Shimano R9100P Review

 

In this detailed Shimano R9100P Review, we will look at Shimano’s only own-branded power meter to date. Let’s start off with a summary, which might be enough for most people, and then I’ll follow that immediately below with all the supporting detail for those who want it as well as a link to a separate post on data accuracy.

Shimano R9100P Background & Future

The R9100P started shipping to real customers at the back end of 2017 and, since then, has changed very little in terms of firmware features. Then, and now, the R9100P’s spec was/is very decent with good battery life and an acceptable, claimed accuracy level. It hits the key buttons that people want in terms of the kind of data it transmits (L/R+cadence) and the transmission protocols it uses ie BLE and ANT+. It doesn’t represent, to me, a notable increase in weight and it supports everything I would want from a Dura-Ace crank in that it ‘supports’ Shimano’s normal chainrings, BB and forged metal construction (Hollowtech II).

But really this product is Shimano’s stepping stone to their power meters of the future and they had to start somewhere. The end game sees companies like Shimano supplying a new power meter on most new ‘performance bikes’, so even the future equivalent of a Shimano 105 groupset will probably, in a few years’ time, come pre-bundled with a power meter or, if not, there will be only a small premium for you to pay to upgrade to one.

The aftermarket for the likes of Favero’s Assioma pedals (which I love) will become an increasingly tricky place for them in which to keep a foothold.

But you’re perhaps thinking of buying one NOW, so let’s return to the present. Well, let’s go back a few months to when I first put this onto my 2020 bike.

Shimano R9100P – Contents & Installation

I find buying a crankset a bit daunting.

Will it fit the width and diameter of the bottom bracket bearing that’s in your bike now? If it won’t you can get a new bottom bracket but to cut short a somewhat turgid discussion on bearings, I’ve included the official R9100P specifications, below, where you can see, for example, it supports the relatively standard, Shimano BB-R9100 (I have ROTOR bearings).

Ask & support your Local Bike Shop.

The box comes with a few more pieces than you might expect, they’re all needed. There are a few special bits to help with the installation, a cable for charging and some other bits to pretty-up the finished installation.

 

Shimano R9100P – Design Elements

I mean, it’s a Dura-Ace crankset with some bits stuck on right?

At first glance of the image above, that statement seems true. You get the two ‘pods’ on the inner face of each crank. But consider then how they get their electrical power.

As you can see from the following diagram, the battery is in the axle and linked to both pods as well as to the external charging port.

The advantage to Shimano of this ‘integrated’ design is that their sensor pods can be smaller than, say, the likes of 4iiii or Stages who also add their units to Dura-Ace cranks. Maybe the small pods look better? not that you ever really see them.

But then to get the power from the battery to the left-side sensor requires the following fiddly-looking connector. Although in reality you simply push it in.

It sounds & looks worse than the reality, once the cap is placed over it you’d never know it was there.

Then we come to the charging port itself at the top of the spider on the following image. You can obviously see this but I’d say it’s sweetly integrated in an unobtrusive manner into the design.

The whole cap pivots off to reveal the charging port. Sounds simple? No. I opened it before putting it on my bike and fiddled around a bit. Finally, a few weeks later, it was all installed and ready to go but I hadn’t charged the PM up. So I had to open the port with the bike hanging off a wall mount. It wouldn’t open and I’d forgotten (for certain) which way it opened. Obviously, I could have forced it but then I remembered its pivot was a plastic tether of some sort. I had to refer to the manual to figure out which way to open it! Just in case. Then I attacked it with a screwdriver once I knew for certain I wasn’t going to break it 😉

It charged up and that should do me for a few months. By which time I will have forgotten which way it opens again #Sigh.

You can also see a tiny little button on the image above. You press that for ‘blue light mode’ aka pairing to the E-Tube app after the installation or for a forced calibration independently of a headset.

Installation

The installation is straightforward and with the right tools you should be able to get it up and running in between 10 and 60 minutes – I’m nearer a 60- than 10-person for new jobs like this ;-). I’m expecting to switch this over to other bikes periodically in the future which will have the same BB and exact same gearing, I’m hoping for 10 minutes for such subsequent installs.

The one thing that stands out is that the cadence info comes from a magnet that you have to fasten to your frame. Most new PMs now calculate this internally from their accelerometer, however, this is only going to cause you a problem if you plan on moving it to other bikes. Which I might.

Shimano R9100P –  Connectivity to Sensors & Apps

You pair by BLE (Bluetooth Smart) to your smartphone for the device maintenance and then by ANT+ to multiple simultaneous devices such as your watch or head unit. You can also pair to one BLE watch, head unit or app eg Zwift.

