Stages temperature compensation

I wonder if other people have noticed their Stages not compensating adequately for temperature.

Today, my bike was stored inside (75F). I took it outside and let it sit for maybe 5 minutes. I came out, calibrated my Stages (gen 2) with my Garmin head unit and then left on my ride. It was 93F outside with 80% humidity.

I think the initial calibration was 890.

Towards the middle of my ride, I noticed that my power seemed abnormally low. I stopped and recalibrated it (914) and then power looked normal for the rest of the ride.

I guess my stages can’t compensate for a 20 degree swing in temperature? Maybe the humidity?

I’m just wondering if others have noticed these kinds of things. Or, if this is normal. I guess the moral is that if I’m doing any serious power based workouts that I should calibrated after I warm up.

@AJS914 I’ve been taking a lot of data on Stages single sided power meters lately…and orthogonal strain gauge array power meters in general. I was going to publish the data but as I got ready to I balked. It was really a recipe for how to cheat on Zwift and that activity is already so endimic I didn’t want to contribute. And this would have contributed in a big way!

I think Stages temp compensation is pretty good over a commercial range of temperatures. But maybe not as robust as some people might think. The difference you notice is QUITE LARGE. Yikes! So maybe there is some hardware issue with your power meter.

According to my cal factor/watts curve that difference would result in 10’s of watts difference between the two readings.

Bike in garage and summer temps before opening the door, are 70s. Outside in the 90s. I ride outside a lot. Morning rides on the weekends might be 60F at start and end in 90s. Haven’t had any issues with Stages gen2 or gen3.

In your situation I’d call Stages and file a support ticket.

The only problem I’ve had is with Quarq magic zero. Called support and they explained when that can happen, so I turned off that feature and since then no issues.

1 Like

What are they going to tell me? Do a factory reset? Update firmware? It’s already got the latest. I’m guessing they won’t give me a new one as this one is old now.

It feels like it’s been pretty consistent. This was the first ride where I had this large of a temperature jump and a big humidity jump.

I dunno, be polite and see where it takes you :man_shrugging: I’m in sales and get to deal with a lot of ‘fun’ situations. You never know if you don’t step up to the plate and take a swing.

1 Like

I was having temp issues and inconsistency between 2 different stages. They diagnosed the problem and offered a reasonably priced solution. They were great.

I think this might be normal as far as I can remember?

I don’t think you need to worry about what values your Garmin spits out during calibration as a believe that this is related to a raw strain gauge reading - so will be different at different temperatures.

I.e. it records the temperature at the time of calibration and uses future strain gauge and temperature (and cadence) readings to then calculate the power at any temperature.

If you believe you are actually seeing power drift with temperature than that’s a different story.

Could maybe also be the battery, I sometimes have odd readings when it’s nearly empty.

2 Likes

Before my ride yesterday, I put my bike outside for 10 minutes, and then calibrated the Stages with the Stages app before riding. Upon calibration, the Stages temperature was spot on with the outdoor temperature. The power readings while riding looked good.

Moral? Be a little more careful with calibrations? Calibrate after warming up for 10-15 minutes when doing a serious power-based interval session?

Tbf, I do sometimes calibrate a couple of minutes, after I started riding, when there’s a big temperature difference between indoors and outdoors. Though afaik stages say it should be able to handle normal shifts in temperature. Maybe yours is just a little extreme? I’m in the UK, and it’s rare to have more than 10 deg difference between indoors and outdoors.

Mine has seemingly gotten very odd with calibration in the past two months. I haven’t figured out why

Most definitely. On paper this workout looked pretty “doable”, and it was, but it wasn’t easy.

I’ve noticed that my Stages reads lower temp than what my thermostat in my garage is reading. Granted, they are at different heights. As an experiment, I just put my bike outside for 20 minutes to see how closely the Stages would align with the outdoor temp (82º). After 20 minutes the Stages warmed up to 80º.

Let’s say I calibrate right away indoors…

  • If calibrated indoors at a cooler temp then outdoors, will the Stages read lower or higher power outdoors?
  • If calibrated indoors at a higher temp then outdoors, will the Stages read lower or higher power outdoors?

Same.

IME the one thing that Stages PMs are quite finicky about is battery voltage/life.

Based on my experience, if you calibrate indoors at a lower temperature, the Stages may read low outside.

I haven’t tested the 2nd scenario, but I’d guess the reverse. Now, obviously, the Stages is supposed to compensate for the changing temperature but I’m not sure what it’s range is.

So, when you need to rock it on Zwift you should warm up your stages a bit! :slight_smile:

I just changed the battery on it a few weeks ago and I’m using Energizers rather than the noname Amazon batteries. The Stages app says the battery level is high.

Probably, when in doubt do a factory reset on a Stages (install battery backwards for 20 seconds or short the terminals together for the same time). This has fixed all of my issues in the past.

I’m not sure where I read it, probably @GPLama or @dcrainmaker , but I believe if you are going to be moving your power meter from inside to outside you are better off either calibrating before you move it or a long time afterwards.

I suppose it’s not ideal to calibrate while it is actually changing temperature.

1 Like