Timeline for Does a crank arm Power Meter measure power in both directions?
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
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| Sep 8, 2016 at 17:07 | vote | accept | AzulShiva | ||
| Sep 8, 2016 at 10:44 | comment | added | alexsimmons | A simple test of this is done by inspecting the torque zero offset values (a simple process for many power meters) then applying a positive or a negative torque and to watch the reported torque values. In the case of my SRM (and on Quarq and Power2Max) spider based power meters, the torque values move up for positive torque and down for negative torque. | |
| Sep 8, 2016 at 9:51 | comment | added | alexsimmons | Yes, well designed strain gauges can differentiate the direction of force application, or alternatively distinguish between positive and negative torque. Indeed depending on the design of the gauge set up (e.g. Axis cranks) they can provide such bidirectional force data in 3 dimensions: tangentially, laterally and radially, although most meters just focus on measurement of tangential forces. In case of radial forces, that's akin to distinguishing between compression and tension. | |
| Sep 8, 2016 at 8:45 | comment | added | AzulShiva | That's one hell of a reply but I believe there has been a misunderstanding. With >>measure power in both "sides"<< I did not mean left foot, right foot. I have edited the question now. The strain gauge inside a power meter will change electric resistance when it bends. The question was wether a simple crank arm power meter can differenciate wether it's being bend one way or the other. Because according to my logic if it can't we've got some serious problems that I have already adressed in my question. | |
| Sep 8, 2016 at 8:11 | history | edited | alexsimmons | CC BY-SA 3.0 |
added 9 characters in body
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| Sep 8, 2016 at 8:00 | history | answered | alexsimmons | CC BY-SA 3.0 |