Power curve adjustment on Virtual Power?

I’ve been using TR for about three months now, training with a LeMond Revolution with Virtual Power indoors while recording my rides with a PowerTap G3 outdoors. A friend recently purchased an Assioma Uno so I offered to bring my trainer over for him to do a Step Test so that he would have an FTP estimate to start with.

During the test, I recorded the Assioma’s output on a laptop whilst also recording using Virtual Power on my phone (as I normally would at home) for comparison. Looking at the numbers, it seems Virtual Power reads consistently ~20 watts low across the board on my trainer. I know this is only one data point, and that it does not directly affect my training progress (outside of possibly having a TSS figure that is high for outdoor ride files), but I was hoping to be able to correct for the difference as it’s been bugging me since finding out. Is this even possible? Should I try adjusting the Virtual Power wheel size outside of the recommended 2070mm?

When training with VirtualPower, it is important to remember that consistency and precision are the most important variables when training indoors. Even if your VirtualPower readings are not 100% representative of your outdoor power, you can still reap the benefits of training with power as long as you use the same trainer and VirtualPower curve for each workout. Doing so means your results will be comparable, and you’ll be able to track your progress.

In theory, you could alter the circumference to adjust the power curve to more closely match your actual power, however, this is not something that we have experience doing, so it would require some guess and check work to get just right.

One fomula that may prove helpful in determining how much to change the circumference:

  • Speed km/h= (circumference)(RPM)(60) / (1000)(1000)

Let me know if there is anything else I can help you with!

I recently acquired a Lemond Revolution and noticed that TR lists the Power Source as Lemond Revolution Beta. Is this being worked on still or left as Beta for a reason?

I did that on my KK Rock & Roll before getting a smart trainer. The comparison was with a Stages single sided PM. It worked OK after a bit of trial & error. If you wanted to get really nerdy you could have different wheel circumferences for Endurance, Sweet Spot & VO2max sessions. I considered doing that but realised life was too short!

re: beta, probably a carryover from old TR days. The Adobe AIR version of TR used to have dozens of trainers listed as beta.

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Curious about this as well.

Also, does everyone use 2070 for their wheel circumference? Initially I used the default of 2096mm. I’ve just adjusted it to 2070mm after seeing a mention of that as the recommended setting.

Virtual power is so far proving to be awesome! My power bounces around like crazy though. I have smoothing set to 8 seconds now. Only issue is my power reading low or going way past my goal before I can settle in.