I ride 10,000+ km a year outside with an ftp of around 280w (71kgs). I ride in plenty of fast group rides and chain gangs.
But I have never ridden indoors until this week. I got the recent zwift bike and kicker core bundle deal and have set it up.
Outdoors z2 for me is around 210w. But on the trainer this power feels very hard on the legs, like i am doing leg presses at the gym rather than cycling.
After about 5 mins I start to feel fatigued and after 30 mins I have very heavy legs and have to stop. My heart rate is elevated for a z2 ride (155 instead of a more normal 145) but no where near maximum (195).
I assumed the problem was a calibration issue for the trainer, but it seems the kickr core has auto calibration so it’s not that.
Whats going on? What am I doing wrong?
EDIT - Thanks for all the replies. I have now solved the problem. Turns out I was an idiot and I forgot to install the drive side spacer so the cog body was rubbing against the zwift ride frame. Retest ftp after it is installed and ftp up to 280 even without a fan. And it feels like cycling rather than doing leg press machine at the gym. So all good now.