TrainerRoad and power
I'm still relatively new to cycling - this is only my second year of what I would call real cycling ever since I got a halfway decent road bike. Since I'm new, and only recently am learning about training with power - I don't have a power meter at all. This past January I signed on with TrainerRoad, more because of the structured workouts than anything else - I didn't know about EN at the time, so I did my own outseason bike work based on TR's workouts and power reporting.
I fully recognize that in a situation like this, the accuracy of power as reported by TR can be highly variable - factors such as which trainer you use (I have the Cycleops Fluid2), tire pressure, type of tire, tension of the drum, etc, all play a part in how 'off' the TR value may be compared to reality. Unfortunately, without a power meter, I can't tell whether it reports low, high, and by how much.
In the end, I realize that all that matters is that as long as my setup is consistent, improvement is improvement. But I'm curious if anyone else here has a power meter and used TR, and what your experience is in terms of TR's reported power and your power meter. It'd just be nice to know, for example, that X number of people report that it tends to be Y watts high or low.
I'm also curious how many others are in the same boat - no power meter, and using TR as the basis for FTP.
Comments
I would state that virtual power with TR is better than no power. I've followed along with some of their podcasts, blogs etc. and they will tell you it's not perfect. According to them, the biggest issue is getting the rolling resistance right. Their recommendations are to inflate tires to the same pressure all the time, use the same tire, tighten it the same every time. The more variability in set up, the less consistent the results.
They also comment that some trainers are better than others. Can't recall comments on yours, but my Kurt Kenetic happened to be highly rated. The issue seems to be that as the units heat up, the power tends to drift for some cheaper trainer models, so the longer you ride, the less accurate the results.
They started off using data provided by the manufactures to dump power curve data into their program but now have purchased a piece of equipment to do all the testing themselves, hoping to improve the accuracy of the math algorithms.
Having said all that, I have a Computrainer (CT) and a Kurt Kenetic (KK) and a PT. Sometimes I'll ride and capture PT data with my Garmin and then compare to TR data. With the CT I find it is off quite a bit until I calibrate the unit, about 10 minutes in. The errors are not consistent, sometimes over, sometimes under. After calibration, the numbers are very close. With the KK, numbers are fairly close. within 5 - 10 watts.
I'll always follow the TR data because it's easy and use the +/- to adjust power if necessary.