Power Meter Choice for Checkpoint ALR 5: 4iiii Precision 3 vs. Favero Assioma Duo Shi

I recently got a second bike - a Trek Checkpoint ALR 5 (the other bike is a Trek Emonda SL 6). I’ve been shopping for a power meter for it. Because of clearance issues, there aren’t a lot of options. I’ve got it down to the new 4iiii Precision 3 GRX RX810 (left only) and the Favero Assioma Duo Shi (I eliminated Garmin Rally, the Assioma hack, and various spider-based models). Not that it matters for this post, but I’ve got a Stages left only on my Emonda.

The Duo Shi seems to have two big advantages - dual sided power, and I can use it on multiple bikes (to keep things standardized, I could even remove the Stages PM from my Emonda ad swap the pedals between both bikes). The downsides are price and maybe q factor.

I think I can get over the price difference.

Q factor is something I have no clue about, though. And it looks like @dcrainmaker and @GPLama seem to disagree a lot about this (and thank you both for providing years of reliable reviews that have guided most every cycling-related purchase I’ve made). Given that, I’m at a bit of a loss.

Does anyone here have any real-world experience with the Duo Shi? Will I notice the q factor difference? More importantly, will it increase the likelihood of knee / hip problems (if it’s just a harmless thing I notice, I can get used to it; injury risk is a much bigger deal to me)? I’m not very tall or wide-hipped, but I don’t think I have narrow hips. Both bikes are 52 cm.

Any help would be greatly appreciated. I’m trying to avoid buying the Duo Shi, riding for a week or two to get an idea, and then not being able to return them because of use. The super safe route seems to be to just get the 4iiii.

Thanks!

Well you shouldn’t have :slight_smile:

Really happy with mine.

That said, I really don’t think you will notice the q-factor on the “shi” with regards to bike fit but you may with clearance issues.

I think GPlama’s issues with the q-factor are as much to do with the pure lazyness of the “design” than anyting else. I think we were all hoping that a shimano version of the assiomas would have a better way of dealing with the pod than just adding the width of the pod onto the q-factor.

I was told it voided the warranty. I also know it requires tools (and maybe expertise) I don’t have. Given those two things, it seemed like a bad idea. But that said, it does seem like a “better” solution.

Devil’s advocate here… Q-Factor and actual Stance Width (final shoe width in use) may not matter to everyone, but it will matter to some. Chances are that those with the potential issue are already aware of it and would know if the 10mm per side (20mm overall IIRC) will or won’t be an issue for them.

As a fitter, I have seen as little as 5mm per side help or hurt a rider, so I fully believe the concern is not just about “laziness” of the designers. That said, it is possible to minimize that width gain a bit by applying the maximum wide cleat position under the shoe (which gives the minimum Stance Width for any pedal setup) to keep the gain to a lower level. But no cleat setup I have used will be able to eliminate the extra width entirely. At best, you may be able to cut about half the gain, which might be workable for many riders.

It’s a valid consideration at the very least, even if it is negligible for many, it is not so for some riders.

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I was worried this was going to be the answer - it may or may not matter, and there is no way to know without trying. That makes me want to hedge to the safer choice - 4iiii.

Does anyone know how Favero handles returns? Would they accept an undamaged return after installing and using for a week or two? Also, any clue how long it would take for knee or hip pain to show up?

Lots of people downplay the q-factor difference, but I think you should be affirmatively sure it won’t bug you before you go that route. I have a pretty wide stance and i really didn’t like the added q-factor. I strongly suspect that anyone who isn’t bothered by the q-factor would also not be bothered by switching to the original assioma cleats(might be worth considering this as an option).

The other consideration is wether your l/r balance is stable. If you already are happy with a left only power meter that’s not an issue, but it’s worth thinking about as a source of error if your current power meter is behaving unexpectedly.

Thats fair enough.

Although i dont really see that assembling the shi could be any easier than the “hack”.

Dont see how it could void warranty… unless you told them.

I’ve had a 4iiis crank on my Roubaix for 5 years and basically just worked, no issues other than stressing about how much battery was left in the coin cell battery.

