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The 4iiii Precision 3 Power Meter is accurate and easy to live with. A longer battery life than previous models means fewer battery swaps, and the consistent data makes it easy to train with on a daily basis. For UK users this is also the fastest way to get your existing crank converted to power measuring. There's a lot to love.
While a lot is made of a power meter's accuracy compared with other power meters, for many riders who can only afford and therefore just use one power meter, the main thing is getting data that yes, is accurate, but getting it consistently, day after day, with no dropouts or weird spikes.
In terms of this consistency, the 4iiii Precision 3 has been perfect, and after a firmware update to this pre-production sample that I've been testing for a few months, things have been plain sailing. The device wakes up and connects quickly to my bike computer, the data delivered has been reliable, and there have been no bugs to cause frustration.
Compared with the Precision 2, 4iiii has increased the length of the power meter's plastic body, but the height has been reduced to just 5.5mm. Clearance has never been an issue with my frames, but I know that some Canyon frames, amongst others, have been unable to accept a 4iiii Precision power meter. The slight reduction in size could help here.
The other big change is that the Precision 3 comes with a claimed 800-hour battery life. That could mean a vast reduction in the number of times you need to change the battery; having only ridden for 70 hours so far in 2022 (not all on the 4iiii), I'm nowhere near needing to change it. Even if you were training like a pro, logging 30-hour endurance weeks, you'd still be fine for months.
I can't verify those battery life claims, and it will likely depend a fair bit on your riding conditions as batteries don't like cold weather, so I can't give an indication of how accurate this claim is.
I got the Precision 3 well ahead of the unit's launch and that meant two things. Firstly, I wasn't able to get a Shimano Ultegra crank as there was no 170mm size. Instead, I was sent the 105 model, althoug that really doesn't bother me.
Secondly, I was using the Precision 3 before all of the creases had been ironed out. My first few weeks on this power meter presented a few issues. In terms of accuracy, this meant that I was seeing numbers that I've always wanted to see – unfortunately, my max sprint power isn't 1,309 watts, and in late December there is no way that I can put out 323W for 11mins 20secs, especially having just recovered from Covid and spent the previous week doing Christmas-level drinking and eating. For context, the sprint power was about 200W high and the longer effort would typically be around 300W. Those are significant differences and a quick ride on the indoor trainer confirmed that the crank was reading high.
Thankfully, after a few messages to 4iiii and a little update on the app, the numbers returned to their depressingly normal-looking values. Covid doesn't give you superpowers, as it happens.
Since then, the numbers have been reliable and consistent, which is just what is needed for regular training. I haven't seen any dropouts, which is very nice when you're riding on Zwift as I don't want to be dropping back through the group for any other reason than my shoddy fitness.
Installation is super simple, and if you're running a few bikes with Shimano cranks then this is a pretty easy one for swapping between them. Yes, it's still not as simple as something like the Garmin Rally pedals, but it certainly isn't the hardest job.
The Precision 3 is rated as IPX7 waterproof and really, this just means you'll be safe to wash your bike and ride in the rain. I've had zero water ingress issues with numerous older Precision power meters, and with the battery door remaining the same I don't see there being any problems here.
The 4iiii app continues to be simple and easy to use, and since the firmware update I did after the week of weird data, there have been no updates to do.
Rivals come from the likes of InPeak's 105 crank at £290 and Stages with the G3 105 R7000 crank coming in at £325. All three are brilliant ways of getting power on your bike for a relatively palatable price, but 4iiii does have a slight advantage for UK customers. Its factory installation process, which takes your existing left crank and makes it a power meter, is done in the UK. The cost is the same as the Stages factory install at £299.99, but 4iiii will do the installation in the UK, whereas a Stages crank has to go back to the main factory in the US. The difference is roughly a one-week turnaround compared with four to six weeks without your crank.
All in, the 4iiii Precision 3 brings an impressive boost to battery life in a package that is a little bit thinner and just as good for the everyday cyclist as the previous model. The data is accurate and the consistency of the unit makes it easy to live with. You can have your existing crank converted for a very reasonable price in a short space of time.
Still accurate and still a brilliant way to add power measuring to your bike for a sensible amount of money
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road.cc test report
Make and model: 4iiii Precision 3 Power Meter Shimano 105 R7000
Size tested: 170mm
Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
4iiii says: "Used by the best cyclists in the world, the PRECISION 3 Powermeter builds on the accuracy, reliability and durability that 4iiii Powermeters are known for. The PRECISION 3 Powermeter boasts 8x more battery life, delivering up to 800 hours of ride time. The new design is 40% thinner to ensure compatibility with more bike frames than ever before."
Tell us some more about the technical aspects of the product?
Battery Life: 800 hours
Waterproof rating: IXP7
Cadence range: 30-170rpm
Power range: 0-4000 watts
ANT+ and Bluetooth
Around the same price as Stages and InPeak offerings – still one of the cheapest ways to get power on your bike.
Tell us how the product performed overall when used for its designed purpose
After this pre-production unit had been updated, there were no issues with power accuracy or dropouts, so it performed consistently. That's just what you need for day-to-day training.
Tell us what you particularly liked about the product
The easy-to-live-with nature of the Precision 3 is great. It connects quickly and then delivers accurate data consistently.
Tell us what you particularly disliked about the product
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
The Stages Cycling Shimano 105 R7000 Power Meter is the same price while the InPeak 105 R7000 is a bit cheaper at £290.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
One of the cheapest ways to get power measuring on your bikes, and with its accuracy and consistency, it is one of the best. The increased battery life is a big plus and the thinner design should help it to fit more frames. It's excellent.
About the tester
I usually ride: Specialized S-Works Tarmac SL7 My best bike is:
I've been riding for: Under 5 years I ride: Most days I would class myself as: Expert
I regularly do the following types of riding: road racing, time trialling, cyclo cross, commuting, club rides, general fitness riding, I specialise in the Cafe Ride!
Son of a Marathon runner, Nephew of a National 24hr Champion, the racing genetics have completely passed him by. After joining the road.cc staff in 2016 as a reviewer, Liam quickly started writing feature articles and news pieces. After a little time living in Canada, where he spent most of his time eating poutine, Liam returned with the launch of DealClincher, taking over the Editor role at the start of 2018. At the weekend, Liam can be found racing on the road both in the UK and abroad, though he prefers the muddy fields of cyclocross. To date, his biggest race win is to the front of the cafe queue.