Laser Spoke measures cyclists' power output
Laser Spoke measures your pedaling power
Modern electronics have given us the means to measure nearly every part of our performance – speed, distance, vertical, heart rate, etc. But there are still other variables that go unmeasured by the average athlete. The Laser Spoke provides a simple aftermarket solution for tracking cycling power.
The Laser Spoke is a universal digital measuring device that fits the rear wheel of everything from BMX bikes to road racing bicycles. It measures power, passed from your legs onto the drivetrain and wheels of the bike, at the spokes of the rear wheel through a laser-based optical system. The designers chose to use the rear wheel, as they say it acts like a torsion spring, twisting in response to the applied torque. The Laser Spoke measures the amount of twist, to give you a power readout.
The system consists of a laser and position-sensitive detector mounted on the hub, and a right-angle prism attached to the rim. In operation, the laser fires its beam at the prism, which then casts it back upon the detector. The detector produces an electrical signal that is proportional to the position of the laser beam, the beam deflection and the applied torque.
The Laser Spoke currently stores data by way of an SD card, but the company plans to use a removable USB module with flash memory. It is also working on an ANT + interface for the device that would allow for wireless communications with ANT + monitors.
Laser Spoke says that its system is less expensive than existing power monitors. It claims the system is accurate and, because it uses optics instead of moving parts, is more durable in the long run. Plans call for a final module that weighs no more than 150 grams (5.3 oz).
Laser Spoke is currently looking for funding on Indie GoGo. The company has its first prototype built and is trying to raise money to further develop it into a production-ready model.
Source: Laser Spoke
About the Author
Upon graduating college with a poli sci degree, Chris toiled in the political world for several years. Realizing he was better off making cynical comments from afar than actually getting involved in all that mess, he turned away from matters of government and news to cover the things that really matter: outdoor recreation, cool cars, technology, wild gadgets and all forms of other toys. He's happily following the wisdom of his father who told him that if you find something you love to do, it won't really be work.
All articles by C.C. Weiss
This system offers high accuracy and low penalty for a reasonable price. An option for a wireless real-time display would be a nice option though.
This idea is merely a replacement from external hardware to internal hardware for the bike.
Sounds like a complex solution where one already existed. A sturmey archer dynohub and a turnigy wattmeter.
Or you could use the accelerometer on your droid/iphone and use basic kinematics equations in an app.
Reminds me of the American development of the space pen that wrote upside down in zero gravity - for a million bucks. Apparently the Russians just used a pencil....
One previous method of measuring rider power output and which offered more information in real time via a handlebar display was, if my memory serves me, was made in France. It meant a complete crankset replacement with magnetic sensors and
wiring attached to the frame. It measured the amount of deflection of one or both pedal arms under load, plus any non-rotational movement of the crank axle.
It wasn't something the average club cyclist could afford as the system was a couple of thousand dollars 12 years ago.
I assume this system will work on all wheels with different spoke tension and rim strength. One point on the rim (right hand prism) seems a less accurate means of measuring output in watts, compared to say having 2 or 4 prisms with a corresponding number of lasers. More would add to the cost, but I
believe, this would increase accuracy at slower wheel rotational speed i.e. hill climbing.
Storage of info from the road or in a lab via an SD card is a given, but what I would like to see are a number of apps that are Windows 7.5, Android 4.0, iPhone compatible so that users only need mount one display on the bike.
If the 'Laser Spoke' comes in under $400 the unit will sell in the millions. Need colour choices also. Great concept.
Hmmmm....weak since it offers nothing more than existing systems. I doubt it will cost much less too, but that could be a benefit. The limitation of this system and the two current mainstream existing systems (crank based or rear hub based) is that you need a complete setup for each bike you own or ride/train with. Powermeters are not being used by recreational cyclists, and serious cyclists owns multiple bikes. These things cost $1500 and up, in addition to the wireless GPS device you need to display your data (typically around $300). This unit can off course be used on multiple bikes.
Garmin is working on a solution to create PEDAL based powermeters. It is not just possible, but actually pretty easy and just a minor inconvenience to move pedals from one bike to another. The cleat setup for these pedals are of the road type (not mtb with Shimano, Time or Egg-beater cleats) but can be used on an mtb if you are riding terrain that would not require you to dismount too much (like when riding mostly non-technical trails or rail trails and fire-roads). With road cleats it's pretty hard to negotiate walking up rocks. A pedal-based power solution is really the most versatile. Hopefully Garmin can get it right since they've been delaying the release of the pedals for over a year now.
We have some great news to share! I’m happy to announce that Laser Spoke ltd has applied for an Invest Northern Ireland grant (£50K) to run research and development on this project.
We have reviewed carefully our budget taking into account this serious government support and success of our IndieGoGo campaign. We are able now to introduce new prices for our perks for the period of this campaign.
We want to invite even more people to our project. Please share this great news with your friends, cycling clubs and welcome.
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