4iiii Precision Power Meter (LEFT Side Shimano): Details // Data Review

A quick look at the 4iiii Precision Power Meter (LEFT Side Shimano R9100) that I've had on the bike for a few weeks.

Details: 
- Shimano R9100 LEFT only crank (172.5mm). Single sided.
- Available on Shimano 105 to DuraAce cranks. 
- Claimed Accuracy: +/-1%
- Dual ANT+ and Bluetooth Smart.
- Data: Power + Cadence. 
- Battery: CR2032 ~100hrs useage. 
- Weight: 9g. 
- Optimal operating range 0°C - 50°C. IPX7.
- US$349-$599 
- Frame clearance: 4iiii template to print and check your frame. 

Links:

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#4iiii #powermeter #cycling

[rzeckner]

After making the mistake of purchasing and then suffering with the Powerbeats product, I found a deal on the 4iiii left side crank (Ultegra) and I couldn't be happier. Like Wahoo, they seem to make a product that simply works! For most riders of my ability (real and imagined) the minor differences between perfection (or your standard) is of little value but reliability and consistency rules the day. As always, thank you for producing both entertaining and informative videos.

[pstizz]

Iv had a 4iiii for almost a year. The non drive side. Been great, I recommend it and it's all u need. It has a scale factor you can program to compensate for left right leg strength imbalance.

[WowRixter]

I've got the 4iiii PM on one of my bikes and love it. Great customer service too if you have questions

[ArcticSteam]

For an absolute amateur such as me, it seems pretty ok. Nice, as I was lucky and got a very good deal on it and has been using it this summer.

[mrskeltal]

I bought one recently for about £220 to put me on until my iQ2 dual side arrives (if ever). Absolute bargain. Very happy with it and reads very close to my Wahoo Kickr.

[utterlyexiged]

I've just picked up the 4iiii ultegra for £285 delivered. Works a treat and pairs perfectly to my garmin. It's great having all the data while out on the road.

[alexanderwendelbo]

thanks!!! hopefully the piggybank is full in march, ready to hit the roads again with a powermeter on the bike

[quicksheep]

Been using this one for a while, more than happy with it. It's not ridiculously over generous with the power readings, and certainly doesn't steal as much power as Strava!

[davidh]

Shane, This is a very timely video. I owned an identical left leg 4iiii power meter which was amazingly accurate and tracked my NEO perfectly... Until it just stopped measuring torque. Cadence? no problem at all, but just Zero watts always. It could not be fixed and was out of 12 month warranty :(
Problem is, my friends 4iiii also just stopped measuring torque too. Cadence was fine again. Both of our 4iiii's failed between 18-24 months of use. Do a search on the web and you will see our story repeated many, many, many times. I am convinced there is something inherently wrong with the 4iiii strain gauge or bonding cement. While initially ok, consistently fails within 2 years.

I don't want to throw shade on what is an extremely accurate PM product but I warn potential buyers to research the long term ownership information that is out there.

[eljamo]

just bought a refurbished 105 and i'm very happy with it. the 3 second power does take some time to get used to, because the numbers aren't given immediately

[Taihaki]

Just bought the 4iiii Precision 3 Power Meter when they had a 15% off which is the regular price on the Precision 2, really good price and all I needed for my bike computer to work with, thanks for the review, hopefully you can do the precision 3 review soon

[DKiwi]

Got a 4iiii on my indoor bike. Power data is very close to my Assioma Duo pedals. As mentioned by others the 4iiii company gives great service. Recommended by me if you want a low cost accurate power meter.

[dr_taka]

The best bang for bucks. Cheap enough for my commute and work on zwift too

[chechoa]

Great review and thanks for the great data, I just bought a 105 left PM and I love it it has change the way that I train and pretty reliable, ill be checking out the spikes that you mention when I do my first FTP test, good review and awesome work please do keep up!

[markharvey]

Thanks for the review. I just bought one. Cant wait to try it out.

[NathanBudd]

Had this for a while and really liked it. I had an issue with the battery cap breaking the tab on the actual PM part, but 4iii repaired it free of charge. Had to get rid of it recently, as I changed my steed to a Gravel bike with a Praxis Alba crankset :(


Trying to work out the best way to get power on that bike now.

[ryantaylor]

Got the recent duel 4iiii and it’s great.

[mahnamanah]

Hi Shane, considering the ongoing issues with the P3, should I go after a discounted P2, a stages or an assioma Uno? I currently ride with MTB shoes, so the Uno would involve getting new shoes as well, which is why I was tending towards the crank-based ones. Is the Uno so much better it is worth the higher investment?
Congrats on the amazing work, really useful for us!

[martijnestor]

Over here in the EU the 105 and Ultegra models are often found for 300 euros or under at various webshops, making this a great option imo. (I have the 105 version for a year now, no issues whatsoever)

[Tchairdjian]

Hi Shane... I have this 4iiii PM on my Ultegra Carbon bike... and the Garmin 530.. and I used it all summer but, I am embarrassed to say I have no clue how to properly benefit from a power meter... Can you maybe do a session on Power Meters for beginners? Including what parameters to set up on the Garmin... for example, I used the instant power reading at first, then I switched to the 3s reading... I have no idea what I'm doing... what all this means. Can you also point me to some good reading material if possible? I'm just 60 year old amateur rider... not a strong rider.... I do ride 80-120km hilly rides 2-3 times a week in the summer, but my average speed ends up around 19-22 km/h.... Had some extra money to blow so I bought myself a power meter... LOL.