What is VirtualPower™?

VirtualPower™ turns your indoor cycling trainer into a power meter. Just hook up an ANT+ speed sensor and select your trainer from the list of power sources. When you start to ride, your speed will be converted to power based on the known power curve for the trainer.

How does this work?

Every trainer gets harder the faster you go. We've quantified this resistance curve into a formula that is specific to your trainer.  This allows us to plug in your current speed and output watts.  We've built this into our software so it happens on the fly and is seamless to you.

How accurate is it?

In our unscientific tests with our power taps and Kurt Kinetic Road Machines we were within 3 avg watts for our intervals...so pretty darn accurate.  You can get a run down on the Kurt Kinetic Virtual Power Curve here.

So you are saying that instead of spending $800-$3000 on a power meter, I can spend a few hundred on a trainer and $40 on a speed sensor and train with power? 

Yes. Power meters are great to race and train with but if you're not quite ready to make the leap or just want to get a feel for training with power, this is a great option.  Obviously this wont give you power data for your outdoor rides.

We think VirtualPower is a much better way to train than by heartrate or RPE.  But when it comes down to it, a power meter will still be more accurate.

What affects VirtualPower™?

With VirtualPower™, we are effectively measuring power at the trainer. That means that any variance in the drive train between your pedals and the trainer can have an effect. When training with VirtualPower, make sure your tire pressure and tension against the wheel are the same each time you ride.  This will give you consistent power readings.

Different tensions on the wheel effect rolling resistance and can skew your readings.  The important thing is to have consistent and repeatable readings to train with.  That's why having the same tension on your tire and the same tire pressure each ride is important.

Here's a good example.  Below I have power from a PowerTap, which claims +-1.5% accuracy, graphed with Virtual Power.  My setup was on a Kurt Kinetic Road Machine with a contintential trainer tire at 120psi.  I cranked down the rear wheel 1.5 times.

VirtualPower vs Power Tap (no offset)

Kurt Kinetic Power Curve Virtual Power

 

You can see that VirtualPower tracks really well with power, but is higher the entire ride.  This is due to rolling resistance (tire pressure, tire tread, tire tightness).

With my setup my y-intercept offset is -30 watts.  If I lower my VirtualPower reading by -30 watts I get this graph.

VirtualPower vs PowerTap (adjusted offset)

Kurt Kinetic Power Curve Virtual Power Adjusted

Now you can see VirtualPower graphs really close to a PowerTap.  These are even more compelling results when you take into account the PowerTap has a +-1.5% accuracy.

Do you really need to care about those -30 watts?  Well that depends on how much money you want to spend.  If you just want consistent power numbers between workouts, then VirtualPower is good for you.  If you want absolute power numbers that you can use to compare to other people, then we recommend getting an ANT+ power meter.

Read more about getting the most out of VirtualPower™ here:  http://support.trainerroad.com/entries/20636891-how-do-i-get-the-most-out-of-virtualpower

What trainers are supported?

We have support for several fluid, mag, and wind trainers now. We've seen great results with the fluid trainers that don't have variable resistance since you can get the biggest range of resistance by just changing cadence and gears.

All of the trainers listed multiple times where only the last number changes are for each of the resistance levels of that trainer. Set the resistance on your trainer, choose the corresponding trainer and use your gears to change resistance.

We also support several rollers.  

Here's the list of trainers/turbos/rollers we support:

