Shimano's New Power Meters, 2nd Gen Dura-Ace R9200 and Ultegra R8100

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anyone have a pic of the backside of the 9200 crankset without the PM by chance? Can’t seem to find one in any of the publications

reading that was an encouraging.

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My main bike is equipped with FC-R9100-P and I´m really happy with it because it just works without any problems.

Thought about buying the new ultegra powermeter for my winter bike - but after seeing the price tag and reading dcrainmakers first comparison with FC-R9100-P (see below) I directly ordered an second FC-R9100-P because I don´t see why I should pay more for no real advantages:

The differences:

  • Changed crank arm materials
  • Changed crank arm manufacturing process
  • Battery cap is now replaceable
  • Battery is on side of spider rather than top
  • Battery connector cable changed to match Di2 rear derailleur charger cable (so you only need one cable)

What’s stayed the same:

  • 300 hour battery life same as before.
  • Internal rechargeable battery is identical as before
  • Weight remains of the same (though, the new crank arms are about ~60g heavier than before, depending on exact chainrings on them)
  • Claimed accuracy of +/- 2% remains
  • ANT+ & Bluetooth Smart power broadcasting (total power/power balance/cadence)
  • Magnet still required on frame for determining cadence/position of crankarm
  • Active temp compensation same as before
  • The strain gauges are placed in the same spot as previous as well.
  • Still a dual-sided system (both left and right crank arms have sensors on them)

I’m not sure if you read dcrainmaker’s post thoroughly, but this excerpt should give you pause:

I’m cautiously optimistic about accuracy potential on the new 2nd gen Shimano power meter. At no point during our conversation did Shimano shy away from the challenges and limitations they had trying to make the 1st gen unit ‘work’ on a crank arm that wasn’t designed for it.

In short, there are problems not so much with the power meter, but rather in how the drive side of R8000/91000 cranks flex when force is applied is not consistent, which makes crank based PM’s (of any brand) problematic on Shimano cranks.

I’m not sure that this weakness was known when Ray published his original 9100-P review in 2018, but thanks to the work of @gplama, this issue is known now.

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I think the main difference is that although the claimed accuracy remains 2% the new version might actually achieve it in real life more often.

I have no reason to doubt that you have a good 9100-P - but they certainly aren’t all like that.

Yes I read that. I read his old review of FC-R9100-P too.

I tried powermeters from Stages and from Garmin which had so so so many problems and where eating coin cells which where drained because of the hardware issues these powermeters had. Then I changed to the shimano PM (despite of the DCR review) and was just really happy with it. Never had any issues with it and for me it´s perfectly accurate enough.

Is an accuracy gain of +/- 0,5 to 1,0% as important as some hundred euros for me? Nope.

Do the “problems” Ray writes about affect my training success in any way? Nope.

No problem. Just wanted to make sure you were making an informed decision, as Ray’s review and the table of differences wasn’t explicit as to the issue (which to be fair was the crank, rather than the PM).

Here’s to spending the hundred euros on replacing the tires worn out from all the riding you are about to do. :+1: :slightly_smiling_face:

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YEEHA! Totally agree! Let´s ride! :+1:

The initial thing that is depressing is the MSRP that’s been quoted:

  • Ultegra $1,100 / $1,200 USD range
  • Dura Ace $1,400 USD range

The question will be: what is the incremental price if added at the time of purchase on a new bike?