# Cycling power meter with arduino

Hello Everyone,

Since power meters for cycling are Quite expensive ( 800 - 2000 € ), I’m wondering if there exist any way to implement measuring force in pedals of bycicle using arduino??

I want build a simple power metter that would be cheap and easy to implement (add to pedals).

My idea is to put somekind of a senzor on my pedals like we can see here:

http://www.bing.com/images/search?view=detailV2&ccid=ErZWrVkB&id=08836333165FF24C76686C89C409116547621A5D&thid=OIP.ErZWrVkBuME_1fSGqTe6UQEsDH&q=power+meter+cycling&simid=607998041468372372&selectedIndex=0&ajaxhist=0

And then read value from that senzor.

Does any of you have an idea how can I implement it? Or at least give me feedback where to look and what for?

Force does not equal power, so your idea won't work to measure power.

Power = force times velocity.

If the bicycle crank is not turning, you are not supplying any power, regardless of how much force you apply to the pedals.

Andraz23:
Hello Everyone,

Since power meters for cycling are Quite expensive ( 800 - 2000 € ), I'm wondering if there exist any way to implement measuring force in pedals of bycicle using arduino??

To measure power you need to measure (rotation) speed and torque of a moving shaft. The latter is
a hard problem, its basically difficult to measure the mechanical condition of something that is rotating.

If this is an exercise bike (not a real bike) then we can be the load, and measure the torque on the
stationary part of the braking/load mechanism. A strain-guage or loadcell placed appropriately could
monitor the braking torque well, and speed is simple to measure.

Monitoring power to the wheels on a moving bicycle is much harder as that forces measuring a rotating part.. A battery powered wirelessly-communicating device on the pedal would be one way.