So I moved from a saris fluid trainer 2 with a wahoo speed sensor to a kickr core and I am starting to have some concerns. With the kickr I feel like I am working so much harder than the saris. I did do all the factory spinddowns and calibration things and am pretty sure the kickr is working correctly (wahoo support taking there sweet time getting back to me). This week has been all endurance rides and they take so much more effort than I am used to with saris. I have a ramp test next Monday so I will be able to see my ftp with the kickr but its hard not to jump to the conclusion that all the work I did (3 months) was kinda shit (I know it helped but). I am coming from no cycling background doing low volume rolling road race and in the build phase. What’s the best way to deal with this situation?
How did you measure your power? It sounds like you used the virtual power estimate before, and now the smart trainer’s power? They will be different, and your FTP will be different. You have to do a new FTP test.
Sorry I forgot that part, I did virtual power. Ok sounds good.
Yeah, unfortunately virtual power is really just an estimate, and often very different from power actually measured.
You should do a new FTP test everytime you change your power source (like switching to a different smart trainer or powermeter).
The good news is, its unlikely there is anything wrong with your new smart trainer!
This.
The paeticular Kickr I am using is pretty far off power wise. But it doesn’t matter. Just do a ramp test with that trainer and use that for training. If you aren’t using a PM outside then it is a non issue.
To splash
Yeah the difference is really something and makes me wish I had gotten a power meter. Good to know cause I thought I was going crazy because of how much more difficult the kickr is.
Even from a smart trainer with wheel on to smart trainer direct drive you’ll see a difference in power
Yes, the moral of this story is to “NEVER assume that any two power devices match”… because they rarely do.
You should retest FTP ANYTIME you change you power measurement devices, no matter what types are involved.
Now they tell me 
Like so many things in life…
“You don’t know what you don’t know.” 
Confirmed, I was in almost the same situation with the
same equipment.
I was expecting a drop in power going from virtual to real power. I think I heard the drop was roughly 10-15% on average, however, if it recall for me it was even more.
I think you will want to wipe out your history in TR settings so your virtual power history is not compared with your real power history.
Lastly, as mentioned, who cares about the actual numbers as long as they are progressing in the right direction. So I suspect you didn’t lose or waste any time.
Happy training
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You really don’t need to wipe it out.
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Creating seasons associated with the power data change is a cleaner way to do it. This gives you “new records” based on the new power meter and still have the old data in place.
- Totally correct. The numbers may change (think of it like changing units from one system to another), but your fitness is still the same no matter what “yardstick” you are using. All the prior training got you what you got, and that is great. You just have a different tool for measurement now.
But the numbers man! It’s…all…about…the…numbers…man! 
Will try and attempt a ramp test tomorrow if the power doesn’t go out and see what happens. Thanks for all the help, appreciate it.
My ftp actually went up. Maybe the cycling gods were with me or it was the pretzilla bun (recommended) or scraping my forearm against my chainring (not recommended). Doing the ramp test with kickr was so much better than the saris.
Right on! Congrats 