OK THANKS, this was very usefull but it still doesnt solve the mystery of how the hell cube is selling attain frame bikes with double cranksets
I will quote the important part that solves the problem for any1 interested:
"This was the final solution which I thought of. I found a road triple crankset, and measured the spindle length to be 112.5mm, which is 2.5mm longer than the road double or Alfine crankset. I also used a MTB BB, which have BB cups of 10mm wide on each side, instead of the 11mm of a road BB. Together, I managed to get an extra 2.5+1+1 = 4.5mm of spindle length on the left side!"