One Zone pod goes on each shoe, and as a result power can be measured from each leg independently.

The brain pod separates from its base and is easily removed from the shoe for charging or upgrading firmware. The sensors go inside the cleat (but don’t add any height), and can be walked on without fear. The system knows the difference between walking and riding forces, apparently. It is also completely waterproof (see the photo from Brim of a shoe in a bathtub), and adds only 18 grams to each shoe.

The cleat sensors are easily and cheaply replaced (though no word on exact pricing yet) when the cleats themselves wear out.

For those with multiple bikes, the system promises to be the most useful to date, negating the need to swap wheels, cranks, or pedals around. Just don’t swap shoes.

Brim Brothers representives still refuse to set a firm release date, only noting that their goal is to release sometime in 2012. “We’re going as fast as we can, but we still have a lot of careful testing to work through,” the company said on its blog.