Shimano R9100P – E-tube App

The Shimano E-Tube app is also used if you have to manage your Di2 setup and the functionality in the E-tube app that’s solely designed for the R9100P is limited but sufficient. There are some images from the iOS and Android apps below – both apps seem identical to me. In summary, the app lets you

• See battery status
• Check firmware version
• Update firmware
• Enable ANT+ and/or BLE connection from the R9100P. BLE can be handy for Zwifters, others most people might get a few more hours of battery life by disabling it
• Perform a zero offset calibration
• View but not save power and cadence

Over several days, unusually, I found pairing to the Android app worked better than iOS.

Note: E-tube app has since been updated. It looks prettier but is still flaky at pairing. Don’t forget to press the button first 😉

Firmware Update History

Update to the latest version of the firmware for the most accurate results.

Here is the full version history ( here). The version I used was 4.1.7 and I performed the update from 4.0.7, using the Android 3.4.3 version of E-Tube.

Sensor Pairing & Sensor Data Types

Pairing is like any other sensor and is, pretty much, pair and forget. After pairing it just works, spinning the cranks should be enough to wake the PM up, if not briefly press the button once.

I would prefer ANT+ over BLE any day and with the Shimano R9100P, this gives you extra geekery with Pedal Smoothness (PS) and Torque Effectiveness (TE) metrics. Here’s what is transmitted

• Power
• Left/right power balance
• Cadence
• Battery level information
• Pedal smoothness (ANT+ only)
• Torque effectiveness (ANT+ only)

Only 1 BLE connection is supported, so try to simultaneously pair to Zwift and your Polar Vantage V and only one of those will work.

Shimano R9100P – LEDs

• Blue – unit is charging
• Blue turns off – unit is 100% charged
• Green – battery level is over 16% (see the app or head unit metrics for an estimation of the level)
• Red – 3-15% charge
• Flashing Red – 1-2% charge
• Press and hold the button to get a Blue light to start a manual zero offset when the flashing stops…it’s done. there is no LED indication of fail or pass of the calibration.

SHIMANO R9100P – Technical Headlines

The specifications are in the next section. Much of that, to me, is too techy so here are the key aspects of the R9100P as I see them

SHIMANO R9100P – SPECIFICATIONS

These are the Shimano R9100P specifications according to Shimano

MODEL NO	Shimano Dura-Ace FC R9100-P Power Meter Hollowtech II Crankset
SERIES	DURA-ACE R9100 Series
Colour	Series colour
Average weight	power version adds about 75g additional weight to Dura-Ace cranks 696 g (53-39T), 695 g (52-36T), 685 g (50-34T) regular Dura-Ace crankset weight 621g (53-39T), 609g (50-34T)

SHIMANO R9100P – Daily Use

Just like any other power meter, you perform a dismounted, daily calibration with the bike and the cranks both vertical.

5050 is the correct response for a watch/computer calibration, maybe that means 50 left and 50 right…IDK. Otherwise, with the Shimano app, you get a tick when calibration is passed whereas, with the button-press calibration directly on the R9100P itself, there is no feedback of pass/fail just feedback that the calibration has ended when the light stops flashing blue.

The calibration seems to always work and the R9100P is a ‘just works’ device. There are zero obvious issues with calibration. If it’s the only power meter on your bike you’d be oblivious to the correctness of the data. If you’d ridden other correct power meters before then, again, you’d be oblivious to the correctness of the data even if you are showing 3s smoothed power.

Visually on the head unit, the reported headline power levels seem right and the cadence seems right when I compare to other PMs

I have a pedalling imbalance, something like 52:48 (L: R), which I am actively trying to correct with strength and flexibility work in the gym. Consequently, I am not 100% sure of what I am seeing with the power balance, superficially I would say that the right side is slightly under-reporting my imbalance but, as the total power seems fine, then I’m only going to be able to explain that AFTER the workout looking at accuracy…and that’s in the next section.

BTW: I’m not entirely sure that ANY of the fancier metrics PS/TE and any kind of balance are accurate on ANY device out there. But that’s another story entirely. And yet another story would question whether it mattered in any case.

SHIMANO R9100P – on Pro Teams

The following teams are ALL sponsored by Shimano to use the R9100P in 2020: Astana Pro Team, BORA Hansgrohe, CCC Team, Deceuninck, Equipe Cycliste Groupama-FDJ, Mitchelton-SCOTT, Team Bahrain McLaren, Team INEOS, Team Jumbo Visma and Team Sunweb.

OK, they are paid-for relationships but the pros either get some use out of the R9100P or don’t look at/analyse the figures it produces. I would imagine it’s the former.

