As the title says, my 4iiii reads 25-30 watts lower on the road compared to the turbo than the road for the same heart rate. Has anyone else experienced this? Any solutions?
Hey there,
For starters, are you calibrating your power meter before every ride (indoors or outdoors)?
If not, we’d recommend doing so. That will ensure your power meter will read as accurately as possible as you train.
These instructions from 4iiii go over how:
You can also do so within the TR app if you’re on the turbo:
Give that a shot first, but let us know if power meter calibration isn’t the issue and we can look into further troubleshooting steps.
assume that if the above good advice is not the issue, then maybe temperature is. If you do not have good air circulation when indoors on the trainer then you may be actually over heating indoors which can lead to elevated heart rate as a cooling function? Also 20-35 watts at what average wattage? or is it the same no matter what wattage?
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Another thing to look at is leg balance, though without a dual-sided PM that’ll be tougher to identify.
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Shimano 4iiiiiiiiiii? Make sure the pinch bolts are TIGHT. Should be 12-15lb, which is tight with a 6-8in long lever.
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Quite difficult to work out what is going on without adding another power meter into the mix.
Its not just the 4iiii you are moving from inside to outside - you are moving yourself and your HRM too!
If you could borrow a pedal based PM you could work out if its the 4iiii or the heart rate measurement that is changing.
Probably one of the following:
- temperature
- bike position
- interference
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Turbo could be leaning to one side!