Anyone using left only pedal based power meter?

[tuxbailey]

I asked in a different thread about calories estimation and then the overall consensus is to get a PM for actual riding if I am interested to know more.

I am not riding/training for races/events outsides of charity rides or organize centuries. I do the MS Bike ride every year and I am toying with the Civil War Century this year. I did the CWC 78 miles option before and that was at the edge of my ability 15 years ago.

I have never considered a PM because:

- I am not training consistently for an event.
- Too expensive.

So I search through this forum and the web and seems like the Favero Assioma had gathered a lot of favorable reviews. They have left only (Uno) and Duo and the price difference is not insignificant.

I am thinking that for my purpose the Uno is sufficient and I want to see if anyone has experience in that setup, as well as other left only option.

Thanks in advance.

[BobO]

The 4iiii left only unit works great. I've had mine on my race bike for over two years without changing batteries. It produces (apparently) good consistent data with no fussing with it at all. They can often be had for excellent prices. If both your legs produce similar power it's going to be just fine for measuring calories burned. I have a pretty wide discrepancy between my legs due to an injury. I went to a shop that had a dual setup I could use a few times to try and find the difference between them. The 4iiii calibration app allows you to scale the data to fit what you learn from the dual. But again, my discrepancy is significant and for most people who aren't racing it won't matter.

[tuxbailey]

Originally Posted by BobO

The 4iiii left only unit works great. I've had mine on my race bike for over two years without changing batteries. It produces (apparently) good consistent data with no fussing with it at all. They can often be had for excellent prices. If both your legs produce similar power it's going to be just fine for measuring calories burned. I have a pretty wide discrepancy between my legs due to an injury. I went to a shop that had a dual setup I could use a few times to try and find the difference between them. The 4iiii calibration app allows you to scale the data to fit what you learn from the dual. But again, my discrepancy is significant and for most people who aren't racing it won't matter.

Awesome. Thank you for the input.

[weiwentg]

One thing to consider is that left-only crankarms seem to be the cheapest option. Stages or 4iiii will factory install on your crankarm for $300. Favero's left-only pedal solution is a bit over $400, I think. The factory install solution at that price is limited to Shimano and SRAM cranks, with 4iiii also offering Campy Potenza crankarms plus a few FSA and Praxis ones.

[BobO]

If you watch for sales and promo codes the 4iiii can be had for less than $250 factory installed on a new 105 arm.

[raisinberry777]

I purchased the Assioma Uno three months ago as my first power meter after seven years of riding. I chose the Assiomas as the only crank based option for Campagnolo is a 4iii factory install, and being based in Australia I had no desire to wait 4 weeks for postage both ways plus installation.

I was hesitant to buy pedals as I have been using Shimano SPD-SL pedals since I started riding and have continuously been impressed by them. However, the Look system used by the Faveros works virtually identically. Once clipped in, I would say that the feeling is indistinguishable between my 105 5800 pedals and the Assiomas.

Reliability has been rock solid (although of course I've not had them for long). I chose the Assiomas as I'd heard numerous failure stories from Garmin Vector and Powertap P1 owners across the internet, and nearly all Assioma owners seemed happy with their purchase. The only issues I've heard of with the Assiomas are some people experiencing faster than usual battery drain, but I've had no such issues.

Speaking of battery life, they'll only need to be charged once every one or two months. It will make your life a bit easier if you have one of those USB battery banks, as you can sit that in the bottle cage and have the cable run from that to the pedals rather than try to manoeuvre it near a power point.

Finally, as to left side only, it hasn't bothered me at all. I would only be concerned if you're trying to compare to another power meter (eg smart trainer) and desperately need comparable results between the two. As for me, it's my only power meter and I have no issues with consistency of my results between rides. I thoroughly enjoy having power data for longer climbs and consistency of effort on the front of group rides.

My only (and very minor) criticism of them is that they tend to spin a bit more than Shimano pedals, making them a little more difficult to locate for the initial clip in. As I've said though, once clipped in, it's indistinguishable.

TL;DR: very impressed with mine, definitely worth buying.

[papa bless]

I just got the Favero Assioma Uno setup last week. I absolutely love it. It measures power and cadence, making indoor workouts super convenient.

For my purposes, I didn't think the Duo was worth the cost. I'm not so concerned with achieving a perfect 50/50 power balance between my legs, and left-only power is consistent enough to develop a training baseline and have a general idea of my power on outside rides.

Let me know if you have any more questions. I've been recommending these pedals to everyone I know. They're cost effective, and super easy to switch between bikes. I'm sold.

[mudhead]

I have both a 4iiii left crankarm (ultegra 6800) and the Garmin Vector 3s. The 4iiii has been rock solid and ridden on off-season road rides, sloppy roads, mud-fest CX and Gravel Grinders. The Vector3s was replaced under warranty after about 2k mi due to an issue with the battery door. Since the swap it has been about 4.5K miles and no issues to report.

If I were to replace the Vector3s, i'd go with a dual sided option since the prices have come down. Since the 4iiii on a bike with SPD pedals and subject to abuse, It's unlikely I'd consider a DS option for that bike.

YMMV

[Spaghetti Legs]

I have the previous generation single side BePro. I've had it 3-4 years and it has held up well and works reliably. I've never been too concerned about difference in power output, left vs right, as long as the data is accurate between rides.

I'm not a heavy power meter user. I mostly leave mine on one bike and occasionally switch among a couple of others. I have - a lot - of bikes so the BePro doesn't get a lot of hours use, but I've been happy with it.

[tuxbailey]

Thanks for all the input.

It seems like Assioma might be a better choice as I didn't realize I have to send my crank to Australia to have it installed.

I assume once it is installed I can't transfer it to another crank? That makes component upgrade tricky.

For those with Assioma, is the spindle with the pod the same length as standard pedals?

Also, anyone use Keo cleats instead of Xpedo cleats?

[Malinois]

Originally Posted by BobO

The 4iiii calibration app allows you to scale the data to fit what you learn from the dual.

I had no idea that the 4iiii single could be adjusted to take a known L/R imbalance into account, that’s freaking awesome. Thanks for the info.

[tomato coupe]

Originally Posted by raisinberry777

I chose the Assiomas as the only crank based option for Campagnolo is a 4iii factory install ...

Stages does factory installs on Campy cranks.

[BRad704]

I switched from Left Only Stages crankarm to Garmin Vector 3s (left only) so that I could swap easily amongst bikes. 10/10 would buy the Vectors again.

[Spdntrxi]

I currently have

Stages gen 1,2 and 3
Vector 2 and Vector 3.

Granted I know my mix is nearly 50/50 verified by years of ownership of dual vectors.. I have no issues using left only stages.

[Lanternrouge]

Originally Posted by tomato coupe

Stages does factory installs on Campy cranks.

This included Campy carbon cranks, though it's $100 more than aluminum cranks. I think that it's about a wash pricewise adding Stages to Campy carbon versus a Favero Uno.