Hi all, last week I installed a Kickr core to replace a wheel on Tacx bushido. Trainings felt supereasy this week so decided to do Half Monty today - previous results were about 6 months old. Feelings confirmed - huge increases in FTP and MAP, both 15% higher. Is that normal? Or should I spin down the Core once more and bring myself back to earth?
Not exactly the same as you but when I changed from virtual power to pedal-based power meter my wattages went up by about 50-60%
I could well believe there is a discrepancy between different types of trainer. The only thing to do really is to retest with the new kit.
You can definitely get different power measurements from different devices. I’m not an expert but 15% change doesn’t seem out of the realm of possibility to me. However, maybe some of that is your improvement and some is the device (you mentioned it suddenly seemed easier). I have a roller-based trainer now (not direct drive). The algorithm in those trainers does not “know” the rotational inertia in the bike wheel and powertrain - it is guessing on that parameter when calibrating. I would tend to think of the direct drive as a bit more accurate, and pedal or crank measurement as better yet. As long as you set new targets based on your new measurement (seems required for a new trainer or power device) then you are all set in any case.
If this was a sudden change after swapping trainer then I would think the gain is almost certainly down to the trainer. The good news is that your Kickr is likely to be more accurate than your old wheel-on trainer. So your new higher numbers are probably genuine. I would do another spin down and call it good if things don’t change.