Shimano-r9100_Dura-Ace_FC-R9100-P_power-meter-crankset_overall

We were first really introduced to the new integrated power meter version of Shimano’s new R9100 Dura-Ace crankset just a few weeks back at the introduction of the new groupset. But at the time the power meter itself seemed pretty hard to come by, and details were still few and far between. All we really had seen were studio photos from Shimano, but now we have had a chance to get on a power meter-equipped bike and we have a bit more real info. Take a closer look at what makes the R9100-P tick, and when you might be able to get one, after the break…

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Shimano didn’t mention it to us, but the power meter does require a frame magnet for cadence updating, which we’re hoping will get a more elegant solution. The sending unit includes a single LED that signals when it first wakes up, and when pairing. It also gets a single button that provides a one step zero reset from the transmitted body for easy everyday functionality.

Shimano-r9100_Dura-Ace_FC-R9100-P_power-meter-crankset_driveside-sensors-back Shimano-r9100_Dura-Ace_FC-R9100-P_power-meter-crankset_driveside-sensors-back-detail

The tech that makes them work looks very similar to that of Pioneer, even though they were not developed as partnership. Shimano also reassure us that based on the location of the sensors on the back of the driveside crank, it offers full compatibility with all of their standard and compact rings, and chainrings can be easily swapped without affecting the performance of the power meter.

While the standard crank will offer more chainring sizing options, the power meter version will come standard with either 50/34, 52/36, or 53/39 options.

Shimano-r9100_Dura-Ace_FC-R9100-P_power-meter-crankset_non-driveside

Both sides of the crank are connected by a fixed wires to the internal spindle rechargeable battery for reliability, and a proprietary snap-on magnetic charging cable delivers power without ever having to expose cable connectors. Shimano was pretty set on making it totally waterproof in pretty much any conditions (and that apparently was most pushed to the extreme by how some pro mechanics wash the bikes) so you don’t have to open anything to keep it running trouble-free.

Shimano-r9100_Dura-Ace_FC-R9100-P_power-meter-crankset_non-driveside-sensor Shimano-r9100_Dura-Ace_FC-R9100-P_power-meter-crankset_non-driveside-clearance

As we saw earlier the wide boxy shape of the new Dura-Ace crankset was the result of an analysis of the stresses in the actual arms themselves, and not a result of space needed to fit strain gauges or communication tech inside.  But all of that real estate did give Shimano a lot of space behind which they could hide the sensors for a clean overall look. And in fact the mostly external sensors are then just adhered along the wide flat inner sides of the arms.

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The cranks talk through both Bluetooth & ANT+to your computer of choice. We rode one set up with a Garmin Edge head unit and displaying the core, simple power metrics, but plenty more detail is of course possible.

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The functioning version we saw is still pre-production. That means that even though everything looked nice and finished and worked without any issues, it was missing that last touch of Dura-Ace branding that will grace the final version.

Even the pros aren’t really on the new power meter cranks as they are quite available in any numbers yet. But Shimano tells us that they are on track to deliver to their sponsored pro teams to be ready for the January 1 start of a new year, and what that means for us mortals is that it will coming our way too. The expect that by the end of February it will be available to all.

DuraAce.com

19 COMMENTS

  1. I’m assuming the crank arm pod is pre-attached? Did you measure how much it sticks out from the inside of the arm? My Emonda frame doesn’t have much clearance, but I have to assume it’s been designed to fit most newer bikes’ tight chainstay clearances…

    I’ll probably still buy this, but man this crank is a big step back in aesthetics… And the frame magnet?!

  2. As someone who has worked with Powermeters for years, I can say that a magnet is the best way to get precise cadence. For sure it can be a complete pain to get a magnet placed correctly on newer frames… but the reason why a magnet is the best option is this: Your Powermeter needs EXACT cadence to calculate power. Your head-unit is showing, for example, 85rpm. However, to accurately calculate power (remember that these systems are striving for a +/-1% accuracy) the system needs to understand the EXACT angular velocity–like 85.345683rpm or 84.937594rpm. At the end of the day, the magnet gives a failsafe way to give the exact start and finish of a revolution. Additionally, magnet placement is not all that hard. I have seen so much mis-information, but the take-away is this: if your Powermeter is registering cadence, the magnet is positioned correctly. If you have tight frame clearance issues, there are literally hundreds of very small and very powerful magnets available for purchase. Simply attach the magnet to your frame with a drop of super-glue and surround the edges of the magnet with a small bead of silicone. This method will ensure that the magnet will stay put throughout extreme weather, cleaning, solvents, lubricants, etc. I have done this on dozens of bikes and cannot remember a magnet coming off a frame.