I just added the Wahoo POWRLINK dual-sided and the primary driver was really to get power balance between both sides. Though, if I’m being honest, I’m not yet sure what to do with the data (one leg is stronger than the other but now what).

Dual power is good for total accuracy but your right that there isn’t much you can do with balance data.

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Ditto. Apart from getting potentially more accurate power data (true dual vs single doubled), and assuming you don’t have a legitimate functional problem in the form of pain or injury, I’d ignore the imbalance data.

Think about it. You know now about something that was already (and always?) the case. But that data doesn’t need you now have “something to fix”, unless you know there was an issue before that this data now correlates to.

It’s funny. Right after I decided to be conservative and just go with the 4iiii, it went out of stock everywhere (170 mm). Power Meter City had it when I originally posted.

Guess I took too long deciding.

Will

I’m a little late to the recommendation party, but recently purchased a rotor ALDHU Power2max for my Trek Emonda SL6. While considering pedal, crank, and spider based options, ultimately, I settled on the above spider based option. The general thought process was as follows:

  • Garmin dual-sude power was more than I wanted to pay - especially since I wanted shorter cranks and left-right balance data.
  • Assioma with the increased Q-factor on the duo-shi’s didn’t make sense for my Shimano preference. It’s less of an issue if you use look cleats.
  • Cranks were ruled out because I’m on Shimano Ultegra and have little confidence in the dual-side setup for accuracy based on known flaws. As such, left side only would have been the option, but that didn’t work for the left-right balance requirement.
  • Quarq was considered, but the loss of the GXP required a bottom bracket conversion to align with the SRAM dub standard. As such, I ruled this out.

Overall, I found the Power2max NGeco with rotor ALDHU was the best balance of my needs (e.g., shorter cranks, accuracy, balance, cost, etc.). Hope this helps!

I’ve also got a power2max on my Checkpoint ALR 5 (2019). No complaints. I use it inside with TR’s PowerMatch, which also works great.

I was in the exact same boat as you. My Emonda has a left crank stages that I’m very happy with.

I acquired a ALR5 at a very solid deal and found that there’s no clearance for any left crank PM on this bike. In the end, I was in between the one side Garmin Rally and the 4iii Right Side PM. I ended up going with the latter. I ordered the Shimano GRX FC-RX810-2 2x11-speed Crankset 48x31t that I found at a pretty good deal, at $235 with free shipping.

As soon as I received it, I sent it to 4iiii for Factory Install for $300. To five you an idea of the timeline:

  • 4iiii Received my crankset on 01/21/22

  • Crankset with PM installed was shipped back to me on 02/03/22

My reasoning was that I would end up with a better crankset than the GRX600 that came with the bike. And that I could then use it on any future gravel bike I purchase. Plus some of the gravel bikes I’ve been looking to upgrade to in the future come with non-GRX brand cranksets, something that personally I don’t like and the Garmin Rally’s wouldn’t have helped me tackle that.

I have both, on different bikes. Technically they are perfect, both have no problems. I was a bit reluctant about the non replaceable battery on the Assioma, but the charging is easy, very long battery life and clear warnings.

Still I would recommend the 4iii. As the increased Q factor really gave me some problems for a couple off weeks. After I compensated by moving the cleats to the extreme it now is ok, but still not as good as the original pedals.

P.s. I bought the Assioma two of have dual sided data and some data on dynamics, but after the first two weeks I never really looked at that again. I’m very close to 50/50 left/right power. Single sided is fine and honestly all you need.

I have the assioma shi on my gravel bike. No problem with the q factor - in fact I actually find it more comfortable than my road bike with “normal” shimano pedals.
The conversion is very easy, I did it myself and I’m by no means a bike mechanic - as for the warranty who is going to tell them??

As far as Q-factor is concerned, it just depends on you as a cyclist. If you have a more narrow frame, find yourself already stretched to your limit on fit because you’re on the shorter side, or any number of reasons then an increase in Q-factor may be an issue. Alternatively, others won’t be bothered at all and some will find it more comfortable. A buddy with tight hips finds the increased Q-factor more comfortable based on his biomechanics. I recommend looking at your bike fit holistically and considering Q-factor relative to crank length, flexibility, etc.