Do folks have a general timeline for when to run calibration on their indoor trainers?
My trainer is in my garage/office which cycles from around 7c to 16c during the day. Normally i calibrate at the very start, before starting the workout. Only thing I’ve noticed is the power levels tend to become noisier towards the latter half, but the average power target over the duration is “correct”, in quotes given that its a single source of truth without external validation. Running a Tacx flux 2.
Is there any benefit to doing it after the warm up portion or another time in the workout? My only guess is that the belt/components warm up a bit first but not sure if that really is consequential at my power level.
I use power from my pedals these days so don’t care too much about trainer calibration, but back in my wheel-on trainer days (Tacx Vortex that was VERY susceptible to heat related power drift) my general rule was to calibrate at the end of workouts.
This meant that the trainer had time to heat soak and stabilise, and it was then calibrated to that condition (outside temperature probably won’t affect it too much either as the heat generated during the ride will even that out).
End result is that for the majority of the next workout you’re probably calibrated right, and the time the calibration is off is likely during the warm-up when accurate power arguably matters less.
The only time this falls down is if you have to take the bike off the trainer or move the trainer between workouts. I’m sure there are other flaws but that was always the logic that sat best with me.
i suppose i could use the power from my pedals. Only have a single sided assioma mx though, so i find its a bit over the map a bit, but that could just be an actual unbalanced strength issue between legs…
Follow up, given the option to use the power from a power meter vs trainer power, whats the preferred?
I have dual sided Assiomas so for me it’s a no-brainer to use them for consistency inside vs outside and consistency between bikes. For single sided I agree, it’s not as clear cut though.
I’ll calibrate my power meter every ride, but the trainer will be uncalibrated for months. With mine (an Elite Suito) you’ve got to warm up the trainer, then spin to a certain cadence, hold it there for a while, then release it for what they call a ‘spindown calibration’. Its a bit of a workout in self. With the powermeters, it’s just a case of waking them up, unclipping, putting the pedal to 6’oclock then pushing a button on the garmin. If I didn’t have a powermeter I’d be recalibrating the trainer more often but with its rigmarole to do so it probably wouldn’t be every ride, maybe weekly.
I gave in to the temptation. I’m just hoping they come soon. Lol, I got an email from a 3rd party ShippyPro claiming they were shipped 2days ago. But they have a disclaimer, they are not the seller or the carrier and to go to the FedEx tracking site. When you go to the FedEx site manually, the tracking details check out but they’ve not even received the package yet, despite getting the shipment information 3 days ago!
Edit lol, before I even finished typing FedEx have given me delivery date I wonder if I’ll see any difference to my power data with double sided instead of single sided. (I have a 2017 Be Pro S, but it can’t be swapped easy and a 4iiii V2 crank)
The Elite version probably makes more sense for warming it up a bit and probably better but haven’t noticed any issues just doing it via TR and the quickly spin up/down.
Hard to say as I went straight in the deep end with Dual sided. Not sure I can ever go to single sided though as it’s made me aware that my power left/right balance isn’t just uneven, it varies with power output.
At recovery power I’m about 54/46
Sweet spot is usually bang on 50/50
Abive threshold goes the other way at about 48/52
So with a one sided measurement I know I’d struggle to get an accurate measurement
yeah my Pro MX ranges up and down from the trainer power but usually within 10 watts (lower) i find which is +/- 3%. Hard to say too since ERG smooths everything out.
On wheel-on trainers, I’d calibrate before every workout. The big variable was the tire on the roller. Losses depend on tire, tire pressure, force against roller, tire temp… I’d ride ~10 min and then do a calibration before every workout. In my experience with direct drive trainers, they vary very very little, so I calibrate rarely, usually only before an FTP test, but not before ordinary workouts. Typically I’ll do it right after the workout that precedes the test so that the trainer is fully warmed up.
My understanding is that when you are “calibrating” your pedal or crank powermeter on the bike it is actually a zero offset - meaning ensuring that it reads as 0W when there is no torque being applied. This is why you put the pedal to 6’o’clock - to ensure that the pedal torques are in a balanced and known direction. I’ve never noticed a non-zero offset myself.
When you do a spindown calibration on a trainer it is measuring the spindown resistance at a measured temperature and using that to set (“calibrate”) the mechanical resistance when no electronic resistance is being applied. It seems best practice to do that under a normal operating temperature. I think that most modern trainers and powermeters do temperature compensation dynamically, so temperature variation should be less of an issue. In my experience, trainer calibration is most needed when moving bikes on/off the trainer.
Back in the day “real” calibration involved using heavy weights to generate known torques …
I wonder if I’ll see any difference to my power data with double sided instead of single sided. (I have a 2017 Be Pro S, but it can’t be swapped easy and a 4iiii V2 crank)