    • What?

      If you assume half your +/- 1% allowable error error comes from cadence, and half your error comes from strain meters, you only need cadence to be accurate +/- 0.5%. At 85rpm, that’s ~84.6rpm to ~85.4rpm. Tenths are more than enough. You don’t need millionths, and if you needed that kind of precision, then you should probably be sampling more than once a revolution at 85rpm.

      Torque x RPM = Watts. If your given torque at 85rpm gives 100.0w, 85.4rpm will give ~100.5w and 84.6rpm will give ~99.5w.

  3. Just give me one in a DA9000 crankset and I’m sold. Throw together a decent computer with GPS and I’m kissing Garmin good bye. I’m simply tired of their half baked products. Shimano save us!

  4. Been running a DA9000 Stages for 3 years and smashed it thru heaps of river crossings during epic rides in Thailand/USA & Australia and its still going strong. I can afford any power meter but I just can’t see the reason I would want to add more complex product to my bike for ZERO benefit.

    • @Durianrider, out of curiousity, have you ever measured your left/right power balance at different output levels with a two legged device? For those with a disparity, particularly one that varies with output, it seems like a valid reason to consider a more complex product. Of course, your vegan diet might be keeping you perfectly balanced, ;-).

      • Dude, nobody knows what the heck to do with left/right power information. Seriously. What are you supposed to do extra squats on one leg? Try to think about pedaling harder with the other one? If Team Sky was fine with Stages power meters last year, they are good enough for everybody else!

        • Actually not true. I broke my hip last year and it was a very good way to monitor the recovery, and also note how the two legs performed in differing situations. I’ve just broken my other leg and have now a pattern and programme I can follow for recovery.

  5. Is the driveside crankarm fatter than the other side, or is that an optical illusion? Just can’t see this crank on a slim-tubed frame…

  6. Well, all in all after seeing and trying out the new R9100 Dura Ace at EuroBike I have to say:

    THIS is the most underwhelming Shimano release I can remember! The whole groupset looks even WORSE in real life than in the pictures and apart form the rim brakes, which ouperform basically anything I have ever tried, it is a step backwards. The shadow + long-cage is not only a departure from elegant aesthetics, it also is a departure from the Dura Ace shifting we know:

    No more silent is golden operation.
    The quick shifts are supported by a metallic click and clank, very much like with a mechanic Campagnolo Record.

    Also, the front derailleur on the test bike provided by Shimano was a complete nuisance, delievering slow inaccurate shifts labeit the tension being pretty high… it performed really badly.

    In my opinion Shimano has moved in the very wrong direction by making their road groups more like their MTB groups.

    SRAM on the other hand is clearly moving along a very different path, seperating the two lines cearly which results in superior performance, much better looks and unrivaled innovation (eTAP vs Di2, 12×1 Eagle vs XTR)… and concerning the power meter options: Their are tons of Power Meters which semlessly integrate with SRAM Direct Mount cranks. You can get Quarq, SRM, Power2Max (etc.) to match your SRAM Red cranks, they all work well and you get the choice between maximum accuracy and longevity (SRM) or something more suited to an every day riders budget (Power2Max, Quarq)…

  7. Regarding cadence magnets, I have used these for years on my Quarq power meters. Until one day….. a stone got between the crank and bike frame, while I was racing. I couldn’t stop. The stone ripped the magnet off (fixed with epoxy) and then the two of them rattled around, somehow, for the rest of the ride. When I checked, both the frame and the plastic surface of the quarq were damaged. On another occasion, the magnet came off (during a race) and ended up in the cassette. I checked why the (quarq) magnet had come off – it had rusted from the inside. I’d rather not have any more cadence magnets, thank you.

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