4iiii Precision Power Meter (LEFT Side Shimano): Details // Data Review
A power meter review in under 5 minutes? Let’s give it a shot Today I am diving into the 4iiis precision Power Meter It’s also known as the Precision 2.0 or the Precision 2.0 3D. The specs of what I have here and on the bike are… [Reading the Tech Details listed on screen above] With the accompanying app from 4iiis you can… [See App Details Listed Above on screen] And when performing a zero offset on this power meter it will return a helpful code, not just or something random. If everything is OK it will return 10 for the left side. If you have left and right for the dual sided it will return 10 10. Other codes are listed here [on screen] i’ll put links below but it’s kinda handy to know things are OK after you perform a zero offset. Time Check? We are still looking good!
Over to here quickly to DCRainmaker’s Analysis Tool where we can compare multiple power meters as an overlay and see how they stack up. My outside ride here, 2hrs up against the Assioma Uno. I split my DUO to an UNO so we had left pedal and left crank recording Fair decent ride here. We will dive into the data for this climb here. 306w vs 309w. Now the way this records power is differently to the pedal. Every different power meter will record differently. So you will get slight variances and what we are seeing here in those slight variances is the spikes. So in Purple, the 4iiis is a little spikier and the dips are a little lower You can see here, but not too bad overall. Another little climb, for some steady state stuff here and here. 254w vs 253w very close, but again a little spikier. One short sharp acceleration (not quite a sprint) here at the end and the 4iiis gets the jump on the Assioma. It is the UNO, it does say DUO on screen, that’s just what I’ve got them labelled as. It is the single sided power meter on both and they record just a little differently and that could be due to number of different factors A longer sprint is probably going to be a better test for this It wasn’t too bad once things came into alignment they tracked ok and I was already done by then. A standard Llama lab test, a little short though as there is nothing that is going to effect this with temperature It does have active temperature compensation so it should be good there. Looking at the Llama Lab test. So we have the Assioma UNO, Tacx Neo and the 4iiis Dura Ace left only. Hard to compare directly with the Neo as the Neo is both left and right total power, the other two power meters are left only and doubled. We have 229w vs 224w vs 223w. Depending on how you want to read the tea leaves today, which one you think should read higher or lower depending on where things are at. It’s close, but we can see the spiky one. Again it’s the 4iiis and it is spiking down quite a bit For example i pick one data point here. It reads 177w for that specific point in time there that is raw, un-smoothed. Why it reads 177? I am pretty sure I was not doing 177 on the pedals at that time. Close though. Very close. Into the sprint, this time the Assioma gets the jump. It’s been flipped. It’s just the nature of things with single sided and the recording intervals. And once time goes on 3 seconds they all line up here. It’s close, no cigar. If you want killer accurate sprint power, get yourself a Left-right power meter as close to the pedals as possible. The crank or the spider. You know what I’m talking about. It’s close. Just riding along: 136w vs 136w vs 138w. Cool, Happy Days. Flipping over to the overs and unders. I had one hell of a drop out session there at the back half of the 450w section. Other than that ll looking pretty good, given it’s Left and doubled. It’s going to be a little wonkier. Still a little spikier. Here – Just short. Over here when I do drop. And there is an actual drop. Both power meters on the left do drop. The 4iiis again is a little spikier. And then just some riding along. Some short hard effort there at the end. 155w vs 152w vs 152w. All looking pretty good. Again some red spikes there from the 4iiis. Final time check: We’re good! And it’s time to wrap this one up for today. So in summary, pretty much what i expect from a single sided Shimano left hand power meter. The numbers outside against the UNO – Fantastic! Indoors – not too bad! But i really would like to see that data smoothed a little bit so we don’t see that data number jumping, even when we have on 3 sec smoothing. So there we have it. My take on the single sided, 4iiis Shimano based Precision Power Meter Links below for more details on this. And as always remember to hit that thumbs up to subscribe and support what I am up to Thanks for watching.