In my setup, the SMART trainer measures mostly about 10% more power than the more trustworthy Favero pedal power meters. I do appreciate the PowerMatch tool in TrainerDay that helps to compensate for these differences.
However, I would like to use these pedals on the road bike without having to spend another $500 on a second set of power meters.
Perhaps there is already another way to simply change the trainer power meter reading linearly? I would be interested in an alternate simple (linear) PowerMatch option allowing rough adjustments without a second meter.
I presume you’re not using the same bike on the trainer hence this question?
What about just scaling UP or DOWN the workouts so that it still hits the power needed?
DIfferent bikes; actually a SMART-bike indoors.
The goal is consistent power readings and ERG-mode workouts.
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This would be needed to have reasonable accurate training data on Strava, Intervals.icu, etc.
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Ok you are the first to ask for this but I understand the request. To be transparent unless more people get excited about this I don’t think it will happen soon. It’s a reasonable request so I am not opposed to it.
He´s not the first. I´ve asked this very early on.
Simple value to add or substract
Fixed % to modify
Funny (or sorry), I usually remember this stuff. I guess I lost that one. Makes sense.
I don’t need it anymore now. My newest smarttrainer is very close to my Favero pedals.
But it’s an easy fix for any trainer that has a predictable offset. x = a + b * y.
Set a to adjust a fixed offset, b to adjust a % offset and both if needed.
It sounds easy but some how I think it won’t be. You have to adjust the power output as well as the target and graph and then you have to see what happens one someone uses HR mode or power match… It all gets kind of ugly quickly. At first I was thinking this sounded easy too but now after doing these things that seem easy I realize frequently they are not.
??? I don’t understand what you’re saying here.
Example: (case 1: both smarttrainer and power meter are connected to the app)
- The workout specifies a target of 150W
- The smarttrainer sets a resistance that results in a Power meter measurement that is 10 W low = 140W
- All you need to change is the value being forwarded to the smarttrainer. Send 160W iso 150W. Keep that change behind the screens.
- Target displayed remains 150W. Recorded value is the one from the power meter ~= 150W
Same example: (case 2: only smarttrainer is connected to the app, offset is known as being 10W)
- The workout specifies a target of 150W
- Change the value being forwarded to the smarttrainer by adding the offset. Send 160W iso 150W. Keep that change behind the screens.
- Target displayed remains 150W. Recorded value is the one from the smarttrainer and needs to be reduced by the offset value.
With regards to PowerMatch:
- Do not allow automatic PowerMatch when Offset mode is active. After all, if the user knows that the difference between smarttrainer and Power meter can be mathematically described, you don’t need PowerMatch
- TrainerRoad has been doing this for years. You toggle PowerMatch between ‘auto’ or ‘manual’. Manual being an offset described by a formula.
Programming wise:
- Add the offset in the last step when you send the command stream to the trainer
- If recording is done from the trainer, subtract the offset from the incoming stream and handle all the rest as it is now.
Does that sound correct or am I not seeing this correctly?
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Some how this stuff always has unexpected consequences. For example when switching to HR mode we use averages from the previous modes. Also this should work for slope mode too. It will cause bugs and have a tail of extra development. I am a software developer / manager for 30+ years so I can usually smell when things will grow (and other times I am an optimist and fail to see it). We could get lucky and it goes quickly but I doubt it as I said. I again am not against it, it’s just not something I willing to try to throw in quickly. Needs to be where there is some down time.