Zone system puts the world of power measurement at your feet

Cleat-based technology could mean instant transfer from one bike to another

by Dave Atkinson   July 11, 2011  

Zone power measuring system09.jpg

You might have thought that with cranks, hubs, chains and, more recently, pedals all being tapped for power information that the bike innovators had run out of places to stick a strain gauge. But you'd be wrong: enter the Zone from Dublin-based Brim Brothers, which is a cleat-based power measurement system.

Scheduled to launch 'sometime in 2012' the Zone system uses a sensor array in the cleat arrangement under your shoe, which is wired to a transmitter pod that fits onto one of your shoe straps. There's one for each shoe, which opens up possibilities – just like with pedal systems – for individually monitoring your legs and the balance of power. Like pedal-based power meters it's also easy to switch between bikes; even easier in fact because there's nothing attached to the bike at all, not even a magnet. Assuming you have the same pedals on all of the bikes in your stable, you should be able to hop from one to the other.

The system has a claimed weight of 18g per shoe and uses the ANT+ protocol to talk to bar-mounted computers; Brim Brothers aren't going down the computer route but looking to integrate with the popular systems already on the market.

The system is shown in the release pics as using a Speedplay cleat but sticking to that platform would severely limit the Zone's appeal, so we're assuming that it will work with standard three-bolt cleats when it's released. The makers claim that the sensors don't add any height to the cleat stack so there's no need to adjust your position on the bike.

Sounds good? Yeah, we think so too. The system isn't without its technical issues though, and we'll be interested to see how they're addressed.

The first problem is calibration. Whereas with a Powertap hub or SRM crank the nanufacturer can control the production and fitting of the sensor, that ain't so with a cleat. Plus, different shoes have different material properties, so forces transferred to the sensor may vary. Brim Borthers say that "calibration is really simple compared to existing power meters", so we'll look forward to seeing the process.

Secondly, the calculation of power is more complex than measuring strain at the crank, or the hub, or the chain. This is a problem also faced by pedal systems, because the pedal is free to rotate about its axis. However, while it's simple to implement a system whereby a pedal system can know its axle position, this isn't the case with a cleat-based meter. We're guessing that the Zone will use acellerometers to measure rotational movement and strain gauges for force, but it'll be a complex calculation to resolve all that into useful power data.

That's not to say the system can't work though. We'll be following the progress of the Zone system towards production (along with all the pedal-based systems currently in development), and if we can get a go on a prototype then we'll certainly jump at the chance...

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7 user comments

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Who was it that wrote for most of us using a power meter is akin to hiring an accountant to tell us how poor we are? It can't have been Shakespeare, but it was worthy of him Nerd

simonmb's picture

posted by simonmb [360 posts]
11th July 2011 - 10:00


It's like hiring an accountant to tell you how poor you are...and how to best use your time and assets to get richer.

posted by andyp [1368 posts]
11th July 2011 - 10:27


Is this separate to the system that Garmin are rumoured to be developing?

posted by 37monkey [144 posts]
11th July 2011 - 10:40


Yes, that a spindle-based system from the MetriGear acquisition. Similarly, the date has been pushed back...

posted by mttvrtn [37 posts]
11th July 2011 - 13:54


Maybe they could tap that bloke with the powered pedals for some of his Barclays VC cash. That is if he hasn't spent it all, or is no longer in the country.

simonmb wrote:
Who was it that wrote for most of us using a power meter is akin to hiring an accountant to tell us how poor we are?

"andyp" did, from 27 minutes in the future.

posted by handlebarcam [545 posts]
11th July 2011 - 17:16


sounds a great idea. Minimal weight, easy to transfer from bike to bike and uses existing (ANT) protocol , I hope it is not stratospherically expensive. If sensible money I will be buying it to use with my Garmin 705 - which I just back from being refurbished by the mighty G. And nice and shiny it is too.


posted by pjhwalter [11 posts]
12th July 2011 - 23:35


Looks great if it works!

posted by Bike_Terrorist [13 posts]
19th July 2011 - 17:51