Shimano R9100-P Powermeter

[Pierre86]

PMs that have more accurate dual sided readings and are cheaper than the R9100-P - which are those then?

The Quarq and Power2Max are outright cheaper but they don't have dual sided readings.

Strangely enough even my old quarq riken records dual sided, maybe you should look a little harder into your p2max because I imagine it should too:
Handcrafted in Germany, power2max power meters deliver Industry-leading precision, data richness, dual-sided power metering and exceptional performance together with both ANT+ and Bluetooth Smart connectivity.

And what if you don't want to have to change your pedal system? I run two bolt (most of my miles are stop start commuting and I would wear out road cleats/shoes in no time) so current pedal systems are pretty much a non starter, although I see SRM now have an (expensive) SPD option, and IQ2 have one coming although who knows how accurate that will be

What do you actualy use your PM for?

[TobinHatesYou]

PMs that have more accurate dual sided readings and are cheaper than the R9100-P - which are those then?

The Quarq and Power2Max are outright cheaper but they don't have dual sided readings.

Strangely enough even my old quarq riken records dual sided, maybe you should look a little harder into your p2max because I imagine it should too:
Handcrafted in Germany, power2max power meters deliver Industry-leading precision, data richness, dual-sided power metering and exceptional performance together with both ANT+ and Bluetooth Smart connectivity.

Spider-based power meters only measure total power, not discrete left/right power. They measure changes in AV and torque loads to estimate your L/R balance and it's not very accurate.

[Pierre86]

Spider-based power meters only measure total power, not discrete left/right power. They measure changes in AV and torque loads to estimate your L/R balance and it's not very accurate.

Seems more accurate than the shimano at the very least, I at least get 100:0 when doing anything single legged. Also on magneted cadence as opposed to derived which should be more accurate

[ruklaw]

And what if you don't want to have to change your pedal system? I run two bolt (most of my miles are stop start commuting and I would wear out road cleats/shoes in no time) so current pedal systems are pretty much a non starter, although I see SRM now have an (expensive) SPD option, and IQ2 have one coming although who knows how accurate that will be

What do you actualy use your PM for?

Same as most people, Navel Gazing.....

I use it to track my fitness (using Xert) and to pace my efforts. I also use it for intervals on my Elite Turbo Muin.

[ruklaw]

Spider-based power meters only measure total power, not discrete left/right power. They measure changes in AV and torque loads to estimate your L/R balance and it's not very accurate.

Seems more accurate than the shimano at the very least, I at least get 100:0 when doing anything single legged. Also on magneted cadence as opposed to derived which should be more accurate

That's interesting, but it would cost 50 euros to upgrade my NGEco to show this data, and it's not really a metric I'm interested in - like, if you know you have 60 40 balance, what do you do with this information? Has anyone shown balance work to benefit total power output?

[Maxxlefty]

Sorry, but when you calibrate the powermeter does it happen every so often that it gives an error and the red led flashes?
It happens to me occasionally with two models both with the latest fw.

[BigCol]

Sorry, but when you calibrate the powermeter does it happen every so often that it gives an error and the red led flashes?
It happens to me occasionally with two models both with the latest fw.

I've never had that happen with mine

[Maxxlefty]

Sorry, but when you calibrate the powermeter does it happen every so often that it gives an error and the red led flashes?
It happens to me occasionally with two models both with the latest fw.

I've never had that happen with mine

firmware version?

[BigCol]

Sorry, but when you calibrate the powermeter does it happen every so often that it gives an error and the red led flashes?
It happens to me occasionally with two models both with the latest fw.

I've never had that happen with mine

firmware version?

Fully up to date FW

[Maxxlefty]

the manual says:


"If the LED blinks red, perform zero offset calibration again."

[ms6073]

if you know you have 60 40 balance, what do you do with this information?

I have a friend who suffered a severe injury from playing basketball during his grade school years which required a hip-replacement at age 18 and recently had the replacement, replaced. I am pretty sure his L/R balance is probably in a similar range, yet even with asymetic length crank arms, oval rings, and cleat shims, there is not much else to be done. So from my perspective, attempting to compensate/correct normal/minimal imbalances, really seems an exercise in futility, but when we start talking 60/40, then I would think that is more of a bio-mechanical/medical issue that is best addressed through appropriate diagnostics from medical professionals.

[1sanglier]

Same reason for me.

[ipenguinking]

the manual says:


"If the LED blinks red, perform zero offset calibration again."

My unit started showing this after firmware update several months ago. It did not have this issue while on the original firmware during the first 12-14 months. (always finish zero-offset successfully with green LED) I'm not sure what Shimano did.

[ms6073]

the manual says:
"If the LED blinks red, perform zero offset calibration again."

I'm not sure what Shimano did.

I saw this one time after calibrating with the bike leaning at an angle against a wall at the house. Stood the bike up straight and repeated with no issues. My take is that Shimano tweaked the parameters for the calibration such that it returns the error if one of the conditions is not met.

[Maxxlefty]

the manual says:
"If the LED blinks red, perform zero offset calibration again."

I'm not sure what Shimano did.

I saw this one time after calibrating with the bike leaning at an angle against a wall at the house. Stood the bike up straight and repeated with no issues. My take is that Shimano tweaked the parameters for the calibration such that it returns the error if one of the conditions is not met.

I understand how the powermeter thinks. With the old firmware the calibration returned a number on the garmin 5050 but if this number was different from 5050 the led flashed green. Now with the new firmware, if the number is different, the Garmin always displays 5050 but the calibration failed and the red LED flashes. To get this feedback, I connected the powermeter to the smartphone and calibrated from there. In the cases of red LEDs, a different number appears on the smartphone.

In conclusion, the calibration mode has changed. Before, even in the event of an error, the LED was always green and one did not notice it except by reading the data on the garmin.