Stages or 4iiii?


Get a rag and clean that mess… or you get 5w deducted from your FTP :wink:

PS, congrats on the new toy! Have fun with it.


Yeah, noticed it when I took the picture…already cleaned off.


I have heard that people have had good experiences with 4iiii. I wish I were one of them.

Both 4iiii power meters on my crank failed. Sent them back to 4iiii. When I asked for an update, they said it would take 2 weeks to repair. When I asked if it is possible to expedite I received a long boilerplate message.

i only do power on my indoor smart trainer. I have been thinking about getting a stages or 4iii crank on an outside bike or two. When I see experiences like the above, I am like screw it - I don’t need more problematic tech and projects.

My vote for 4iiii. Bad experience with Stages generation one. I know we are a zillion years later, still.
Never had any flaws in the 4 years of using 4iiii.

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Stages Gen2 is fine, I just sold a 6800 left crank arm originally purchased October 2016. Worked great and so did the gen3 dual sided Ultegra 8000 crank.

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Ditto for 2nd Gen Stages for the most part. I do seem to have relatively short battery life compared to my 4iiii models, and the Stages can show those bad power spikes during rough descending if you lead with your left foot coasting. That was a notable and consistent problem when I used it on my gravel bike, but I’ve swapped that to 4iiii and the Stages is back to road/trainer duty and works fine otherwise.


Have got both a gen 2 and a gen 3 stages, never had issues with power spikes. Wonder if it has to do with the crankset/bb? As maybe some cranks flex more than others? Mine are both sram gxp.

Ultegra 6800 factory direct model here, on the typical Shimano BB90 in my Trek Boone, used on plenty of gravel rides with 2k watt spikes on many of them.

Do you lead with your left foot when coasting / descending? From what I have seen, right foot coasters don’t have the problem, just us lefties.

No, right foot forward here. :laughing: But I clip in with my left, and don’t think I’ve seen any power spikes there either.

That’s why you are not getting them (right foot forward). Clipping in would not be the trigger.

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Domane and no gravel rides, and despite living in flatland, I’m also close to rolling foothills and mountains. So a good mix of terrain. Trade off with leading foot while descending. Very very few power spikes. Most of my sprints are 900-1100W peak, and out of 5 years using Stages there were only 3 rides with obvious spikes higher than my all-time peak power bests in the 1200W range. You can 2 of them here (comments below):


The biggest was 1607W 1-sec peak while doing Collins+1 on trainer, mid sprint went from 116rpm to 59rpm back to 120rpm, while power went from 526W to 1607W to 466W. Second biggest was sprinting on a climb, looking at a few seconds before/after, I manually corrected the 1516 down to 1100W (cadence was smooth on this one).

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First test last night at our local Wednesday Night Worlds XC Short track races. No spikes and I did have two left pedal strikes. Only problem I have had is I can’t calibrate it through my Bolt, it fails every time…I have to use the 4iiii app.

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I have a lot to say about 4iiii PRECISION left side 105 5800 unit. When it works it works amazing, no dropouts, no spikes, no problem with coasting and solid numbers. But when something happens your only option is to send it back to repairs.

Bought my first unit back in summer of 2018. Worked fine one year until power numbers suddenly dropped for about 50%. Zero offset, factory reset, firmware upgrade and new battery did not fix it. Sent it back and got a new one under warranty.

The new unit lasted exactly 3 years (summer of 2022) until the same thing happend. Power numbers drop by even more than 50% this time. Because it was out of warranty I had to pay for factory repair. 140€ + 70€ shipping and I got it repaired back to my house in 3 week.

I left it in the box and installed it around christmas 2022. It failed again on the 2nd ride. They said that I can send it back under warranty but have to pay for shipping. Shipping from my country to canada is 110-120€ so I am currenty looking for a new Stages unit.

Credit where credit is due, their customer service is very responsive and very helpful, but I just don’t trust 4iiii anymore.

I’ve had multiple stages units and they’ve always “just worked”. I have an old unit that has had a few power spikes on low battery. The numbers coming off my multiple one sided stages match my quarq as far as I can tell.

I have first hand experience with stages customer service and can say it’s great. They will send you small parts for free.

Personally I have no experience with 4iiii but I would recommend stages overall, especially if budget is an issue.


I’m going to repost my old post as a PSA. If you have a Stages, do yourself a favor and pay a few bucks for some Duracells. Get the retail pack, not the generic oem multipack off of Amazon that could be fake. Since paying retail for batteries my Stages has been rock solid and they last longer than the 10 pack cheap batteries.

I have stages and I agree… it “just works”. No problems for me, ever.

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same here, gen2 Stages in late 2016 and then gen3 dual side Stages a few years later. One side of the gen3 went bad and was replaced. Otherwise just worked. And both Stages and my current Quarq all gave consistent power and no weird issues with buying one and seeing ftp changes.

Are you saying you don’t see the power spikes with the 4iiii that you saw with the Stages? I, too, experienced the power spikes with Stages, which led me to stop using them.

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Correct, the 4iiii does not have those spikes. It seems to have some “smarts” in it to catch / prevent those issues, that the Stages lacks.

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