  1. (Beta) 1Up USA - CPR A-2000 black flywheel
  2. (Beta) 1UP USA CPR-A-2000 6 Pockets
  3. (Beta) 1UP USA CPR-A-2000 Inner Pockets
  4. (Beta) 1UP USA CPR-A-2000 Outer Pockets
  5. (Beta) BlackBurn Basic Mag 3 level 1
  6. (Beta) BlackBurn Basic Mag 3 level 2
  7. (Beta) BlackBurn Basic Mag 3 level 3
  8. (Beta) BlackBurn Fluid
  9. (Beta) BlackBurn Mag 6 level 1
  10. (Beta) BlackBurn Mag 6 level 2
  11. (Beta) BlackBurn Mag 6 level 3
  12. (Beta) BlackBurn Mag 6 level 4
  13. (Beta) BlackBurn Mag 6 level 5
  14. (Beta) BlackBurn Mag 6 level 6
  15. (Beta) Cateye CS-1000
  16. (Beta) CycleOps Fluid 2
  17. (Beta) CycleOps Jet Fluid Pro
  18. (Beta) Cycleops Mag 3
  19. (Beta) Cycleops Mag 4
  20. (Beta) Cycleops Mag 5
  21. (Beta) CycleOps Magneto
  22. (Beta) CycleOps Wind
  23. (Beta) Elite Crono HydroMag 1
  24. (Beta) Elite Crono HydroMag 2
  25. (Beta) Elite Crono HydroMag 3
  26. (Beta) Elite Crono HydroMag 4
  27. (Beta) Elite Crono HydroMag 5
  28. (Beta) Elite Crono Mag 1
  29. (Beta) Elite Crono Mag 2
  30. (Beta) Elite Crono Mag 3
  31. (Beta) Elite Crono Mag 4
  32. (Beta) Elite Crono Mag 5
  33. (Beta) Elite Hydromag 1
  34. (Beta) Elite Hydromag 2
  35. (Beta) Elite Hydromag 3
  36. (Beta) Elite Hydromag 4
  37. (Beta) Elite Hydromag 5
  38. (Beta) Elite Mag 1
  39. (Beta) Elite Mag 2
  40. (Beta) Elite Mag 3
  41. (Beta) Elite Mag 4
  42. (Beta) Elite Mag 5
  43. (Beta) Elite PowerFluid
  44. (Beta) Elite PowerMag 1
  45. (Beta) Elite PowerMag 2
  46. (Beta) Elite PowerMag 3
  47. (Beta) Elite PowerMag 4
  48. (Beta) Elite PowerMag 5
  49. (Beta) Elite PowerMag 6
  50. (Beta) Elite PowerMag 7
  51. (Beta) Elite PowerMag 8
  52. (Beta) Elite SuperCrono Forte 1
  53. (Beta) Elite SuperCrono Forte 12
  54. (Beta) Elite SuperCrono Forte 16
  55. (Beta) Elite SuperCrono Forte 4
  56. (Beta) Elite SuperCrono Forte 8
  57. (Beta) Elite Volare Mag Alu 1
  58. (Beta) Elite Volare Mag Alu 2
  59. (Beta) Elite Volare Mag Alu 3
  60. (Beta) Elite Volare Mag Alu 4
  61. (Beta) Elite Volare Mag Alu 5
  62. (Beta) Kreitler 2.25 Drums
  63. (Beta) Kreitler 3.0 Drums
  64. (Beta) Kreitler 3.0 Drums, 1/2 fan, flywheel
  65. (Beta) Kreitler 3.0 Drums, flywheel
  66. (Beta) Kreitler 4.5 Drums
  67. (Beta) Kreitler 4.5 drums, 1/2 fan, flywheel
  68. (Beta) Lemond Revolution
  69. (Beta) Sportscrafters Alu Rollers + mag 5
  70. (Beta) SuperMagneto Pro Easy
  71. (Beta) SuperMagneto Pro Interval
  72. (Beta) SuperMagneto Pro Mountain
  73. (Beta) SuperMagneto Pro Road
  74. (Beta) Tacx Antares Rollers
  75. (Beta) Tacx Bushido 0.0% slope
  76. (Beta) Tacx Bushido 1.0% slope
  77. (Beta) Tacx Flow 0%
  78. (Beta) Tacx Flow 1%
  79. (Beta) Tacx Flow 2%
  80. (Beta) Travel Trac Century Fluid
  81. (Beta) Travel Trac rollers 2
  82. (Beta) TravelTrac Fluid+ 1
  83. (Beta) TravelTrac Fluid+ 2
  84. (Beta) TravelTrac Fluid+ 3
  85. (Beta) TravelTrac Fluid+ 4
  86. (Beta) TravelTrac Fluid+ 5
  87. (Beta) TravelTrac Millennium V level 1
  88. (Beta) TravelTrac Millennium V level 2
  89. (Beta) TruTrainer Rollers
  90. Bike Technologies - Advanced Training System
  91. E-Motion Rollers @0, 180#
  92. E-Motion Rollers @1, 180#
  93. E-Motion Rollers @2, 180#
  94. E-Motion Rollers @3, 180#
  95. Elite Fluid Alu AKA Chrono Fluid ElastoGel
  96. Elite Volare Fluid
  97. JetBlack JBT-Z1FLUID Z1 trainer
  98. Kurt Kinetic AC Pro
  99. Kurt Kinetic Cyclone
  100. Kurt Kinetic Road Machine
  101. Kurt Kinetic Rock and Roll
  102. Minoura 850 5
  103. Minoura 850 H
  104. Minoura M80-R/M70-R/B60 1
  105. Minoura M80-R/M70-R/B60 2
  106. Minoura M80-R/M70-R/B60 3
  107. Minoura M80-R/M70-R/B60 4
  108. Minoura M80-R/M70-R/B60 5
  109. Minoura M80-R/M70-R/B60 H
  110. Minoura M80-R/M70-R/B60 L
  111. Minoura Mag 500/850LW 1
  112. Minoura Mag 500/850LW 2
  113. Minoura Mag 500/850LW 3
  114. Minoura Mag 500/850LW 4
  115. Minoura Mag 500/850LW 5
  116. Minoura Mag 500/850LW H
  117. Minoura Mag 500/850LW L
  118. Minoura RDA2429/RDA80 1
  119. Minoura RDA2429/RDA80 2
  120. Minoura RDA2429/RDA80 3
  121. Minoura RDA2429/RDA80 4
  122. Minoura RDA2429/RDA80 5
  123. Minoura RDA2429/RDA80 H
  124. Minoura RDA2429/RDA80 L
  125. Minoura V270 / V130 1
  126. Minoura V270 / V130 2
  127. Minoura V270 / V130 3
  128. Minoura V270 / V130 4
  129. Minoura V270 / V130 5
  130. Minoura V270 / V130 H
  131. Minoura V270 / V130 L
  132. Minoura VFS
  133. Minoura VFS-R 1
  134. Minoura VFS-R 2
  135. Minoura VFS-R 3
  136. Minoura VFS-R 4
  137. Minoura VFS-R 5
  138. Minoura VFS-R H
  139. Minoura VFS-R L
  140. Tacx Booster 1
  141. Tacx Booster 10
  142. Tacx Booster 2
  143. Tacx Booster 3
  144. Tacx Booster 4
  145. Tacx Booster 5
  146. Tacx Booster 6
  147. Tacx Booster 7
  148. Tacx Booster 8
  149. Tacx Booster 9
  150. Tacx Satori 1
  151. Tacx Satori 10
  152. Tacx Satori 2
  153. Tacx Satori 3
  154. Tacx Satori 4
  155. Tacx Satori 5
  156. Tacx Satori 6
  157. Tacx Satori 7
  158. Tacx Satori 8
  159. Tacx Satori 9
  160. Tacx Sirius 1
  161. Tacx Sirius 10
  162. Tacx Sirius 2
  163. Tacx Sirius 3
  164. Tacx Sirius 4
  165. Tacx Sirius 5
  166. Tacx Sirius 6
  167. Tacx Sirius 7
  168. Tacx Sirius 8
  169. Tacx Sirius 9

