I did this same switch-over about a year and a half ago.
I had been working on a dumb trainer with virtual watts. I wasn’t sure how my watts were going to transfer over.
It all depends on how well you matched up your old dumb trainer in the app. It was a compatible trainer then your FTP and MAP should be pretty similar, but your AC and NM on the Kickr will be a lot higher since it will be actual power. But if you were just guessing as to which trainer to use for virtual watts (as I was) it all depends on which one you were using.
Since you’re already on a dumb trainer then the easiest way to transition is to start with level mode. After connecting your new Kickr Core, ride easy for 10 minutes and then do a calibration spin down in the Wahoo app. After that start up SYSTM, connect your new Kickr, change it from Erg mode to level 1 and just ride any open workout just to get the feel for how much effort it takes to hold any random power value. Don’t hold back. Try out some sprints and some couple minute efforts. Shift your gears around and feel the difference.
After that you can do some lower target rides on ERG mode - like Recharger - using your current 4DP numbers and feel how they compare.
Once you’ve done a couple workouts in level mode and erg mode you’ll have a good feel for the differences between your trainers. That should at least give you some idea of what power you’ll hold on your new Kickr.
Then you can do a Full Frontal. And the beauty of Full Frontal is you’re supposed to do it all in Level mode. So there will be no worries about ERG mode. Assuming you use the same or similar size cassette to the one you have on your bike, you should be able to ride similar gears for your test.
After that you’ll have your 4DP numbers in real watts instead of virtual watts. And then you can try out some workouts in ERG mode. What workouts you try first are up to you and mood.
Personally, I found I had accurately picked a compatible dumb trainer, so my old Virtual FTP was almost exactly the same as my new FTP on my Kickr Core.
The biggest difference between a dumb trainer and ERG mode is that the resistance will increase as you lower your cadence, and vice-versa. So, when you get tired you can end up dropping your cadence to get some rest and end up in the “ERG mode death spiral” and locking up. On the opposite spectrum, when you’re feeling really good you can end up riding a super high cadence. And you’ll want to get used to spinning up your cadence right before a Power Target jump so that you don’t get caught out by the resistance increase forcing you into the Erg death spiral.
It may sound like a lot, but it’s really just getting a feel for it and the learning curve can actually be quite small. I thought I was going to hate ERG mode (there are some riders who intensely despise it), but I actually love it maybe a bit too much. lol.
Anyway, that’s a lot. Let us know how it goes, and I hope you enjoy your new trainer!
