power meters

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Cuchilo

Prize winning member X2
Location
London
Such a comparison would probably result in different readings for all those different systems anyway (as pointed out elsewhere in the thread), so that would not prove anything unfortunately.
Well thats probably why it was looked at in the design stage and why the person that knew about these things told me about it .
 

S-Express

Guest
Sorry, you've lost me again.
 

MistaDee

Active Member
No , the way it was explained to me was that not all of the power you put out is in one direction . Linear , that's what a pedal based system reads . Any pressure or power out of that one direction is lost and will also add wear making it worse over time . This information was from someone that worked designing power meters among other things .
If the information is wrong then i'm more than happy for it to be corrected as i am still looking at power meters myself . From what i have heard stages crank based would be the safest long term buy .

I understand that the Garmin vector does not read linear as doing so would prevent it from displaying Platform Centre Offset data which it is capable of doing remarkably well.
 
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S-Express

Guest
That doesn't seem to be hard to do .

Ha ha - a comedian.

Well, maybe if you had been clearer, or perhaps were in posession of a little more knowledge. All you need to do is explain what you mean by 'linear' power delivery. Perhaps if you could clear that up?
 
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screenman

Squire
My eldest and his wife both use power meters, but they were coached and tested to find the correct power to train at.

My son being a mathematician loves the numbers, my dil loves winning and feels
the pm a useful training tool.
 

jiberjaber

Veteran
Location
Essex
You'll find a good description (though slightly out of date with the present market) on how it all works here:
http://bicycles.stackexchange.com/questions/5612/how-do-bicycle-power-meters-work

What is being called (none) linear is really about the impact of force on the pedal, crank, BB and how it deforms (twisting/bending etc) these components, so to get the full power output you need to measure all the vectors the force acts through all the way through the pedal cycle, clever alignment of strain gauges etc help ( because of the way they work, https://en.wikipedia.org/wiki/Strain_gauge ) but it's perhaps not economically or technologically viable to cover the object in enough orientated gauges to capture all the vectors of forces in action all the time, so a compromise has to be made with some clever maths to fill in potential gaps.

The key thing as pointed out by them that has 'em is consistency, regular interpretation / tracking of data trends and testing to establish a baseline (FTP / power at various durations).

There's plenty of guides out there on how to use power meters effectively either for improvement or pacing etc

Battery life with Vector 2 has the same issues as Stages in that it is very effected by temperature, in the winter with temp <7 degreesC I was lucky to get a 200km ride out of a set of batteries sometimes. Presently I am getting over 1000km on a set of batteries. I also suffer from occasional inconsistency in balance between left and right measurements - the root cause of which is often obscured as anyone who has any Garmin product will know, we are all their beta testers! LOL
 

Bollo

Failed Tech Bro
Location
Winch
You'll find a good description (though slightly out of date with the present market) on how it all works here:
http://bicycles.stackexchange.com/questions/5612/how-do-bicycle-power-meters-work

What is being called (none) linear is really about the impact of force on the pedal, crank, BB and how it deforms (twisting/bending etc) these components, so to get the full power output you need to measure all the vectors the force acts through all the way through the pedal cycle, clever alignment of strain gauges etc help ( because of the way they work, https://en.wikipedia.org/wiki/Strain_gauge ) but it's perhaps not economically or technologically viable to cover the object in enough orientated gauges to capture all the vectors of forces in action all the time, so a compromise has to be made with some clever maths to fill in potential gaps.

The key thing as pointed out by them that has 'em is consistency, regular interpretation / tracking of data trends and testing to establish a baseline (FTP / power at various durations).

There's plenty of guides out there on how to use power meters effectively either for improvement or pacing etc

Battery life with Vector 2 has the same issues as Stages in that it is very effected by temperature, in the winter with temp <7 degreesC I was lucky to get a 200km ride out of a set of batteries sometimes. Presently I am getting over 1000km on a set of batteries. I also suffer from occasional inconsistency in balance between left and right measurements - the root cause of which is often obscured as anyone who has any Garmin product will know, we are all their beta testers! LOL
The stack exchange link is worth a visit just to see the first SRM power meter. Frankenstein's crank!
 
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