What if my trainer isn't in the list?

You can post on our Forums what trainer you'd like to have supported. To add a new trainer, we need power data at speeds in 5 mph increments between 5 and 30 mph. If you have a power meter you can help us with this. You could also contact your trainer manufacturer asking for this information. 

Any trainers with variable resistance that aren't in steps (like a spin bike that you crank down the tension) won't work.

For some trainers, heat affects the readings too much.  You might start out with accurate readings but after a while you could be off as much as 20+ watts due to heat.

If you're in the market for a new trainer to use with VirtualPower we recommend the Kurt Kinetic Road Machine or the Kurt Kinetic Rock n Roll.  We've seen great results with these trainers and their resistance curves are less susceptible to heat.

What are the "Beta" trainers in your list mean?

Some of our Trainers have 'Beta" before them in the list,  These are trainers that have published power curves, but we aren't 100% that they are accurate.  We might change these curves and improve the formula.  We'll let you know when we do.  Our goal is to publish data on all the trainers we support for you to review the accuracy.

How do I start?

Choose a plan from our Plans page to suit your goals. Then choose either the 20 minute or 8 minute test workout as your first ride. Each one takes an hour. This will determine your FTP for VirtualPower™. Since all other workouts are scaled to this value, as long as you keep your setup consistent, all of the other workouts will be scaled correctly.

You can read more about your first ride here:  http://support.trainerroad.com/entries/20648407-what-workout-should-i-start-with

 

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