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Your cart is empty.Used to pace attacks up the Alpe D’Huez in the Tour de France and to hammer on the Queen K during the Ironman World Championships, the PRECISION Powermeter delivers accuracy and reliability when you need it most. Through our patented 3D Strain Gauge technology, you can be assured that the data you depend on will lead you to your own Yellow Jersey. Packaged into a durable lightweight design and compatible with ANT+ and Bluetooth Smart headunits, PRECISION will help you train harder and smarter. Features: Accuracy: +/- 1% Battery Type: CR2032 Coin Cell Battery Life: Up to 800hrs Waterproof Rating: IPx7 Cadence Range: 30 - 170RPM Power Range: 0 - 4,000W Height: 5.5mm Weight: 9g Operating Temperature: 0 - 50°C Communication Protocols ANT+, Bluetooth
Kofi
Reviewed in the United States on May 25, 2024
It was straightforward, easy, and uneventful to replace the NDS (Non-Drive-Side) arm on my Shimano 105 5800 crank with this. There is only a very slight inconsequential difference in appearance between the Shimano 5800 arm and this (which tells you how well-made it looks). It was easily detected by a Garmin 520 cycling computer - be sure to select the entry for single-side power meter, don’t select the ‘balance’ options but rather the menu options after ‘power’. I also very much like the fact that it is compatible with the Apple Find My app so that the location of my bike can now be tracked.if it’s ever stolen. For the money, very highly recommended.
Jodi Girl FL
Reviewed in the United States on February 24, 2024
If you want to get faster, you need to train by raising the intensity. The harder you ride, the faster you will get. Before power meters, it was by perception. We use RPE now to scale this from 1-10, but with Rate of Perceived Exertion, it's relative to how hard you THINK you are working. And it works better with experienced athletes.With power meters, the guesswork is taken out, and you get exact metrics. And they used to be - expensive. Over the years we have installed plenty in the bicycle shop, but I never bothered with using them myself. I stuck to RPE and when I wanted to train muscular endurance, I headed for the hills, did punishing intervals, and watched my time in my heart rate zones.Which is not super accurate. After using this device from 4iiii, I have to wonder how much better I would have done if I had used a power meter. It gives you the cold hard facts and points out your defects, and those are what you need to train if you want to win.This one from 4iiii is super easy to install - it's all contained in the left crank and pairs up quickly to either the BLUETOOTH App on your cell phone, or in my case my GARMIN 910XT. You get plenty of data to analyze, and I mounted a spare GARMIN on my MADONE to get real-time feedback while I ride. After using this for a month, I changed my training, focused more on various things in my pedal stroke and how I trained for muscular endurance, and have seen both my power output and speed increase. So it works!.A big plus with this one is that it has three strain gauges, increasing the accuracy, and is totally waterproof - I rode it in the rain, with no issues - and if you are concerned about weight(snicker) don't be - it's only 10 grams heavier than a DURA ACE 7800 left crank. The price is really good compared with the complete crankset power meter pricess, and the accuracy is at the same level. What will help you if you purchase this - and you should if you are serious about racing and winning - is to get a good book that describes the ins and outs of using a power meter. I'd recommend "The Power Meter Handbook" by Joe Friel, available on AMAZON. The same author of "The Training Bibles", Joe has a unique ability to render complex subjects easy to understand and has trained many average as well as world-class athletes and made them fitter and faster.OVERALL - It also works with APPLE FIND MY, and comes with a 3-year warranty. But the best thing - it makes you faster - quickly. KEEPER for sure!
Kevin Compton
Reviewed in Spain on October 15, 2024
Highly recommended. Delivered quickly and 10 mins to install. Works perfectly.
Run26
Reviewed in the United States on January 3, 2024
[Note: I got this for free through the Amazon Vine program in exchange for my honest review.] The item available was a Shimano 105 labelled meter on a 172.5 mm crank; my bike has 175 mm Shimano Ultegra cranks, so this isn't an exact match, but I did want to try it out. The 105 non-drive (left) side power meter crank arm fit exactly onto my Ultegra spindle since both use the Hollowtech components. I'm not overly concerned about the 2.5 mm difference in crank arm lengths for the time being (I have bar tape thicker than that!) because it's a pretty negligible difference, especially given that most of my rides are only in the 30 - 50 mile range; it's not like I'm pedaling all day. Installation was a breeze, the hardest part was getting my pedal off the old crank arm so I could remount it on the power meter. I did need to buy a special tool to remove the dust cap over the spindle, but that was only about a $6 purchase on Amazon. I've never removed the crank arms before but a short YouTube video showed me the way; besides the dust cap tool all I needed were a couple of Allen wrenches and a dab of grease. The power meter came with a battery installed and was ready to go right away. I paired it to my Hammerhead Karoo2 bike computer which was a simple process, and it took no more than a few seconds to perform a zero calibration on the Karoo2. Now I have the power output continuously displayed on my Karoo2 along with cadence, HR, speed, and distance, and saved in a file that I can upload to other apps (i.e., Strava, RWGPS, etc.). I can't speak for the accuracy of the device, but I will say that in a short trial it seemed equivalent to the calculated power readings I get on my indoor Wahoo Kickr smart trainer. I'm still in the early stages of playing around with this power meter until I can get outdoors more in the spring, but I'm planning to use it to be more mindful of consistency during training efforts on the bike. All in all, 4iiii is a quality maker of power meters and I would rate this as an excellent value for the listed price. If all continues to go well, I'll purchase the correct length meter in a matching Ultegra unit and pass this one along to a clubmate.
Vince of the Midwest
Reviewed in the United States on December 15, 2023
What it is: Left side single power meter for Shimano 105 7000 series crank sets. Packaged eco-friendly, with a QR code to acquire instructions. Styled to replace and match your left crank arm with Shimano graphics and matte + gloss finish. Includes waterproof and gasketed battery compartment/transmitter and includes a pre-installed cr2032 battery. Depending on what GPS it is paired to, it will display power (Watts), cadence, and related data. Phone App required to update firmware, and the app requires account registration with 4iiii.Why I like it: As an avid cyclist, I use data from my bike gps to gauge fitness and improve performance. I paired a speed sensor to improve accuracy when riding in the woods, a heart rate monitor, and now a power meter.Pro Tip:While this particular meter is designed and styled for Shimano 105 7000 series, it is compatible with actually compatible Hollowtech II splined crank sets. My gravel bike has a Shimano 5800 series 105 crank set, and this power meter crank was a direct swap. It weighs just 9g more than the Shimano 7000 OEM crank it replaces.Once installed, it wakes up after spinning the crank a few times. It paired easily with my Lezyne GPS unit. I then specified the crank length, and added the power and cadence windows to my display screen. I then placed the pedal cranks at 12 and 6 o’clock position, and calibrated it. On the GPS screen and phone app, you can check battery life as well. I did a winter rude, and the unit tracked perfectly and accurately—just make sure it is calibrated every so often, especially after battery replacement or firmware updates. The phone app is required to check and install firmware updates, and works well for connecting the power meter with phone based fitness apps. The only downside is I have to create an account with 4iiii to use the power meter management functions. Overall, it is a substantial investment, and a quality power meter backed with a 3 year manufacturer’s warranty.
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