So not possible to zero mid race!! (I am planning on using for CapeEpic).
Is the maximum drift you have seen 10w?
So can this be a problem on rides going through big temperature changes? One would expect temp compensation to take care of it but exceptions exist.
I do not recall any test involving this. Very hard to do unfortunately. Would be interesting to see the results considering gold standard(!) SRM did not have temp compensation for generations.
I also canāt seem to figure out what Garmin Rally does with calibration and temperature-compensation. I calibrate my pedal in our basement where the temperature is about 16-17 degrees Celsius, then I go for a ride at 2-3 degrees (1-2 hours, no stops for autoacalibrate to take place).
I saw some instructions that itās best to stop and calibrate 10 minutes into the ride. I never had to do this with my other power meters and I find that is quite the hassle, so I just hope that the the pedals will compensate such a large temperature drop appropriately without me having to do this during the ride.
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@dcrainmaker goes into this in some detail on this here: Rally Power Meter In-Depth Review.
Iām wondering if calibration at started of ride is enough in my use case. I drive 40 minutes to my gravel route then calibrate right before my ride. So Iām their scenario needing to calibrate to account for temp differences between inside and outside by stopping 10 minutes into a ride itās assuming one is walking out the front door to ride from oneās house. Unless Iām
Misunderstanding.
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Regarding the XC100 - Donāt buy them
Initially they read about 10W lower than my Infocranks and I was like āfine - Iāll just adjust my FTP 10W lower to suitā but now Iām not so sureā¦ It makes me not trust the āaccuracyā and therefore Iām always frantically getting of the bike to calibrate!! MID WORKOUT! Not trusting the PM is a huge issue and really takes away from my focus of hitting the workouts.
*this problem I have now accepted - although effectively losing 10W to your āftpā takes a bit of a hit to your ego, this obviously doesnāt have real world consequences of course and āits just a numberā but we fight hard for each watt right!
With my infocrank - I found it to be very accurate and after while I could base my workouts of RPE. I.e. 280 feels like thisā¦ 290 feels like thisā¦ and the XC100 has completely messed up my internal PM which is a big factor given I do all my workouts outdoors and donāt use ERG.
However -
I havenāt found a bike shop with a pedal torque wrench yet so I havenāt done that yet - although I have tightened it to my best!
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Have you reached out to garmin? I get the frustration and I havenāt had the same experience as you. They have been great with oany problems I have with any of their products. Theyāll probably replace the pedals for free!
With calibrating before every ride, every power meter needs to have it done. I never calibrate mine mid ride and havenāt noticed a substantial drift, although I donāt run another power meter at the same time. I would reach to garmin and have them hear your complaints and try to get a new pair or refund if it upsets you that much.
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I have read this article and it is actually the reason for my confusion - what I got from it is something in the lines of āit is best to calibrate 10 minutes into the ride, the pedals do something in the background, we donāt want the customers to worry too much about itā.
When I go out to ride my bike I have no desire to stop and fiddle with some sensors, I prefer to do this before my ride. Sometimes it takes a few tries for my Garmin pedals to calibrate without getting an error, I definitely donāt want to hang out on the side of the road in the cold and play with my head unit. I donāt have to do this with my other two powermeter systems, so Quarq and Favero must have figured it out somehow.
āFor the best results you will still want the bike to have fully adjusted to the temperature it is in and then do the zero offset calibration. We expect that to take about 10mins per 10Ā°C. If you were to calibrate immediately, you would be setting the zero offset based on a temperature thatās likely much closer to what it was inside.
ā¦
āLike I said, this is an area Iād like to improve going forward and we have some ideas around how to do so. I donāt want our customer to need to know all of this and even more importantly, we want to do everything we can to prevent a ride with inaccurate power data that can then influence the riderās training guidance and our quantification of their fitness.ā
To be completely fair, itās not a super fair complaint when you havenāt installed them as directed. These pedals are very sensitive to torque setting, and the wrong torque will throw off your power readings.
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The pedals donāt require a specific torque (other than the one typical for safe pedal assembly).
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GarminĀ® recommends torque of 25 lbf-ft. (34 N-m).
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I found that without proper torque my XC100 read obviously low. Once i acquired the Park tool and torqued to 34nm (which is tighter than I would normally do) the power readings are in line with my other power meters.
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Of course they recommend a torque but they donāt write the pedal accuracy suffers if not adhered to. For me this is the safety relevant torque.
Quoted DC Rainmaker article:
Getting the Rally power meter installed is the same for all three versions, and requires just a pedal wrench. If youāre coming to these from the days of Vector 1/2 where you needed a torque wrench, thatās not really necessary here. But yes, youāll need a pedal wrench, because, like almost all other pedal-based power meters, the spindle houses the electronics (so you canāt stick an Allen wrench in there). But I suspect most people considering a pedal-based power meter will have a pedal wrench. If not, they cost $15-$25.
I understand what youāre saying, but the reality is that in real world testing, itās been shown that setting them to the proper torque improves accuracy.
Personally, I find that torque EXTREMELY tight and impossible to remove the pedals without a cheater. My LBS has the same issue.
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I get that but this is what they recommend for installation since you said they didnāt recommend it.
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Sorry, maybe the way I wrote it was a bit confusing. What I meant is that there is no recommended torque only under which the pedals operate accurately. The 34 Nm is pretty tight. 
Shimano recommends between 35-55Nm for their pedals.
Anyhow, I also have the feeling my Rallies read a bit low but I see no way to prove it on the road.
In the beginning I had some power spikes of 1000+W while the cadence was dropped to 0, which bothered me and I contacted support but they said nothing they can do about it and keep observing. Hasnāt really happened to me lately though.
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I wrote this a while back and it helped dropouts I was having, since doing these steps theyāve been seemingly reliable.
Try this.
1: Make sure you torque the pedals down
2:Reset all angles
3:calibrate
If you want to add another step take out the batteries for a couple minutes and do those 3 steps. Always calibrate before every ride and reset all angles if you change the pedals to a different bike.
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I have XC-200s I have run them indoors and compared to both a TACX Neo and KICKR Core. Thus far theyāve been what Iād say is close enough considering the differences between them. I have quite a few rides that I uploaded into the DC Analyzer. I do not torque to spec everytime but tend to follow DCās procedure (I do not have a torque wrench at my alternate training location).
Sorry to hear you are having problems and that Garmin Support is not helpful. Iāve had good experiences with them in the past (U.S.).
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Thanks for the tips!
But this is quite the hassle, isnāt it? The pedals were supposed to be easy to take on and of the bike, switch between bikes, switch pedal bodies - road/MTB etc.
If I had to deal with all this, Iāll get rid of the pedals and switch to a more reliable and user friendly product.
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Agreed. Never had these concerns with my faveros. I bought the xc200s because I wanted them for my gravel bike and didnāt want to do the spd hack for the faveros. I previously tested my faveros against my elite direto just to see how they matched up and they were almost spit on. Now Iāll have to compare the xc200s against the direto to get a sense of how they line up.
I always trust the faveros as gplama and dcrainmaker have stated many times how accurate they are.
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