G’day team,
Bought a cheaper bike for keeping at my parents house for trips home (travel long distances overseas, easier to just leave a bike at their place).
Picked up this polygon on sale. Looking to add a power meter, not overly familiar with Apex.
Can I drop this crank arm onto the bike and call it a day?
Thanks all.
If you are ok with a left-side-only power meter, that’s probably your best option. Otherwise, I’d look into Favero Assioma SPD power meter pedals (the dual-sided version, obviously) or a new crank with a Quarq DZero power meter.
Thanks Mate,
Not getting super in depth on this bike, just want figures purely for structure. Sounds like the way to go.
Yep, bought an apex pm for my gravel bike, didn’t fancy bashing up my Garmin pedals off road. Found the single sided PM good enough to get through workouts with. On the the plus it wasn’t silly money and was pretty simple to fit.
I’ve the inside the axle one, it’s garbage. sometimes it’s 20% off above, sometimes below the real value, sometimes it gets the same error for the whole ride, sometimes it shifts completly.
I spent the last 20hrs of riding indoor comparing the values with favero and the trainer, the sram axle one it’s usless.
That’s most likely because your left/right balance changes significantly. Meaning the actual power measurement could be 100 % accurate and still off by 10 % if you shift from 50/50 to 45/55 or 55/45.
However, if you use the power meter to pace yourself and to get TSS values for outdoor rides, a one-sided power meter might still be enough.
FWIW: Of late, I kinda like the spider PMs from Magene or Sigeyi. I have a left side spindle pm, Assioma Duos, and a Sigeyi spider PM, the Sigeyi being the most recent. If I was getting another PM now, I’d very likely get another spider.
Thanks all,
I think I’ll do the upgrade.
I got 50/50 or 51/50 After every ride with Favero pedals, so i’m pretty sure thats not the case, 20% over avarage in 2hr it’s not because of the single side.
Im testing the pwr meter on the trainer lately, Just for fun because I get bored on the trainer.
It’s Just useless. Some times you can calibrate the shitty thing pretty accurate, and After a 30 mins It goes totaly nuts in the opposite way. In a ride It goes ffrom -20% to 10 15% over the real value.
I use Favero/kickr Reading to compare It and they are Always really close, so I’m pretty positive that the axle One going nuts. But you can tell it any ride, some times I cant get too 200w without dying.
Maybe mine it’s broken. I dont know.
Btw today I tried to put the Favero on single side mode, It performed as It should, far from the axle one.
Those are averages across the entire ride, correct? If so, then this does not address the issue. My averages are pretty stable, too, but typically vary (in the moment) between 50/50 and 55/45. The imbalance is more pronounced when I am fatigued and/or have to rely on my muscular endurance.
PS The Favero in their Uno/one-sided configuration could still be better, but my point is that if your left/right balance varies significantly, this can be at least as big as any other measurement errors. Hence, my proviso “if you are ok with a one-sided power meter”. 
I’ve got the Favero Assioma MX-2 pedals. Been running these on a gravel bike for about a year now on both gravel and road and they have worked flawlessly. Would recommend
You should check out 4iiii. Their left side PM is perfect for your needs. I’ve bought 4 from them over the years for different bikes. The company support has been excellent whenever I have had an issues.
I really cant see any argument for anything that’s not Favero. I’ve had other PMs and Faveros are the best. I’ve done multi day bike packing trips in pouring rain and I’ve had pedal strikes on probably every rock in the state of Maine. They still work flawlessly and accurately. Not to mention if you want swap them to a different bike it takes only a couple of minutes.
Before purchasing the Favero RS-2 pedals I recommend checking the long thread of them in the WW forums. There has been various issues with the pedals.
I can use the favero as right side only to show how poor the qark readings are. Tomorrow I’m doing a gravel ride with my mum (66) so I don’t really care of the readings, I’ll use them both and see what comes out.
My n=1 experience with the 4iiii single-sided power meter, some google searching tells me I’m not alone in this either. Used one for ~5 months with no issue but then it suddenly started draining batteries. Talking having to replace the battery EVERY ride. 4iiii support was initially helpful in troubleshooting and eventually determined it was defective and would be replaced under warranty and then… they ghosted me.
Went over a month with no reply at all. Contacted the company I purchaesd it from (biketiresdirect) and they said they’ve seen similar customer service complaints about 4iiii. In the end, biketiresdirect ended up replacing it for me, no idea if it was out of their own pocket or if they were able to get it warrantied by the manufacturer. I sold the new one as soon as I received it and got a spider-style from Sigeyi and it’s been great.
Yikes. I moved from Stages to 4iiii, and now they’re falling out too?? 
I haven’t used my PM in a while, since I’m exclusively riding inside right now and just use my trainer, but I noticed the other day that it wouldn’t turn on, so it seems like my battery is draining as well…