SHIMANO R9100P – Accuracy Testing

For the purposes of this Shimano R9100P Review, I can only test 3 simultaneous devices, indoors like this: Kickr 2017 + Wahoo cadence sensor; Shimano R9100P; Assioma Duo. When I go outdoors I only have 2 devices so I don’t know which one is right.

I’ve got a Stages Gen3 Dual and Garmin Vector dual as well. But the Vectors are not as accurate as the Assioma so I never use them and I’m not going to waste my time using them for the purposes of these tests…so that’s that. Sorry! I’ve got some ‘peripheral’ PMs too but they aren’t going to help with comparisons and, as you can guess, I need a PowerTap G3 to compare 3 devices outdoors but haven’t got one. I’ll later and separately post the Stages Gen3 figures compared to the Kickr/Assioma and that might then let me infer things about the R9100P.

I’ve done the GPLAMA test and those files are available for anyone that cares to use them. For other workouts, I’ll show some of the interesting stats of those rides.

Summary: Judging by variances to other devices it seems reasonable for me to say that the R9100P at least meets the average accuracy claim by Shimano. The R9100P, if anything, tends to slightly overestimate total average power and might even underestimate my right-side power.

 

Longterm Accuracy Update: Below is the repeated LLAMA test. Nothing to see here as all devices nicely match. If you can spot the supposed LR problem then you’re better than me! I’ve used the R9100P as my main power meter for the last 6 months mainly because I like the Shimano cleats and got fed up with the LOOK cleats on the ASSIOMA! and, of course, the data is perfectly actionable when it comes to accuracy. I’ve done thousands of miles with the R9100P and…no problems except once when my chain came off taking the magnet with it. No magnet = No cadence = No power.

 

Here are details of the original accuracy tests from 2021 in a separate post

Shimano R9100P Accuracy

What Next?

I doubt that the Shimano R9100P will receive any more significant firmware updates and I doubt the current design will be made into an Ultegra version.

Instead, a Dura-Ace R9200P could come Q1/Q2.2021. But make no mistake, it WILL come.

More Thoughts & A Summary

I like the regular R9100 cranks, so adding on a power meter makes sense to me in the scenario of either an accident-induced replacement crankset or a Dura-Ace upgrade treat for your only bike. And if you and your buddies have Shimano groupsets then you just know that you all really want to have Dura-Ace emblazoned all over your bits…so to speak. (I’m describing myself here…I’m shallow too 😉 )

Nevertheless, I DO prefer my Assioma pedals for a lot of reasons EXCEPT those freakin’ LOOK cleats on the ASSIOMA have really started to hack me off. I’ve completed just a couple of rides with ONLY the R9100P and my old Ultegra pedals (ie no other PM present), indeed I’ve not ridden with Ultegra pedals much for a few years now but I tell you on those few occasions of blissful Utegra pedalling, it was an absolute joy to get my feet back in my stinky, old shoes with the Shimano cleats and never dread the thoughts on unclipping/re-clipping at junctions. You probably didn’t want to hear that ‘trivial’ comment when thinking of buying a $/£/Eu1000 power meter/crankset…but after a while, it’s precisely those things that are important ie the cycling things you have to do again and again and again and again.

Almost everyone that uses a half-decent power meter will tell you that, once the initial excitement wore off, they NEVER look at any of the fancier metrics that the power meters broadcast. However, if you are a Garmin/Wahoo Zwifter without an ANT+ dongle then you just know that you will want that BLE channel as well as the ANT+ one. The same argument applies if you use any of the other popular trainer apps. So, all is good in this respect but, of course, most competing power meters these days will give you ANT+ and BLE too.

Finally the accuracy. You’ve perhaps not clicked through to see the details of what I found but if you look at those comparison charts they were usually pretty much identical looking at a high level. If you’re only using one power meter or two+ of the same power meter then the Shimano R9100P is going to be perfectly fine – even with 3s smoothing on your headset, you wouldn’t be able to tell the difference to another PM. The bottom line was that even though I have a balance issue I don’t look much at the balance data – so I’m only interested in the headline power figure.

Summary: In the end, they’re consistent enough for me; they’re pretty, with the right branding for me and I get to use my preferred Shimano cleats.

Buy Shimano R9100P – Price, Availability & Discounts

If you are looking to buy a Shimano R9100P then the RRP is £1499.99 but even at the time of publishing, you can buy these significantly discounted for £1088.99 or Tredz for £1399 – it varies…check them all out.

In the USA, Competitive Cyclist has these from $1376.00 or check out Power Meter City (USA) for the new R9200p

Prices will vary and the blue banner below gives you a choice of retailers to help you shop around in your local country.