Yeah weight it all together on a proper scale.
The weights of kettler were as expected spot on. The belt weight less than 100 grams.
What freightened me most is that het number is higher and about the percentage I think it is off.
(Old ftp 233, new obtained just by doing an hour ride 278w).
I will however repeat this test once I have time and also do a climb test like the other guy suggested. (I live in Flanders so not that easy to find)
I can use the vector to train since I now know that 290-300 w means suffering and probably breaking when sustained too long. And 240 is quite chill and good for a long ride.
But I want to do an effort to be sure that the numbers are really correct (since that is what I paid for).
I keep you posted.