Just How Far Off Is Virtual Power on Rollers

[timothyh]

@mcneese.chad

Virtual Power Curves for any devices TR offers came from actual testing of a bike and power meter. Assuming you have the same exact model of rollers they used (not a generic option) the key variable in this relates to the tires.

I wonder if the VP curve accounts for weight. Resistance is proportional to weight for rollers only, and not just rider weight but system ie. bike+rider weight. If not, this is the most likely culpit - OP is a bit heavier than the average bear.

@Trackdom, here’s Chad fielding essentially the same question from 3 years ago:

Trainer resistance suddenly harder

Yes, retest. The timeline is a bit confusing, but ANY TIME you change ANY equipment as part of a Virtual Power setup, you must retest. You did it properly with the tire change. But I don’t see that you retested after swapping to the rollers. Without a dedicated power meter, you can’t just swap between trainers or rollers and expect the VP numbers to align. They just don’t work that way. So a test in each device is necessary. And you can’t likely use the same FTP on both devices, unless you…

Get after that FTP test!