Switching from virtual power to "real" power

JClishe_

I'm looking for someone to sanity check my thinking here, or give me some guidance if I'm off base.

I do not have a power meter, but I've been training all OS with Trainer Road virtual power. I'll be buying a PM within the next 4-6 weeks, probably a Quark Riken. Probably closer to 4 weeks out since I'm going to the Blue Ridge camp and I want the PM for that. Anyway my thinking was that once the Quark is installed and calibrated, I'll do a bike test using virtual power on TR and "real" power from the Quark to either my 310xt or an Edge 810 that I plan to buy. I figure that by testing with virtual power on TR I'll be able to track my improvement from previous virtual power tests, and by also have "real" power data from the Quarq, I can use that to calculate my FTP values going forward, since I'll be getting off the trainer soon and moving outside.

Does that make sense?

Jason

jaleslie

Yes, that makes perfect sense.  If you only test with real power, you will not be able to quantify the gains you've made in the past couple of months.  Going forward, you will use your power meter always, and never virtual power anymore.  So, for just this one time, you will test once, measuring the results with two different tools simultaneously.  Exactly how to do that, I'm not 100% sure....I think if you just leave the TR settings alone, but have a head unit (Garmin whatever) also running and paired to the crank based PM, you will see two different sets of numbers, but the same graph/profile....just may be 20-40-60watts higher or lower.  For me, when I switched, it was about 40 watts different (lower...but it's a number after all).  

Garmin paired to PM....TR set to virtual power.  The TR guys might even want you to send you the two files so they could compare?

Good question and good thinking!

Peter Noyes

I went through this and did the exact same thing. I had my watch paired to the new PM, but I left Trainer Road in virtual power and then figured out the ratio. I also lost a whole lot of watts going through the transition, prepare yourself for a potential reality check!

Also, you can clear all of your power records in trainer road so you can start fresh.

JClishe_

Awesome, thanks a lot guys, this is what I wanted to hear. Well everything except the part about losing watts, but I expected that anyway.

Gordon Cherwoniak

Not much to add other than I agree with the previous to see your gains set up both devices.  This will definitely ease the pain especially if the Quark number is significantly lower.  Only compare the TR number for the OS improvement then discard and use the Quark numbers going forward.  

Remember that many people also see a lower power indoors so you could even set yourself up to do another test outdoors when you return from Blue Ridge camp or even before should you enjoy testing.  The number from the trainer will be good enough and you should really get outdoors and just ride with the PM for a couple weeks.

climbhard00

Jason. I'm doing the same as you. My PM is in the mail. I'm anxious to see what the +/- difference is between virtual and real power. Post up your findings once you get it all dialed in.

Brad Marcus

@jason - I did a similar conversion, but from a powermeter mounted on my trainer (cycleops powerbeam pro) to my quarq. The power readings are definitely different, as you should expect making the move from TR to real power. But, I did what you're planning to do and tested using the 'old' pm (in your case TR), with the new (quarq) running separately to record the data. You can go back and convert it as needed after the test to check your differences. But, at the end of the day, stay consistent using one or the other because it's only a number. Use this number as a bench mark to build on going forward.

[Deleted User]

I switched last March from TR Virtual Power to the Quarq Riken and did the same thing you are planning with the FTP test. Amazingly the Virtual Power and Quarq Power numbers were only 2 watts apart.